Miscellaneous

This section lists differences and problems with the port(s) that don’t fit into other categories, as well as discusses several myths around the (supposed) SA1 flaws.

Title screen, menus and branding

The Dreamcast version had an animated Sonic Team logo with an ocean background (click the image to get an animated gif). In SADX it was replaced with a static Sonic Team logo. Not a big deal, but how is this better than the original?

Dreamcast
Gamecube/PC

The title screen is also different between versions. The Japanese and original US releases of Sonic Adventure had a static image with a stylized “Sonic Adventure” logo. The “PressStartButton” text was static in the Japanese version, but the US version added a fade animation. The International release added an animated ripple effect to the background and changed the logo slightly:

Sonic Adventure US
Sonic Adventure International

SADX replaced the ripple effect with a scrolling background, added a render of Sonic and made the logo more generic. You can still see the original title screen in nextgen console ports if you don’t buy the “DX” DLC. Whether the original or the DX title screen is better is a matter of opinion, but it’s pretty obvious that the DX logo looks a lot more basic. Some might argue it’s a bit too cheap for a “director’s cut”.

The Pause menu received a slight redesign in SADX. Now it tells you which mode you’re playing (Adventure, Trial or Mission), a somewhat useless feature, though not a downgrade if you don’t mind missing shadows and the awkward look with a smaller font. SADX also adds Adventure Field maps and an option to switch between automatic and manual camera, both of which are nice additions. However, the visual changes are somewhat less impressive. The rounded corners of the background rectangle were removed, and gradients everywhere except the buttons were disabled. The buttons were also made blue instead of teal. Both versions look kind of generic, but is the SADX one really better?

Dreamcast
PC 2004

Intro movie and FMV cutscenes

Let’s talk about the intro movie and FMVs. This is a bit unusual because out of all versions of the game the Gamecube version has the best quality intro movie. The Dreamcast version’s intro resolution is 320×448, and the video gets stretched horizontally to 640 with black borders on top and bottom to make it 640×480. The FMVs are even lower quality – 320×256 stretched to 640×480. The Gamecube version has the same FMVs as the original game, but the quality of the intro video is noticeably higher, with better bitrate and it’s already 640×448 so it doesn’t need horizontal stretching. One difference with the new intro is the logo transition, which lost the background animation and became more generic. Click each image to get an animated gif:

Dreamcast
Gamecube

Interestingly the 2004 PC port is a bit special in this regard. Its intro and FMVs are in true 640×480 without black borders, which means the PC version’s intro has more visible details than the Dreamcast and Gamecube intros. The Steam and nextgen console versions use the same FMVs as the Dreamcast/Gamecube (the intro is different though, but let’s discuss that later). As a result, the 2004 PC port has the best looking FMVs:

Dreamcast/Gamecube/PS3/X360/Steam
PC 2004

The 2004 PC port has the best quality FMVs, but the same can’t be said about the intro. Although the intro itself is in 640×480 without black borders, it suffers from poor compression. The Steam and nextgen console ports have intros based on the PC one but recompressed, so their quality is even worse. Below you can see clickable comparisons of the same frames extracted from each version’s intro movie:

Dreamcast

Gamecube

2004 PC port

Playstation 3/Xbox 360

Steam

The winner here is the Gamecube version, while the Dreamcast version looks worse or close enough depending on the scene. The 2004 PC version looks worse than Gamecube, sometimes even worse than Dreamcast, and the Steam/nextgen console ports have the worst looking intro movie out of all ports. Let’s not forget that the Steam/nextgen console ports also have the lower quality FMV cutscenes from the Dreamcast version, even though the higher quality ones from the 2004 PC port were already available.

The nextgen console ports have an intro movie featuring the “original” SA1 logo. This would’ve been a nice homage to the original game (if we forget for a moment that those ports try to fool you into thinking they ARE the original game), but the animation for the logo transition lacks some effects and isn’t very faithful to the original. Although the logo itself looks clearer in the new intro, the original intro has a better animation. In addition, the nextgen console intro is slightly messed up – when the letters zoom out, the image is cut off on the right, which makes the letters C and E look strange.

Dreamcast
PS3/X360

A closer look at the intro movie (props to Speeps and McAleeCh for discovering this) reveals some interesting details. It appears that, despite the higher overall quality, the intro movie in all ports is based on an earlier, unfinished version of the video similar to the intro used in a beta version of Sonic Adventure known as the “Autodemo” prototype. The SADX intro has more in common with the Autodemo than the final Dreamcast intro, which has different details and appears more complete overall. This post by McAleeCh documents the process of recreating the SA1 intro in higher quality from several sources, and is great read if you’re interested in detailed differences between various versions of the intro. For now, however, let’s focus on the most noticeable parts.

The majority of Station Square shots in the SADX intro look like the Autodemo intro, while the final Dreamcast version uses shots from Super Sonic’s story. For example, in the following shot the Gamecube version is missing some fog/lighting details like the Autodemo:

Similarly, the intro on the Gamecube is missing some pedestrians, and the cars in this scene are arranged differently:

The following shot crossfades with different timing in the SADX intro. Although it doesn’t look “bad” per se, it’s clearly more like the Autodemo rather than the final version:

A notable difference is Tails’ expression in the intro. It’s also clearly from the Autodemo:

Finally, here’s one more hilarious detail about the SADX intro. The numbers on Gamma’s body are simply slapped on (the Autodemo intro doesn’t have them at all), while in the Dreamcast version they have lighting and are consistent with the shape of Gamma’s body:

With all the above examples there’s little doubt that the SADX intro is based on an unfinished version of the final game’s intro. Thankfully it isn’t an exact copy of the Autodemo’s intro. The Autodemo’s intro is 320×240 stretched to 576×480 with black bars on each side to make it 640×480, so at least they had courtesy to use a higher quality source for the SADX intro.

Another thing about SADX that feels unfinished is the FMV skip feature. On the Dreamcast you could only skip the Sonic Team logo and the intro movie, which is somewhat annoying. In SADX you can skip all videos by pressing Start or A, which is nice, but unlike the original game the skipped videos don’t fade out – instead they just cut immediately. Interestingly SADX does have a system for fading out videos, which is used on all videos except the intro movie (where it’s deliberately broken as the fades are built into the video file itself). This system could’ve been used easily to fade out videos when they’re skipped, but for some reason it isn’t implemented. Minor point, but it’s just another example of where the original game did better than the poorly executed SADX “improvements”.

Aspect ratio on the Gamecube

The Gamecube version of the game is rendered at an incorrect aspect ratio. While this was usually corrected automatically by older TVs, it’s difficult to get the game to scale properly on modern TVs and video capture hardware. Even on an emulator the aspect ratio is wrong, and the picture appears slightly squished horizontally. Here’s an image from Sonic Retro that uses footage captured from real hardware. Even though the zoom is different, you can still clearly see that Sonic is noticeably taller in the Gamecube screenshot in comparison to the PC version that uses the same Sonic model. You can also tell the aspect ratio is incorrect by the shape of the letter A in Amy’s name:

Subtitle font downgrades

One of the better known differences between SA1/SADX Gamecube and the PC version is that the PC port no longer uses the “Impress” subtitle font, but the difference is a bit deeper. Here’s a comparison of how the subtitle font looks in different versions of the game at the original resolution (top: Dreamcast, middle: SADX Gamecube, bottom: SADX PC):

Note: There’ve been claims that the subtitle font color is inaccurate on Dreamcast emulators, and that the font is supposed to be white on real hardware. This has been proven false – the font is not white on the Dreamcast, it uses a subtle dark gradient and is slightly transparent.

Note how the Gamecube version’s text looks a bit more washed out even though it’s supposedly the same font. It appears to have some kind of smoothing or texture filtering applied. It’s either an aspect ratio artifact, or it’s using font smoothing like in the PC version. More on that below.

SA1 and SADX Gamecube use the “Impress” font for English and the “Comic Sans” font for other European languages. There’s also a separate font for Japanese. Each of these fonts comes in a separate file that is loaded depending on the current language setting. In the PC port the font system was reworked, and a single font file is used at all times. The updated font is smaller, and some people say it looks worse than Impress or Comic Sans. It certainly looks more washed out than the Dreamcast version. Let’s have a closer look:

When I was restoring the original “Impress” font in the PC version I ran into this issue because even the original SA1 font data didn’t look quite right:

It appears that the PC version (and possibly the Gamecube version, to a lesser extent) applies a slightly transparent outline around the letters, which makes the font thicker and a bit harder on the eyes:

Disabling this feature made the subtitles look a lot better, even with the original SADX PC font!

Other minor differences

Here’s a minor, but interesting difference: all lines, such as Gamma’s laser scope or Big’s fishing line, are thinner in SADX.

Dreamcast
Gamecube
Dreamcast
PC 2004

Is SA1 a barely playable buggy mess? Yes and no.

For many years Sonic Adventure has had the reputation of a buggy game. There are many issues stemming from the game’s wonky collision system and weird camera behavior, which was common for games at the time. Yes, it is true that landing between platforms closely stuck together or spindash spamming into a wall can sometimes make Sonic clip through walls or fall through the floor. While these are definitely annoying, is Sonic Adventure almost unplayable because of such issues? No, not really.

SA1 doesn’t have nearly as many game-breaking bugs as other supposedly less buggy games it sometimes gets compared with – such as Super Mario 64 or Ocarina of Time. For example, there is a documented bug in SA1 that corrupts save files – getting the Crystal Ring upgrade in Final Story before fighting Perfect Chaos. With the game’s story taken into account, it’s a rather obscure bug that isn’t likely to happen during a regular playthrough. Other savegame corruptions may happen after glitching the characters into levels they don’t visit normally, such as Amy in Casinopolis. These glitches require fighting the game’s collision system and aren’t very easy to perform. They are unlikely to occur in regular gameplay.

Also, SA1 has no known bugs that interfere with gameplay in a fundamental way. The worst outcome of a gameplay bug in SA1 is an accidental death of the character. Sonic falling to his death on the first loop in Emerald Coast because the player didn’t hold forward is annoying, but compare that to the “Reverse Bottle Adventure” in Zelda or the glitch in Super Mario 64 that lets you skip through the whole game and beat it with 0 stars. While Super Mario 64 is a 1996 game, Majora’s Mask came out almost 2 years after the original Japanese release of SA1. In reality, all of these games are old and buggy, but SA1 is definitely not among the buggiest.

On top of that, SA1’s reputation has suffered a lot from misrepresentation by bloggers, youtubers and incompetent game journalists that either fail to do their research or just don’t care whether the issue really exists. Many of SA1 criticisms are fair. However, as more and more people can’t play the authentic version of the game on the Dreamcast, problems with Dreamcast emulators and pirated game rips are portrayed as inherent issues with the original game that SADX supposedly “fixed”. Some of such glitches are discussed below.

Control downgrades and myths about SA1 Dreamcast controls

Let’s talk about the controls too, since there seem to be a lot of myths and confusion about them. The controls in the original game were optimized for the Dreamcast controller. You could tilt the analog stick slightly to make Sonic walk slowly, and he would walk faster the farther you pushed the analog stick. While this is still present in the ports, the analog sensitivity is a bit screwed (in the PC port at least), and depending on the controller the range between slow walking and running at full speed can be very short. In the PC version it’s fixable with SonicFreak94’s Input Mod. While this isn’t a major issue, it might affect people’s opinion on controls in this game because it messes up the already floaty controls of the original.

Some people say it’s impossible to run in a straight line in the Dreamcast game because it constantly tilts the analog controls to the left or right. This is a common myth caused by emulation inaccuracies – it doesn’t happen on actual hardware (but see the note below regarding third-party controllers). The reason this happens on emulators is that the Dreamcast controller has a non-standard deadzone that the Dreamcast version of the game compensates for. More information here. A less common complaint about the Dreamcast version is that you can move at insane speeds by steering the analog stick diagonally while jumping – this is also caused by the emulation issue mentioned above or by using third-party controllers.

Let me just finally clear up the analog sensitivity issue and hopefully dispel the “impossible to run in a straight line on DC” myth for good. Here is what the original Dreamcast controller’s deadzone looks like (I’m using an adapter to connect Dreamcast controllers to PC via USB):

Notice how it’s very easy to slip to the side slightly while holding up or down. The Dreamcast controller’s analog stick is very sensitive to allow precise movement. Another characteristic trait of the Dreamcast controller is a diagonal movement limit – so when you rotate the stick, the shape the cursor follows is a circle rather than a square. Both of the above things are taken into account in Dreamcast versions of SA1 and SA2. These games expect some analog “noise” that comes from the player holding the stick in a straight direction, and compensate for it so that you can run in a straight line when holding the stick all the way up/down while still having the benefits of more precise movement at slower speeds.

Now here’s what a third-party controller’s deadzone is like:

The above video demonstrates input from another Dreamcast controller that looks identical to the original, but this one was made by a third party. This is also how most cheaper controllers behave on PC. The deadzone in this controller is more stiff, which removes the jittering “noise” while holding the stick in a straight direction, and there is no “rounded” limit to diagonal axes like in the original controller. The first deadzone difference makes Sonic unable to run in a straight line in SA1 and SA2, and the second difference makes it possible to travel at much higher speed in SA1 while jumping and holding down the analog stick diagonally.

Now let me reiterate. The reason people are getting all those control issues in the Dreamcast version of the game is because they have either of the following:

1. An emulated version of the game on PC, which is still optimized for the original Dreamcast controller rather than third-party controllers or the keyboard. The emulators don’t remove the game’s compensation for analog “noise” of the original controller, and they don’t add a limit for diagonal axes in SA1 and SA2, which the original controller had. If you connect the original Dreamcast controller to your PC, the problems go away.

2. A third-party Dreamcast controller that has a less sensitive deadzone and/or no diagonal axis limit, which causes problems in the Dreamcast game similar to those experienced on an emulator with a keyboard/non-Dreamcast controller.

To sum it up, these problems do NOT happen when original hardware is used. However, they MAY happen on emulators or on a real Dreamcast when using third-party Dreamcast controllers.

The true reasons behind the infamous “sewer glitch”

One of the fake “issues” that gets brought up often is the glitch that happens in Sonic’s story after obtaining the Light Speed Shoes and makes him unable to get out of the sewers. Like the controls issue, it can happen on a real Dreamcast. There are workarounds but the issue is generally quite frustrating. However, it has nothing to do with the Dreamcast version of the game per se.

The “Light Speed Dash sewer glitch” happens in two scenarios:
1. Emulation bug involving floating point values
According to inolen, the developer of the redream emulator, there is a CPU emulation issue that can cause this glitch on Dreamcast emulators. The latest version of Demul isn’t affected. The glitch can happen on NullDC, reicast and redream (it may have been fixed in redream as of October 2018).

2. Pirated rips of the game with incorrectly patched binaries
The original Dreamcast version of SA1 came on a GD-ROM disc, which could hold up to 1GB of data. Pirates have exploited the Dreamcast’s ability to read ordinary CD-ROM discs and made “selfboot” packages that can be burned to ordinary CD-Rs and played on the Dreamcast. Such packages also removed regional limitations so you could play the game from any region on any Dreamcast console. Preparing a selfboot package involves hacking the original binary files to allow the game to boot from a CD-R. Many older scene rips of Sonic Adventure have a patched 1st_read.bin that causes the infamous sewer glitch.

Because the issue is caused by two completely different factors, it is reproducible on emulators and on a real Dreamcast, which made a lot of people assume it’s an issue with the original game. To avoid the issue, just make sure to do the following:

  • If you’re playing the game on a real Dreamcast, use the original GD-ROM version of the game or a good rip, such as the DCRES rip of Sonic Adventure International.
  • If you’re playing the game on a Dreamcast emulator,
    1) Use the latest version of Demul and
    2) Use GDI rips (which are made from original GD-ROMs), not CDI rips meant for burning.

Transparency issues

All versions of SADX suffer from problems with rendering transparent models, which play a major role in visual downgrades. The original game took advantage of SEGA Dreamcast’s hardware features that were impossible to replicate on the Gamecube and other platforms. When the game was being ported to other platforms, the developers ran into numerous transparency-related problems with ingame assets. Some of such problems were fixed, but in the majority of cases the problematic assets were redesigned, usually without much care for quality or style of the original game. Let’s discuss the transparency issues in general, have a look at some specific problems and see how they could’ve been fixed.

In many ways, the Dreamcast was a console ahead of its time. One of the Dreamcast’s unique features was its PowerVR GPU. It was equipped with a hardware feature called order-independent transparency (OIT). No console before or after the Dreamcast ever had that feature built in on the hardware level, and it took many years until mainstream GPUs became capable of dealing with order-independent transparency.

Why is this significant? Traditionally, in 3D graphics rendering transparent objects is a pretty complex problem. To properly display transparent models together with non-transparent models, the polygons in a 3D scene have to be rendered in a specific order. Transparent polygons have to be rendered after opaque polygons in back to front (furthest to nearest) order to ensure the transparent blending operations are performed correctly. The framebuffer is the “canvas” on which the polygons are “painted”. The order is important because once something’s been “painted” onto the framebuffer, you cannot simply put something behind a transparent object that’s already there.

In complex scenes with many transparent objects and moving camera this can become a problem because the engine needs to tell what is visible from the current camera angle, whether the visible polygons have transparency or not, and how close they are to the camera, all of which would influence their draw order. On top of that, the composition of each model should ensure that the transparent polygons are processed after the opaque polygons, not before. Even modern games struggle with transparent things sometimes.

With order-independent transparency the above issues are irrelevant. The polygons can be processed in any order, and transparent and non-transparent polygons are sorted automatically by the Dreamcast’s GPU. In the case of SA1, up to 32 layers are sorted per pixel using 32×32 tiles, while other games, such as Omikron: The Nomad Soul, require 64 layers to look correct (according to MetalliC, the developer of Demul, the Dreamcast can sort up to 256 layers). This allowed the developers of Dreamcast games to create complex scenes involving transparent things without worrying about draw order. It was also unnecessary to have a strict model hierarchy of transparent and non-transparent polygons. Sonic Adventure is one of such games where the ingame assets are mixing transparent and opaque polygons without any consistency.

When the game was being ported to the Gamecube, the benefits of order-independent transparency were no longer there, and the developers ran into numerous problems involving transparent models. They tried to address them in two ways:

1. A draw queue system was set up to tell the game which models should be rendered in what order. While technically not bad for a game of that generation, the draw queue system doesn’t always work right in this game because of code bugs, and, judging by the disassembled code, the developers themselves didn’t know very well how to use it. The most common issue with the draw queue system is transparent objects disappearing when you move the camera. This happens pretty often throughout the game, check out Twinkle Park or Hot Shelter for examples.

Sometimes the draw queue can’t handle transparent things because of engine limitations. For example, look at the aquariums in Hot Shelter Act 1:

Dreamcast
PC

The water behind the green glass is invisible in SADX, but it’s still there – here’s a part of it that manages to clip through the glass. This scene requires the water to be rendered first so that the green glass can be rendered on top of it. The reason it doesn’t render in SADX is that the water here is an interactive object (SET object), whereas the green glass is a level piece, and the game always renders objects after level pieces. This confuses the draw queue system and makes all transparent things behind the green glass disappear.

2. Alpha rejection was an additional measure to hide transparency problems or make them look less terrible. For textures with an alpha channel, the game only displays the pixels whose transparency (alpha) value is within a certain range. This allows some models with a grid-like transparent pattern (fences in Speed Highway and Hot Shelter, paths in Windy Valley) to look acceptable even though the game is still struggling with rendering them. Here are some examples of alpha rejection:

This doesn’t look too pretty, but at least it helps a bit. However, the problem with alpha rejection in SADX is that it also breaks a lot of completely unrelated special effects. In Perfect Chaos, alpha rejection causes special effects such as waterfall splashes and mist to flicker or disappear. Check out the Bosses section for a comparison. Also, all particle effects now have ugly outlines that makes them look low-res. Water splashes, dust, fire, explosions – all of these look lower quality than they are because of this feature. Here’s an example from Lost World:

Dreamcast
Gamecube

Even with the above workarounds in place, the game still has a huge amount of transparency issues. There is no solid proof for this, but I’m inclined to believe that the majority of “stylistic” changes in SADX were made because the port had problems displaying the original assets correctly. I think so because I’ve imported Dreamcast levels into SADX myself and found out that almost all levels that look different in SADX had transparency issues with their original Dreamcast designs.

Here’s a typical SADX redesign. This roof had a triangle-shaped pattern in the Dreamcast version. In SADX the pattern was removed and the roof was made solid:

Dreamcast
PC

This was likely done because the triangle pattern is a square texture with an alpha channel, which had rendering problems in SADX. Here’s a screenshot from the “Preview” prototype where this area is still using Dreamcast graphics:

In fact, you can still see issues with textures like that in the final version at some camera angles if you try hard enough:

There appears to be a strong correlation between the areas that were redesigned and the areas that had rendering issues in the port with their original designs, which is why I believe the majority of those redesigns were done to get rid of transparency problems. As you can see, even the replacement assets don’t always work well.
NOTE! The above point is speculation on my part. My opinion is based on my experience with both games. However, the only way to know why the assets were redesigned is to ask the people involved with the ports, which is unlikely to happen anytime soon. There are other possible reasons for SADX redesigns, which will be discussed in a separate section on this blog in the future.

Even within the engine limitations, most transparency issues in SADX are fixable by rearranging the models involved, which is usually just moving around a couple of lines in code. Let me illustrate a typical transparency problem in SADX and how it can be fixed within the limits of SADX engine:

Here you can see a shop roof that has to be rendered together with its surroundings. Let’s describe all the meshes involved in this scene:

  • 1 – roof top (opaque)
  • 2 – roof side (opaque)
  • 3 – roof top decoration (transparent)
  • 4 – wall
  • 5 – window reflection (transparent)

To render this properly on platforms other than the Dreamcast, we have to arrange these meshes in the correct order, which would be 4, 1, 2, 5, 3. We render the non-transparent pieces first, starting with the wall, and then we render the transparent parts, finishing with the one that should be layered on top of the previous one. In order to render these assets like that, we have to make sure the level pieces are arranged in this particular order. However, in the Dreamcast level the order could be anything, which is why there are issues when the original level is imported as-is. There are cases when this gets complicated, but for the most part rearranging the models is quite easy. However, instead of rearranging the problematic models (which probably would’ve taken less time and effort), the developers decided to redesign those areas with new textures and models. The redesigned assets sometimes fail at conveying the atmosphere of the original game. Quite often they lack the variety or special effects of the original, or have lower quality textures. There are also cases where the developers didn’t redesign or fix the models that still have transparency issues. Almost every level in SADX has problems related to transparency. You can read more on level-specific problems by using the top menu.

I resolved the majority of transparency issues with Dreamcast assets in my mods by sorting the models manually. Sometimes I also hooked the game’s queued model system to set an arbitrary depth value to make models render in a specific order. Although not everything is fixable this way, I think my mods demonstrate that making a faithful conversion of SA1 assets was possible in the PC port at the very least.

Sound and music quality downgrades

As unfortunate as it is, sound and music quality has suffered almost as badly as textures and lighting in SADX. Let’s have a look at the sound problems plaguing the ports.

First of all, I’m going to be talking primarily about the PC version and later ports. This is because the Gamecube version’s sound format hasn’t been reverse engineered yet to allow direct sound quality comparions (although we can make some rough estimations). If you want to read about sound downgrades in the Gamecube version, skip forward to the part where I talk about sound bugs and missing sounds.

There are several types of sound issues in SADX, and they are specific to different ports. Here’s a list of issues and the ports affected by them:

  • The music no longer loops – 2004 PC port
  • Lower quality voice clips – 2004 PC port (all clips), Steam and nextgen console ports (only some clips)
  • Lag/stutter caused by the voice file format – 2004 PC port
  • Lower quality sound effects – 2004 PC port, Steam and nextgen console ports
  • Missing processing effects on some sounds – all ports
  • Sounds being cut off, looping incorrectly or playing too early/too late – all ports
  • Some sounds are missing – all ports
  • Wrong soundbanks are loaded, causing wrong sounds to play – all ports
  • Sound volume problems: some or all sounds are too quiet (PC 2004 port) or too loud (Steam/nextgen console ports)
  • Sound playback problems (sounds/voice clips playing in lower quality than the actual sound/voice files) – Steam and nextgen console ports

Let’s talk about the music first. The Gamecube, Steam and nextgen console ports use ADX music files that are the same as in the Dreamcast version. On the Dreamcast, some music tracks were downsampled in the versions of SA1 that contained both English and Japanese audio clips – this downsampling was undone for the GameCube version, so unless you own the Japanese version of SA1 this is technically an upgrade (however, the Steam and nextgen console ports fail to take advantage of it and end up sounding worse, which I will discuss later).

For the 2004 PC port, ADX music files were converted into WMA files. The main problem with the WMA format is lack of looping, which means the music in the PC port fades out and restarts at some point, while in other versions of the game it loops seamlessly. This isn’t a major issue, especially because the Mod Loader has brought back ADX music support.

However, there are other problems with the WMA format. Character voice clips were also converted into WMA for the 2004 PC port. This would’ve been fine because the voice clips don’t need loop points, but the conversion reduced the quality of the resulting voice clips. Here’s a voice clip from both versions with audible quality difference despite the WMA one using a higher sampling rate and stereo sound:

Dreamcast:

PC 2004:

A well-known problem with the 2004 PC port is the stutter that happens during the kart race when you hit the jump panels and Sonic says “woohoo!”. When this happens, the game pauses for a brief moment. This has something to do with the voice clips being in the WMA format because it doesn’t happen in the ports that use ADX audio. Thanks to the Mod Loader you can fix the problem in the 2004 PC port by installing a mod that replaces all WMA voice clips with ADX voice clips.

Although the Steam/Dreamcast Collection port goes back to ADX voice clips, which are the same as on the Dreamcast/Gamecube for the most part, there are several voice clips that were edited. Those edited clips are lower quality than the original voice clips. There are only 9 English voice clips and 11 Japanese voice clips that are different from the Dreamcast version. Most of the edited voice clips have to do with the options menu, where the “Options” part was cut out for some reason. You can hear that the edited voice clip sounds a bit muffled:

Dreamcast:

Steam:

Now let’s talk about reduced sound quality. The easiest way to illustrate the reduction of sound quality is to compare jump and ring loss sounds across different versions. Here’s the jump sound:

Dreamcast:

PC 2004:

And here’s the ring loss sound:

Dreamcast:

PC 2004:

Steam:

I think the sounds speak for themselves, but by sound quality I mean not only technical things such as sampling rate, but also volume, processing effects and looping of various sounds. The biggest problem with SADX sounds is that they are too quiet. In the Dreamcast version, almost every Action Stage and Adventure Field has some kind of a background noise that is loud enough to be audible without washing out the music. Those sounds are still present in SADX, but they are so quiet a lot of people think they are missing. One of the most illustrative examples is the machinery noise in Final Egg Act 1, which you are supposed to hear right from the start, but it’s barely audible in SADX. The sea in Station Square hotel is also barely audible in SADX. Another example is the ticking sound of the clock in Speed Highway Act 3, which is there but due to a combination of low volume and SADX’s positional audio weirdness it’s rarely heard ingame.

Some sounds have missing digital processing effects. For example, if you watch the cutscene before the Chaos 0 fight, you can hear the sound of bullets falling on the ground after the police shoot Chaos. In the Dreamcast version, that sound had a reverb effect that created the impression of multiple bullets falling, but in SADX it sounds like a single bullet. A similar problem happens with Zero’s chest thumping sound, which is barely audible in SADX because of the missing reverb effect.

There are several sound bugs in the ports that cause sounds to play too early or too late, or not play at all. The game’s sound engine doesn’t always work well with the increased framerate of the port, which causes some sounds to get cut off or loop incorrectly. A good example of that is the looping background engine noise of the Egg Hornet, which plays fine at 30 FPS, but cuts off at 60 FPS.

As for the sounds that play too early, most of the cutscenes involving the Tornado crashing or landing have sound timing problems. For example, in the cutscene where the Tornado 2 lands on the Egg Carrier, the metal screeching sound plays before the Tornado actually touches the Egg Carrier. This doesn’t happen in the Dreamcast version. The Dreamcast version also has a few sound problems like that (for example, the sound of the Tornado crashing in Tails’ opening cutscene plays too early and gets cut off), but SADX has many more.

The ports have code bugs in the positional audio system that cause some sounds to never play ingame. In addition, some sounds were deliberately removed or disabled. It’s difficult to talk about all of them in detail, but here’s a list of SADX sound bugs that weren’t there in the Dreamcast version (this isn’t a complete list, also some of these were reported to me on Sonic Retro forums before I started working on the Sound Overhaul mod):

  • The spindash sound gets cut off if you have the Light Speed Dash upgrade.
  • In the cutscene where Knuckles attacks Sonic, Sonic says “Whoah!” before jumping backwards. It isn’t heard in SADX because Sonic’s soundbank isn’t loaded by that cutscene.
  • A thud noise is missing when Sonic (or Tails) and Knuckles run into each other and drop the Chaos emeralds before Chaos 4 emerges.
  • The water splashes made by Chaos 4 are muffled by another sound that was mistakenly set to stereo, which interferes with the positional audio system.
  • A skid noise when Beta backs up just before his first boss battle is missing.
  • A foreboding noise when ZERO’s shadow casts over Amy in the cutscene after Twinkle Park is missing.
  • The cutscenes in Amy and Gamma’s story where Gamma lets Amy escape load the wrong soundbank, which causes the cutscenes to either be silent or play random unrelated sounds.
  • Bush rustling in the Angel Island hub no longer loops, although the sound is still there.
  • The rings that NiGHTS takes you through in Casinopolis’ NiGHTS pinball game no longer make a sound as you travel through them.
  • The bombs dropped by the airplanes in Ice Cap Act 3 no longer make a whistling sound as they fall down, and their explosions are silent.
  • The sound of collecting rings is in mono instead of stereo – this is because the sound file itself was converted to stereo. The game alternates between the left and right channel when playing this sound, which requires it to be in mono.
  • In Sky Deck Act 2, Eggman’s announcements when the ship changes altitude (“Descending into the clouds; slow the ship down!” or “Go up! Full speed ahead!”) are no longer heard because they were removed from the Sky Deck soundbank. The game still plays them if the sounds are put back into the soundbank.
  • The ambient machinery noise at the Mystic Ruins Final Egg base is missing – the noise sound was replaced by a single beep, and the function to play the noise was disabled in code, probably because the developers realized that the replacement was annoying. It’s unclear why the original sound was replaced.
  • Hot Shelter loads the wrong enemy soundbank, which makes badniks like the Egg Keepers play the sound of the ocean.

The Chao soundbanks were replaced in SADX because the Chao system itself was changed to be more like SA2B. We talk more about Chao-related downgrades on the Chao Gardens page, so here let’s focus on the sounds. It’s hard to compare sounds directly because the soundbanks are very different between SA1 and SADX. Nevertheless I found some identical sounds that we can compare. Which one do you think sounds better?

Dreamcast:

PC 2004:

Finally, let’s discuss the ADX playback downgrade in the Steam and Dreamcast Collection ports. Sound quality in the 2010 ports is undeniably the worst among all versions of the game. Unlike SADX Gamecube and PC 2004, these ports have the opposite problem with sound volume. The background noises drown out almost everything but the music (example: try playing Casino Act 1, where even the music is barely audible because of the gushing water noise). There’s also something noticeably wrong about sound quality. I originally assumed those problems came from the sounds themselves, but apparently it’s a bit more interesting.

The 2004 PC port uses WAV sound effects stored in DAT soundbanks, while the 2010 version uses the same soundbank format but with ADX sounds instead. The soundbanks themselves are identical between the Steam, PSN and X360 versions. When I extracted the soundbanks and tried playing some of those ADX files, I noticed that they sounded better in the audio player than in the game. Why does the game play them like that? I can’t say for sure but here is a possible explanation:

ADX is a closed-source lossy ADPCM-like format, which uses a prediction-based algorithm for decompression. Perhaps there was a precision error either in the game’s programming or with how the sounds were originally encoded, and they ended up sounding inaccurate ingame. Maybe they were encoded with one version of the algorithm, but the game uses another. I’m getting similar results with some tools.

Here’s a sound from the E_0001 soundbank that plays when Chaos 0 is defeated. This is how it sounds if the ADX file is decoded with an old tool called adx2wav. It sounds like that ingame too:

And this is how it sounds when decoded with vgmstream:

The same sound from the 2004 port for comparison:

To test my guess, I set up scripts to convert all soundbanks from the Steam version into the format supported by the 2004 PC port – these scripts are now used in my mod installer. The quality of sound effects in the Steam version is about the same as in the 2004 PC port, though many sound issues from the 2004 port remain unresolved. Unfortunately the Steam and nextgen console ports of SADX fail to play these sounds in their original quality.

To fix sound problems in the PC version of SADX, I went through all sounds in the Dreamcast version (except Chao-related soundbanks) and converted them into a format supported by the 2004 PC port with proper looping where necessary. I’ve also adjusted the volume of background noises, added processing effects to several sounds and restored many missing sounds. The majority of sound issues mentioned in the blog post is now fixed in the 2004 PC port with the Sound Overhaul 2 mod. To learn more about mods for the PC version, visit the “Fixing the PC version of SADX” section on this blog.

Lighting downgrades

There’s no doubt that lighting was the biggest downgrade in the Dreamcast-Gamecube conversion of Sonic Adventure. It’s easily the most noticeable downgrade in the entire game, and the most serious from a technical standpoint. Let’s compare lighting systems in SA1 and SADX and see how they perform against each other. Thanks to reverse engineering we know quite a bit on how they work.

The Dreamcast version of the game has a pretty interesting lighting system (referred to internally as “LANTERN”) that uses color palettes. The lighting information for each level is stored in a pair of files: the PL file (PL*.BIN) contains the palettes, and the SL file (SL*.bin) contains light direction and some miscellaneous information. Let’s talk about the PL files first. Here is a typical set of palettes found in a PL file (Twinkle Park Act 1):

The Dreamcast version’s lighting system uses a formula to calculate the “brightness index” of each vertex (point) in the scene, which is used to select colors in the palette. Several factors, such as the model’s normals and light direction (stored in the SL file) affect brightness index calculation. If we visualized brightness indices (from white being maximum brightness to black being completely unlit), it would look something like this:

Now look at the palette list again. The left row is diffuse palettes. Diffuse palettes contain colors that the original (fullbright) texture gets multiplied by, like using Photoshop’s “Multiply” blending mode. Specular colors are added on top of the result of the multiplication, in a similar way Photoshop’s “Add” blending mode works. Because it’s additive, specular lighting creates highlights. The “gloss” on Sonic and other characters is an example of specular lighting.

Each palette consists of 256 colors. The color the texture gets multiplied by (or the color that gets added as a specular color) has the same index in the palette as the brightness index of the vertex. So the “brightest” vertex would get the first (0) color in the palettes, and the “darkest” vertex would get the last (255).

It’s a pretty neat system that allows to use a wide range of colors to create vivid, original environments. But the system used in the Dreamcast version is even more versatile than that, because it allows different kinds of models (level pieces, characters etc.) to use different palettes, and even within the same model different meshes can alternate between two specular palettes using material flags. For example, the screenshot below was taken from the Dreamcast version where all palettes were replaced with different solid colors. You can see the complexity of color combinations that comes from using many diffuse and specular palettes at the same time:

So, how does the game know which pair of palettes to apply to a given model? There are several main palette application rules, as well as some exceptions. To illustrate the full range, we need to look at another PL file. Here’s a palette list from Gamma’s Hot Shelter:

When each model is rendered in the game, there is usually a function call that sets the “light type”. A light type corresponds to a certain pair of palettes. For example, Diffuse 0 is always applied to level pieces and objects. Specular 0 is applied to level pieces and objects when their meshes have the “ignore specular” material flag set to on. If it’s off, Specular 1 is used instead. The above rule also applies to all models that set the light type to 0.

Diffuse 1 and Diffuse 3 are never used in the Dreamcast version.

Diffuse 2 is the main diffuse palette used by playable characters and NPCs. In some rare cases it can be used by objects (such as floating meteors in Twinkle Park Act 1 or Chaos Emeralds in cutscenes) if they specifically set this light type. Specular 2 and 3 are used depending on whether the mesh has the “ignore specular” material flag. For example, Gamma’s model uses mostly Specular 3, although some of his body parts use Specular 2. Here’s an example of what usage of three different palettes can do (well, it’s actually two palettes since the third one is just black in this example, but still):

By the way, did you ever notice that Gamma’s eyes and head base are lit up in the Dreamcast version, but not in any of the ports? This is because the “ignore light” material flags were removed from Gamma’s model. For the same reason Big’s eyes no longer glow in the dark. This is a simple material flag change, however, and it works the same way in both lighting systems.

Diffuse 4 is a special palette. It is used by the fire effect in the Mystic Ruins Past, as well as some bosses. For example, the models for Chaos 2, Chaos 6 and Perfect Chaos all use Diffuse 4 and Specular 5. These palettes are used to accentuate the bosses and give them lighting that matches the environment. This is what Chaos 6 looks like with and without the diffuse palette:

Diffuse palette
No palette

But that’s not all! In some cases the game switches between different PL/SL files in real time. For example, in Sky Deck Acts 1 and 2 the game toggles between two different sets of palettes when the Egg Carrier changes altitude. This affects not just the level, but also the characters:

In Mystic Ruins Past the game also alternates between palettes, but within the same file:

The level and objects that would normally use Diffuse and Specular 0 have a fade effect that blends between Diffuse/Specular 4 and 5, creating the effect demonstrated below. The effect is missing in the Gamecube version:

Dreamcast
Gamecube

Now that we’ve discussed the basic outline of the lighting system used in the Dreamcast version, let’s compare it with the Gamecube version. The palette lighting system was completely removed in the ports. Thanks to the “SADX Preview” prototype that was leaked several years ago we can confirm that the palette lighting system was functional on the Gamecube sometime earlier, but it was removed from the final version. A more traditional, less sophisticated lighting system (I’m going to refer to it as the “Stage Lights” system) was set up in its place. According to the data found in SADX Preview (which allows to toggle between lighting systems), the new lighting system allows to use the following parameters:

    • Light number – apparently up to 4 lights can be active at the same time, but the game seldom uses more than 1 or 2
    • Diffuse brightness – affects the overall brightness of the light
    • Light color (diffuse)
    • Ambient color – a separate color that is added on top of the diffuse color. Unlike specular, this isn’t a separate additive effect so it’s effectively the same as making the overall (diffuse) light color brighter
    • Light direction

This system clearly doesn’t allow as much creative freedom as 256 individual colors for each brightness index in the Dreamcast version. There is also no support for specular lighting, which means the level pieces can no longer have specular highlights/gloss. However, even with such a system in place it would’ve been possible to create environments that looked somewhat decent. After all, not all levels in the Dreamcast version use crazy multi-color light transitions or a lot of specular highlights. You can find some areas that look okay-ish in SADX Mystic Ruins, Hot Shelter and Lost World. Emerald Coast and Windy Valley also look alright because the original palettes for them were simple white-to-black gradients, which the new system can imitate easily. Other stages, such as Ice Cap, Red Mountain or Final Egg, feature much less vibrant environments than the Dreamcast version.

The new lighting system is also broken in the PC version of the game. If you compare the screenshots from each version side by side (which you can do by going to individual level comparisons using the top menu), you can see how the PC version washes out the lighting even further and makes everything too bright. For example, in the Mystic Ruins it’s hard to tell what time of day it is without looking at the sky because the ground is lit up at all times. Station Square also looks almost the same during day and night. This problem persists in all later ports of the game, including the nextgen console ports.

The downgrade described above happened with level lighting, but character and object lighting is different. The Gamecube version in particular has a pretty versatile system for character lighting. I believe this could have been the same system that was originally used to generate palettes for the Dreamcast version of the game. Again, looking at the Preview prototype is helpful with understanding how it works:

In the screenshot above you can see SADX Preview’s debug menu for character lighting. It generates two palettes (diffuse and specular, just like in the Dreamcast version) using a formula that takes in the following parameters:

  • Color1 color and power – diffuse palette
  • Color2 color and power – diffuse palette
  • Ambient color – added on top of the diffuse palette (multiply)
  • Specular1 color and power – specular palette
  • Specular2 color and power – specular palette
  • Light direction

(There’s also a “diffuse” parameter that doesn’t seem to do anything)

Using the above parameters it’s possible to create a lot of different palette combinations, and it would’ve been quite easy to imitate the color variety of the Dreamcast version using the same formula. The prototype even has a menu that is supposedly meant to load lighting information from a file. It could be that the developers were trying to load the Dreamcast’s PL files and recreate the gradients stored in them for use with the formula. Or perhaps the menu comes from an older build, which was used to generate the PL files. We don’t know what exactly the menu was used for, but the PL and SL files from the Dreamcast version can still be found on the retail game’s disk, and they were even byteswapped for compatibility with the Gamecube’s Big Endian format. It’s possible to activate them in the Preview prototype, but they are never used by the final version.

Although the character lighting system described above is a lot more flexible than the level lighting system, for some reason its potential was largely unused. Only in a few stages do we see Sonic and other characters colored differently, and in the majority of areas the lighting on Sonic barely changes at all. Since I have reverse engineered the palette generation formula, I was also able to convert SADX character lighting parameters into palettes. Here’s what those palettes look like in comparison with the Dreamcast version:

You can see how the Dreamcast version’s palettes are much richer, with more gradations and color variety than the Gamecube version. It was entirely possible to recreate the Dreamcast version’s character lighting in SADX, but the potential was hardly used at all. Most levels in SADX use simple white-to-black gradients for character lighting, sometimes with minor specular tints, which would’ve been a good start, but only a handful of levels in SADX use specular colors different from white and grey.

Another problem with the Gamecube version’s character/object lighting is that it often sets the specular values so high the models receive strong white gloss that can even obscure the details. For example, this is what happens to the Spinner enemies in Sky Deck:

The white eyes are caused by an excessive amount of specular lighting. This is what these enemies look like in the Dreamcast version:

In addition to the above, the PC version has other major problems with character lighting. Half of character lighting values are never used in the PC version – only Ambient and Specular 1 colors are applied to the model, whereas Color 1, Color 2 and Specular 2 components of the palettes are never used. This makes it technically impossible to have any kind of complex gradients for character lighting in the PC version. Perhaps the developers didn’t implement support for those additional values because the Gamecube almost never used them anyway. The PC version also has a problem with excessive specular. The game adds a directional specular light regardless of the model’s material flags. Although the amount of specular lighting can be controlled, in SADX it’s inflated to extremely high levels, especially in the PC version, which results in the infamous problem with the characters being “too shiny”. Interestingly the 2010 port (Dreamcast Collection/Steam) uses a shader for character lighting, and the lighting on characters and objects looks a lot closer to what it looked like on the Gamecube. This is one of the few advantages the Steam version has over the 2004 PC port, which is otherwise far superior (downgrades mentioned on this blog notwithstanding).

To compensate for the removal of palette lighting, the Gamecube version uses three approaches to creating stage lighting:

  • The Stage Lights system that we’ve discussed above
  • Semi-transparent models that are overlayed on top of other meshes to create an illusion of a shadow
  • Fake lighting using baked-in vertex colors

Out of these three, only Stage Lights are “dynamic”, i.e. not attached to the level model. With the Dreamcast version, the same level could have completely different lighting with a simple swap of PL/SL files. The SADX counterpart of that is the Stage Lights system, which is used for such things as daytime changes in Adventure Fields. However, the other two types of lighting are baked into the level model itself and stay the same regardless of the time of day. The semi-transparent models (which look like this) are barely used in the game in stages other than Station Square and Emerald Coast, and there’s little to discuss about them – they’re just semi-transparent shapes overlayed on top of some level pieces. Vertex colors, however, are a bit more interesting.

Vertex colors are a relatively ancient technique used in games to enhance color variety without using a different texture. Vertex colors are color information stored for each vertex (point) in a model, which can be used for various things, such as transparency or ambient occlusion. Palette lighting in the original game is also done using vertex colors.

The main advantage of the Dreamcast version is the “dynamic” nature of vertex colors, which can change depending on light direction, the model’s material flags, camera position, the colors in the palette and the light type. In SADX, however, this kind of lighting is faked because the vertex colors are static. Once a model has vertex colors baked in, they will never change no matter what happens to the environment. This may be sufficient for most Action Stages because they don’t need to change, but problems arise when vertex colors are used on objects or in areas where lighting changes significantly, for example in Sky Deck or in the Past cutscenes. With palette lighting it’s possible to switch to a separate palette to create a completely different look without touching the level’s model. But SADX vertex colors always stay the same.

There have been arguments that the SADX levels are inherently “better” because they have “beautiful” vertex colors baked in, while the SA1 levels don’t have built-in vertex colors. While the point about SA1 levels missing vertex colors is correct, the actual argument got it entirely backwards. The levels in SA1 are meant to work with the Lantern lighting system. Obviously they don’t have static vertex colors because vertex colors are generated dynamically by the palette lighting system. In SADX, however, the static vertex colors were added to camouflage the removal of palette lighting. Moreover, calling the vertex colors in SADX levels “beautiful” would be a bit of a stretch as they are nowhere near as vibrant and diverse as the original game’s lighting – see each level’s page for a closer comparison. There’s one potential advantage of having the vertex colors baked in – the ability to customize lighting per vertex. From a technical standpoint this allows more control over lighting than the palette-based system, and SADX does have some cool additions the original game doesn’t have, such as the lights cast on the ground by lamp posts in Speed Highway. However, most of the time the developers didn’t bother to add this kind of detail, and the original’s lighting looks vastly superior as a result.

Realtime lighting effects aren’t possible with built-in vertex colors. Note how the lighting changes on all level pieces on the Dreamcast, while the Gamecube version only changes the skybox:

Dreamcast
Gamecube

The problem with vertex colors being static causes many lighting details to disappear in SADX. For example, the lighting on such objects as rings, or boxes in Red Mountain, or enemies, reacts to the environment around them in the original game. So if you saw a box in Red Mountain Act 1, it would have Act 1’s palette, but in Act 2 the same box would have Act 2’s palette, which gave it a red glow. With a system like that no longer in place, vertex colors stay the same regardless of which level it is. It would’ve been possible to palettize such objects using the character/object lighting system in SADX to give them more vibrant lighting, but other than excessive specular glow in some cases the SADX object/character lighting system doesn’t bring back the original game’s vibrancy. In the comparison below the boxes use the same model, but their lighting reacts to the environment much more prominently in the Dreamcast version due to the use of two palettes (diffuse + specular), while SADX relies almost exclusively on ambient lighting:

Dreamcast
Gamecube

To make matters worse, the PC version (and all later versions based on it) ignores built-in vertex colors for all objects that are not part of the level model. For example, look at one of the pinball entrances in Casinopolis: it has green vertex colors in the Gamecube version, which are missing in the PC version (Left: Gamecube, Right: PC):

Gamecube
PC

The model in the PC version still has vertex colors, but they aren’t applied because the functions that render object models in the PC version ignore vertex colors. This issue is persistent across all later ports as well, making the Gamecube version the only version that displays those colors properly.

Like with texture quality, this creates a situation where the most accessible versions of the game have much worse lighting than the Gamecube version, which was already inferior to the Dreamcast version. Thankfully the Dreamcast version’s lighting engine was almost completely recreated in the 2004 PC port by SonicFreak94. Visit the “Fixing the PC version of SADX” section for more information on how to install the mods and experience the original game’s lighting on PC!

You can compare the lighting in individual Action Stages and Adventure Fields by going to level comparison pages using the top menu.

Texture quality downgrades

When Sonic Adventure was redesigned with the “DX” branding, some of its Action Stages and Adventure Fields received new textures. In some cases those textures are higher resolution than the Dreamcast version, in other cases they aren’t. Some offer more variety than the original game, most of them don’t. In some cases the textures are completely new, in other cases the new textures are recycled or slightly edited Dreamcast textures, sometimes in lower resolution (Final Egg) or with reduced saturation (Ice Cap). You can read more about textures used in a particular level on each level’s page. This page is about texture quality in general. It examines the problems with texture quality in SADX Gamecube and PC and explains why the quality reduction happened.

Textures that weren’t redrawn for SADX (which make up the majority of textures in the game) were recompressed each time the game was ported to a platform that used a different texture format. The Dreamcast’s native PVR format is rather limited and allows only a couple of texture formats. The Gamecube’s GVR format is more flexible than PVR, and allows several more texture formats. Both formats are lossy (unlike BMP or PNG for example), which means some source information will be lost when a texture is saved in a format like that. The developers of the original game handled PVR limitations with great care (or they just had good conversion tools), and the Dreamcast version has pretty sharp textures for an old and limited format like PVR. Normally there would be no issue with converting a PVR texture into some other format. In SADX, however, there is a visible quality loss. Let’s see why.

Here are the most common PVR texture formats used in the Dreamcast version:

  • RGB565 – an opaque texture where each pixel uses 5 bits for red and blue and 6 bits for green.
  • ARGB1555 – a transparent texture where each pixel uses 1 bit (on/off) for transparency and 5 bits for red, green and blue channels.
  • ARGB4444 – a transparent texture that uses 4 bits for red, green, blue and transparency.

The GVR format used in the Gamecube version supports additional texture formats, such as ARGB8888 (8 bits for each color and transparency – same as in lossless bitmaps), as well as DXT1 compression. However, when the Dreamcast textures were converted into GVR, the source format (for example, RGB565) was neglected, and the destination format didn’t accommodate for all the color information that was present in the original texture (for example, instead of 5 bits for each color, only 4 were used). As a result, some information was lost when the textures were converted, and most textures in the Gamecube version are lower quality. The recompression happened again in the PC version, which switched the textures back to PVRs. Instead of using the original PVR textures from the Dreamcast version, the developers decided to recompress the already lossy Gamecube textures back into PVR, making the same mistake for the second time. It’s quite likely that the developers of the port didn’t assess texture quality after conversion. On the retail Gamecube disk of Sonic Adventure 2: Battle there is a leftover script that was used to convert the Dreamcast PVM texture archives into Gamecube GVM archives. It’s highly probable that something similar was used for each port of SADX.

It must be said, however, that there are at least several textures in the Gamecube version of SADX that appear to be higher quality than the Dreamcast version. These textures are sometimes found in levels that were redesigned in SADX. At the moment there are only six textures known in the entire game that have better compression in the Gamecube version. One texture is found in the Mystic Ruins main area (see below), the rest are in the first segment of Final Egg.

(Thanks BlueSpikeball for finding these textures in the Gamecube version!)

Other than these few, the Gamecube version’s texture quality suffers quite significantly. The PC version’s textures are even worse. Depending on the source texture the difference may be barely noticeable, but in many cases it looks like a bad JPEG recompression. It’s especially noticeable with low-resolution textures and gradients. Here are some examples:

Apart from lower texture quality, the PC version suffers from lack of mipmaps. Mipmaps are smaller copies of a texture used to display it from a distance. Here is a typical texture with mipmaps from the Dreamcast version:

Mipmaps are beneficial because they give the textures a smoother look. The 2004* PC version doesn’t have mipmaps, which makes the game look significantly worse because the distant textures are reduced to pixelated garbage. It’s especially noticeable in motion with a lot of flickering. Thankfully the Mod Loader has a built-in feature that generates mipmaps for all textures, and before the Mod Loader there were texture edits for the PC version that added mipmaps. These fixes are essential if you’re playing the 2004 PC version with original textures.
*The Steam/nextgen console port doesn’t have built-in mipmaps either, instead it generates them on the fly like the Mod Loader. The textures themselves are the same between these ports and the 2004 PC port. While those ports don’t have the flickering, all other points regarding texture quality mentioned in this post apply to the Steam/nextgen console versions as well.

Here are some comparisons with mipmaps on/off in the 2004 PC version:

Anisotropic Filtering off:

Mipmaps off
Mipmaps on

Anisotropic filtering 16x:

Mipmaps off
Mipmaps on

Although anisotropic filtering improves the look of distant textures, it can’t completely remove distant flickering that you sometimes see in motion. The only real solution for that is to use mipmapped textures. But even when not in motion, the mipmapped textures look a little smoother. For comparison, here is what the “maxed out” texture quality looks like.
Anisotropic filtering 16x, Dreamcast textures (SADX Mod Loader + DC Conversion):

Another issue with the PC/Steam/nextgen console ports is texture mirroring. Although the game engine supports mirroring natively, for some reason the developers decided to mirror some of the textures manually and adjust the model UVs to accommodate the change. This wouldn’t have caused problems on its own, but the mirrored texture is often squeezed into the same resolution as the original unmirrored texture, which means the resolution of the final texture that is applied to the model is reduced. In addition, the mirroring in the PC version is usually done by flipping the texture horizontally or vertically, while it would’ve looked a lot better if the texture was rotated. Here’s an example illustrating both problems:

Here’s another example of mirrored textures from Twinkle Park. Although the light texture’s horizontal resolution was increased (or the texture was just stretched), the trap door texture is quarter the size (half the resolution) of the original Dreamcast texture:

In addition, the developers sometimes adjusted the UVs on the models to use a mirrored texture, but forgot to mirror the texture, and vice versa. There are several noticeable problems with texture mirroring in different levels in the PC version. You can read more on that in posts dedicated to each level. Twinkle Park and Lost World are good examples.

It may be hard to discuss artistic changes in SADX because everyone’s aesthetic vision is different. Someone may prefer the more “realistic” look of the new textures introduced in SADX. Those who prefer the original Dreamcast look may think those new textures look lifeless and boring (in some cases they are literally the same textures but desaturated), but to each their own. However, when it comes to textures for levels that weren’t redesigned, the Dreamcast version has the highest quality textures, and each subsequent port has more and more problems coming from mindless recompression.

This is a pretty terrible situation because the Dreamcast version is now the least accessible release, while the inferior PC and nextgen console ports, which are the most accessible ways to play the game right now, have got the worst quality textures out of all versions of the game. Combined with broken lighting and a plethora of other problems in the ports, people who play them first without knowing what the Dreamcast version was like may get a wrong impression of the game. This could be part of the reason Sonic Adventure is no longer remembered as fondly as it used to be. The Steam and nextgen console ports in particular have done a lot of damage to the reputation of the Dreamcast classic.

Thanks to the efforts of the SADX modding community, the textures in the 2004 PC version are no longer an issue. The developers of SADX Mod Loader have added a texture pack feature, which allows to load custom textures in lossless formats like PNG for any part of the game. The Dreamcast Conversion mod restores original PVR textures for the whole game, and the HD GUI mod adds custom high resolution textures for HUD, menus and other 2D items. To install these mods, head over to the “Fixing the PC version of SADX” section of this blog.

Character model downgrades

Character models in SADX are the cornerstone of the SA1 vs SADX debate. They’re one of the few aspects of SADX that can be considered an improvement over the original game as they have more polygons resulting in a more detailed look. It’s particularly noticeable if you look at characters’ hands. Dreamcast character models have “mittens” like many other games at the time, while SADX models feature hands with clearly separate fingers.

From a purely technical standpoint there’s no argument about it: more polygons = more detail = better. But the SADX models aren’t just improved SA1 models with a better polygon count. They are also different in proportions, they use different textures and are missing several effects from the original. But first, let’s have a look at the following comparison just to see how they differ on a basic level. This comparison was done using Dreamcast and PC versions with several hacks, where we set up a test environment to ensure the models are placed in the exact same spot and have the same lighting:

Sonic

Tails

Knuckles

Amy

Big

E-102 Gamma*

Super Sonic


*Apart from some material flags, E-102 Gamma’s model is identical to its Dreamcast counterpart, but there’s a transparency issue with his chest, which will be discussed separately.

Some people prefer the higher poly SADX models, while others say they prefer the original models aesthetically. Some people argue that the SA1 models for Sonic, Tails and Knuckles have proportions resembling those characters in the classic Sonic games, while the SADX models look closer to more recent Sonic games, especially Sonic Adventure 2. This makes sense because SADX came out on the Gamecube after SA2B, and perhaps this prompted the developers to redesign the models so that the newer release wouldn’t look so different from the sequel that came out first on the Gamecube.

I’d also like to mention the redesign of Sky Chase models, which replaced the low-poly “Saturn” style models with more detailed models. This is also an improvement over the original game.

Higher polygon counts and separate fingers are objective improvements, and the rest is a matter of personal preference. However, in many aspects the updated character models are poorly implemented in SADX. Here’s a list of problems with the SADX models that didn’t exist or were less noticeable with the Dreamcast models:

  1. The “fur” textures for all characters were replaced with simple colors or gradients. Some people may not like the “grainy” textures on the Dreamcast models, but replacing the “grain” with a solid color seems like loss of detail. It would’ve probably looked better if the original texture was remade in higher resolution.
    Here’s a comparison of the “grain” texture between versions:
  2. The updates are inconsistent as only the main characters were updated:
    a) Tikal and Eggman only received the higher-poly hands, and not all their models were updated – e.g. Eggman’s low-poly models in Egg Hornet and Egg Viper were not updated at all.
    b) Amy’s model in the cutscene where she is captured by Zero is still using her Dreamcast model with mitten hands. Same problem with Tails in the cutscene where Sonic sees him crash. Gamma’s flashback with Amy also wasn’t updated. Sonic’s Light Speed Dash aura also wasn’t updated.
    c) The jumping/rolling models for characters were not updated. They use the SA1 hand models with SADX hand textures, which doesn’t look too great together with broken vertex welding and lower quality textures. To be fair, vertex welding is broken on the Dreamcast too, but at least it has the correct textures. Lack of updates to anything besides the most visible things is jarring and illustrates the lack of effort put into the model upgrades.

  3. The screenshots seen in the endgame credits were updated to feature new models and environments, but character tutorials and final credit screens still feature the old levels and old models with mitten hands.
  4. The updated models are inconsistent with other models in the game. The higher-poly models of Sonic and other characters look strange when they are standing next to NPCs because the NPCs use much more basic models. This was already noticeable in the Dreamcast version, but SADX made the contrast even more jarring. The best example of this inconsistency is Knuckles standing next to an NPC in the Echidna City. His original model looks a lot more consistent with the echidnas than his SA2-inspired model used in the ports.
  5. The updated models don’t follow the design guidelines from the Sonic Adventure Stylebook (scroll down a bit or search for “stylebook”). They use wrong shapes and proportions, whereas the original models follow them quite closely. Considering that SADX is supposed to be a better version of Sonic Adventure, the updated characters don’t represent the original game’s artistic vision.
  6. The Dreamcast models had some gloss on them, but the SADX models have much more gloss, which makes them look like plastic. Many people find the excessive gloss unappealing, especially in the PC version, where you can install a NoGloss mod to fix it, or use the Lantern Engine mod to tone it down. The gloss difference is the side effect of the inferior lighting system in SADX. Check out the section on character gloss in the Lighting post to find out more.
  7. The new hands are good to have, but Amy has got monster hands with very long fingers and it looks a bit freaky.
  8. The updated Sonic model has an animation error causing Sonic’s eyes to disappear during his “hanging” animation.
  9. The more rounded shoes are good, but the textures used on them were squeezed into one texture, and that texture isn’t very detailed. For example, Amy’s shoes look “dirty” because of the noise that comes from upscaling a low-resolution shoe texture.
  10. There is a visible seam between the upper and lower halves of Big’s body in SADX. Big’s model in particular is a great illustration of how a higher poly count improves almost nothing. Did you know that the SADX model has a higher poly count for Big’s body? I didn’t because it looks exactly the same to me.
  11. Super Sonic has lost the reflection effect (environment mapping) on his body and is now using a simple yellow texture.
  12. Super Sonic’s foot sticks out of his aura (lol).

Some people say the SADX models have better textures. Other than the “grain” mentioned in point 1 above (which is still debatable), this isn’t entirely true. Here’s a comparison of SA1 textures with SADX textures for Sonic:

Dreamcast
Gamecube

You can see that the textures used for Sonic’s face and body (stx_hoho and stx_hara), Crystal Ring (stx_itemring) and the shoe buckle (stx_kanagu) are higher resolution in SADX*, but the textures for Sonic’s jump ball, eyes, nose, teeth etc. are the same resolution. You can also notice that the SADX model uses less textures. This is because most of the shoe textures have been squeezed into one. Normally this wouldn’t cause any issues, but in some cases the combined texture in SADX is less detailed than the individual textures used in the Dreamcast version (see the Amy’s shoe example above).
*Interestingly the “Autodemo” prototype of the Dreamcast version has higher quality character textures that are mostly on par with SADX resolution wise.

I’d like to go back to the “grain” issue again here. The texture in question is stx_btest1, which looks like this:


As you can see, the SADX texture is split into four pieces, which are applied to different parts of Sonic’s body. If we color code the parts, it looks like this. This is obviously an improvement over just one texture in the Dreamcast version, but it also means the resulting texture that gets applied to Sonic’s body is half the resolution of the Dreamcast texture in addition to the loss of “grain” discussed earlier.

The textures that weren’t redesigned in SADX suffer from quality degradation. A common misconception is that the texture quality downgrade happened only in the PC version, but the Gamecube version’s loss of texture quality is also quite significant. For example, look at what happened to the texture you see on Sonic’s jumpball:


Note that all textures in the game have suffered from quality reduction, not just the character textures. More on it in the Textures section.

Even Gamma’s model, which wasn’t redesigned, is suffering from some problems in SADX. There’s a part of his body that looks like this:

This is what it looks like in different versions of the game:

Dreamcast
Gamecube
PC

As you can see, the only version of the game where it renders correctly is the Dreamcast version. The front shield texture is supposed to be semi-transparent so that you can see the light behind it. The texture is still transparent on the Gamecube, but the light part is invisible and you see other parts of Gamma’s body through it. In the PC version the front texture is simply opaque. The same problem affects other robot characters, which also have body parts like that.

Some time ago we found out what was causing this. Gamma’s chest uses a mesh type that is not supported in SADX. However, that mesh type is exactly the same as another mesh type (trimesh), which is supported in SADX, so making it work would’ve been extremely trivial, and even if they didn’t want to support it they could just change a few bytes in Gamma’s model to make his chest use the trimesh type. In the PC version and later ports transparency is disabled entirely by using a constant material with no transparency on the whole model. This also would’ve been trivial to fix, although it may have been intentional.

Also Gamma’s eyes, parts of his feet and head base are supposed to be lit up at all times. The “ignore lighting” material flags for those body parts were removed in SADX for some reason, so Gamma’s eyes are no longer lit up. Same with Big’s eyes that no longer glow in the dark.

Now let’s talk about missing effects. When Sonic rolls around, the blue trail he leaves behind has an interesting “rainbow” effect in the Dreamcast version. The trail is always purple in SADX, and the “rainbow” effect is missing:

Dreamcast
Gamecube
PC

This happens because SADX never sets the correct texture for the effect. It’s supposed to cycle between the first and second texture in SON_EFF.PVM, but SADX sets one of the textures meant for the longer dash trail, which is always purple.

Sonic’s Light Speed Dash aura is also different. It looks more jagged in SADX and its glow is a lot brighter. It’s quite likely that the developers couldn’t get additive blending to work properly with the glow model (which uses many transparent layers), so they decreased the transparency to make the problem less noticeable. However, that resulted in more “jagginess” and a worse look of the aura overall:

Dreamcast
Gamecube
PC

The original Japanese release of Sonic Adventure had an interesting “motion blur” effect when Sonic was running at high speed. It involved real-time replacement of Sonic’s shoes with stretched models to produce an effect akin to what you see in classic Sonic games. In addition to the stretchy feet, the game rendered Sonic’s model multiple times with various levels of transparency to imitate motion blur. In later releases on the Dreamcast the effect was toned down – the transparency was removed, but you could still see the stretchy feet sometimes. In SADX the effect was removed entirely:

Dreamcast JP
Dreamcast US
SADX

Sonic’s model looks glitchy in the SADX screenshot – the shoe buckle is missing and the bottom of the shoes use a strange looking yellow texture. Those are the leftovers of the stretchy shoe effect. In SADX, the code for the stretchy shoes is still active, and when Sonic is running fast the shoes switch to an old model that wasn’t updated to use the final SADX textures. This is why the bottom of the shoes is using the buckle texture, and the buckle itself is missing. This bug has always been visible in official promotional materials, such as the Steam page.

A somewhat similar effect was removed on Tails’ tails. If you go back to the model comparisons near the top of this page, you can see that Tails had more than two tails in the Dreamcast version. Those semi-transparent tails showed up when he was running or flying, creating another variation of the “motion blur” effect. He still retains those extra tails in SADX, but the transparency on them is deactivated, which looks a bit strange:

Dreamcast
Gamecube
PC

Knuckles has also had several effect downgrades. The Shovel Claw has lost the environment mapping effect that gave it a shiny metallic surface:

Dreamcast
Gamecube
PC

Knuckles’ Maximum Heat attack aura is also different in SADX. It looks noticeably worse in the PC version, although the Gamecube version also looks somewhat broken:

Dreamcast
Gamecube
PC

Even with all the problems mentioned above there’s a lot of subjectivity when it comes to saying which models are better. However, in a supposedly enhanced port we shouldn’t have to choose between higher polygon counts for some character models on one side and worse texture quality, removed effects and broken character lighting on the other side. Most of the downgrades discussed here have been fixed in my Dreamcast Conversion mod, where I restored or recreated the missing effects. SonicFreak94‘s Lantern Engine mod takes care of level and character lighting, and ItsEasyActually‘s Dreamcast Characters mod is for those who prefer the original Dreamcast models in the PC version. Learn more about the mods here!

Egg Carrier downgrades

In comparison to Station Square or the Mystic Ruins, the Egg Carrier has received a less radical redesign in SADX. However, the changes introduced in this level range from minor improvements to serious loss of detail and vibrancy. Let’s have a look at what’s been lost in the transition.

An overview of the main area reveals better object draw distance in SADX, loss of the purple tint on level pieces and some minor texture differences:

Dreamcast
Gamecube
PC

The “different” texture used for the green glass floor in SADX is the same texture used for windows in SADX and the Dreamcast version. The unique green glass and reflection textures are not used in this area anymore, and some variations have been removed entirely, so texture variety in this area is reduced in SADX.

Since we’re looking at this overview, let’s talk about the sea textures used in this area when the Egg Carrier sinks. The ocean mesh has a semi-transparent cloud underneath, creating a shadow effect in the Dreamcast version. The ocean in Gamecube and PC versions is more transparent due to additive blending, and the water wave texture is no longer animated, which makes the sea look static and awkward. The strange looking “acid blue” color doesn’t help either:

Dreamcast
Gamecube
PC

The projector beams have some issues in SADX, but the issues are different in each port. The Gamecube version has a semi-transparent outline around each beam, while the PC version’s beams blink randomly. The blinking might be intentional as it is handled in code, but it almost looks like a bug:

Dreamcast
Gamecube
PC

Here’s an enhancement for a change. Some level pieces and objects are textured better in the ports, such as this turbine. This is one of the few things in the game that can be called an improvement without a long list of “buts” accompanying the change:

Dreamcast
Gamecube
PC

This is undeniably an improvement, but it doesn’t compensate for the downgrades this level has suffered. Some of such downgrades are caused by oversights on the developers’ part. For example, there is a glowing animated monorail logo that you’re supposed to see at the monorail station. In SADX it doesn’t display because the texture’s alpha channel makes the animation invisible. To be fair, the alpha channel is the same as in the Dreamcast texture, but the Dreamcast version has no problem displaying the animation:

Dreamcast
Gamecube
PC

The Sky Deck entrance has glowing lines (the monorail) running under green glass. In the PC version, unnecessary processing of material colors gives the glass an incorrect color. In addition, the lines disappear at some camera angles on Gamecube and PC, which doesn’t happen in the original game.

Dreamcast
Gamecube
PC

In Captain’s room, the ship captain’s seat is missing some pieces and animations. Also note the loss of transparency in the background mechanisms with green glass, and missing lighting in the ports. If you look closely you can also see that the skybox looks different in the ports. Its scale was altered because the original scale didn’t work well with the reduced draw distance in this area:

Dreamcast
Gamecube
PC

The cutscene showing the Egg Carrier transforming has dark fog in the Dreamcast version that enhances the atmosphere. The fog is disabled in the ports. Lighting on the Egg Carrier is also missing. If you look closer you can also notice how Eggman’s logo is chopped in half in the PC version because the developers edited the UVs on the model but forgot to mirror the texture:

Dreamcast
Gamecube
PC

Some minor enhancements in the pool area include added Eggman logos on the umbrellas, yellow vertex colors and improved collision, but the lighting and textures were made so bright it almost looks like a hospital.

Dreamcast
Gamecube
PC

Eggman’s private quarters also suffer from bad lighting in SADX. Note how the shading on objects becomes less detailed with each port:

Dreamcast
Gamecube
PC

The Dreamcast’s palettized lighting allows to create interesting multi-color effects, and this level uses a lot of color transitions. An example of such lighting is the glass table in this room, which lost its lighting in the Gamecube version and was made bluish green in the PC version because of unnecessary material colors:

Dreamcast
Gamecube
PC

The bridge area loses the green tint on everything and has brighter and simpler lighting. The Dreamcast version appears to have richer lighting than the Gamecube version, while the PC version is the worst of all three:

Dreamcast
Gamecube
PC

Object lighting has also suffered in SADX. For example, the doors have lost the green tint, which SADX tried to compensate with vertex colors, which in turn broke in the PC version. Also note how the lighting on Sonic is more generic in the ports:

Dreamcast
Gamecube
PC

In the original game, reflective green barriers show up on some doors during Gamma’s story to indicate that you can’t go inside. While the code for the barriers is still there in SADX, the function call to render the barrier’s model was disabled. As a result, these barriers are never seen in SADX.

Dreamcast
Gamecube
PC

The prison area remained mostly the same, although fog was reduced and some subtle lighting effects are missing on the ceiling fans. If you look closely you can also see that the secret Chao egg in one of the cells has lost its texture and is now solid black:

Dreamcast
Gamecube
PC

The buttons that you need to press to unlock the Egg Carrier Chao garden are broken in the ports. They are supposed to have a shiny reflective surface that consists of two layers, but they can’t render properly in SADX and show the tiles below instead:

Dreamcast
Gamecube
PC

Gamma’s upgrade rooms have lost their rich ambience because the unique palettes for level and character lighting are no longer there:

Dreamcast
Gamecube
PC

The Chao transporter effect is less vibrant and suffers from transparency issues in SADX:

Dreamcast
Gamecube
PC

The Egg Carrier has only marginal changes in SADX (such as better texturing of some level pieces and objects) that could be counted as improvements, but everything else is a major letdown. Looking at the two versions side by side is disappointing because it demonstrates the incredible amount of wasted potential for improvements in the supposedly “enhanced” port. To play the original version of this level, you can use the Dreamcast Conversion mod together with the Lantern Engine mod that reimplements Dreamcast lighting. More about mods here.

Mystic Ruins (Past) downgrades

Mystic Ruins Past is a relatively small location, but even a small level like this suffers from downgrades ranging from minor problems to complete removal of things that define the level’s theme.

From a quick look it doesn’t seem too bad. Other than a strange looking skybox in the PC version, there are no immediately visible downgrades in the Echidna City. SADX fixes lighting on the trees that ignore it in the Dreamcast version and adds vertex colors around some areas, which can be counted as an improvement:

Dreamcast
Gamecube
PC

Not a downgrade, but the well is now shut to prevent you from seeing the Dreamcast water texture. The texture on the columns was flipped for some reason – a rather nonsensical change because the texture itself wasn’t changed:

Dreamcast
Gamecube
PC

The Emerald Altar area has more noticeable differences. SADX adds prominent fog and the lighting is brighter and more washed out:

Dreamcast
Gamecube
PC

The most noticeable difference in this area is the sea textures. Like other Adventure Fields, the Past also uses additive blending for the water, which consists of two texture layers (and another layer for the distortion effect on the Gamecube). From a technical standpoint it can be considered superior to the original opaque water texture, but color selection is a bit strange as it doesn’t fit the stage’s theme very well. Another problem is that the SADX water is too dark and too transparent, which makes the bottom of the skybox visible through it. The sea also ignores lighting and is affected by fog in the PC version, which makes makes it look worse when the Emerald Altar is on fire:

Dreamcast
Gamecube
PC

In the Dreamcast version the water around the altar reflects some objects like palm trees and columns. This effect is created by making the floor transparent and placing “reflected” models underneath it. These reflections are still present in the SADX level, but they fail to render properly due to the game’s transparency problems. In addition, the water texture was made so transparent you can barely tell there is water. The reflections were especially effective at creating the atmosphere in cutscenes featuring the Emerald Altar on fire, which are less impressive in SADX.

Dreamcast
Gamecube
PC

Perhaps the most disappointing SADX downgrade in this level is the fire effect. In the Dreamcast version the lighting transitioned between darker and brighter shades of red by alternating between two palettes – more on that in the Lighting section. This effect is removed in SADX. The transitions also affected some objects, such as trees, which now have simpler lighting. The PC version adds thicker fog that doesn’t help the scene.

Dreamcast
Gamecube
PC

Loss of lighting detail is also visible in the Master Emerald area, where distant scenery is no longer tinted red, the Master Emerald is fullbright and the glow of the emeralds blends with the background:

Dreamcast
PC

Character lighting in this level was also downgraded quite badly. The Gamecube version in particular lacks detail besides basic coloration most of the time. You can still see some slight coloration depending on the camera angle, which suggests that a different light direction might’ve helped.

Dreamcast
Gamecube
PC

In conclusion, the Past has suffered from less downgrades than other areas in SADX, but loss of reflections and the unique two-palette fire effect make it a lot less impressive than the original level. While it doesn’t look too terrible overall, the Emerald Altar area cannot be called an improvement over the Dreamcast version, which is clearly superior. To revert to the original version of the level on PC, use the Dreamcast Conversion mod (which restores reflections), and the Lantern Engine mod that restores the fire blending effect. Read more about mods for the PC version here.

Mystic Ruins downgrades

The Mystic Ruins were redesigned in SADX with new textures, particularly in the main area. While the new textures are not bad for the most part, the level has had several changes that can be considered downgrades. Much like elsewhere in SADX, those downgrades primarily have to do with lighting and transparency.

The differences in lighting are noticeable as soon as you arrive in the stage. Note how the lighting on Sonic is simpler in SADX, and how the PC version looks almost the same during night and day.

Dreamcast
Gamecube
PC

Here’s an overview of the main area, which received the most changes in the ports. Some people may prefer the more “detailed” land textures in SADX. The lighting in the Gamecube version is a lot better than in the PC version, although it still looks a bit too bright at night. In the PC version you can’t easily tell which time of day it is because all screens look almost the same.

Dreamcast
Gamecube
PC

The Egg Hornet area was also redesigned. The palm trees in the Dreamcast version ignore lighting for some reason, which is fixed in SADX. The Gamecube version looks fine, but the PC version has broken lighting. The land in the PC version looks lit up in the evening and at night, and you can only tell the time of day by the sky texture.

Dreamcast
Gamecube
PC

The pond is one of the most criticized areas in the PC version. The Dreamcast version has a static water texture, the Gamecube has a moving distortion effect, and the PC version has a static water texture with additive blending. The waterfall is also more colorful in the original game. Whether DC or GC looks better in this area is a matter of preference, but the PC version (and all subsequent versions based on it) has the worst looking pond:

Dreamcast
Gamecube
PC

The sea textures were changed as well, they don’t look too bad with the Gamecube’s distortion effect, but the animation of the waves washing the rocks doesn’t fit very well because of transparency issues. The problem is accentuated in the PC version, which doesn’t have the distortion effect:

Dreamcast
Gamecube
PC

A similar problem happened to the water wave animation on the rocks here. Note how the PC version’s sea is even less transparent and adds unnecessary fog:

Dreamcast
Gamecube
PC

The rock that blocks the passage to Angel Island stands out in the PC version because of material color problems:

Dreamcast
Gamecube
PC

The Angel Island area was also redesigned. The “redesign” primarily involved removal of many decorations, such as trees:

Dreamcast
Gamecube
PC

This part has also lost some decorations and detail, making the area look more empty and lifeless:

Dreamcast
Gamecube
PC

Minor complaint, but the glow of the Master Emerald is more vibrant and “green” on the Dreamcast:

Dreamcast
Gamecube
PC

The vibrancy of the Ice Cap area was reduced significantly, and the environment mapping effect on the ice was made more transparent and less shiny. The area looks a lot more static and less impressive as a result. The PC version adds blue material colors, which aren’t a problem but they don’t help the vibrancy too much:

Dreamcast
Gamecube
PC

This plant was changed in the ports, and its transparent parts were replaced with copies of non-transparent parts. Since the original model for this plant works fine in SADX as-is, it was unnecessary to replace it. In addition, the rustling grass sound made by this plant no longer loops in SADX.

Dreamcast
Gamecube
PC

The jungle area is also different in SADX. Some of the differences can be considered downgrades. The original game uses fog to enhance the atmosphere: for example, when you descend into the jungle, the fog thickens and you can’t see too far, but if you climb up or go to the temple area, the fog gradually disappears. This effect is removed in SADX. The fog is especially problematic in the PC version, where it washes out distant colors when looking at the jungle from above.

The top part of the jungle uses a lower resolution texture in SADX, but the models are less flat. The PC version completely ruins the jungle with broken lighting, fog and unnecessary material colors. In addition, the SADX jungle entrance was not adjusted in the ports so it now clashes with the SADX redesign of the main area.

Dreamcast
Gamecube
PC

The water texture in the jungle is too transparent in SADX so it looks as if there is no water at all. Interestingly it’s one of the few areas in the Gamecube version where the water doesn’t have the distortion effect, which would’ve helped here. The water being too transparent is particularly a problem in the PC version because it’s the only version where the water is no longer animated:

Dreamcast
Gamecube
PC

The decorations around Big’s house have lost all animations in SADX and are now completely static:

Dreamcast
Gamecube

The Final Egg base model has transparency problems in all ports, which are more prominent in the PC version. The light beams don’t render properly and go behind the glow effect. They also get dark outlines because of layering issues with the skybox.

Dreamcast
Gamecube
PC

Inside the base there are noticeable lighting differences. SADX removes the greenish tint across the whole level, reduces lighting detail on Sonic and replaces a few textures:

Dreamcast
Gamecube
PC

The tubes in this area are more opaque and less reflective in SADX:

Dreamcast
Gamecube
PC

Here’s an overview of the lower segment of this area. Note how the PC version has draw distance artifacts near the top:

Dreamcast
Gamecube
PC

Some people might think the lighting in this area was changed to give it a more “rusty” look. We can confirm this isn’t true because the vertex colors in this stage look almost the same as the Dreamcast version without lighting. Here’s a screenshot of the Dreamcast level with fullbright lighting compared against the SADX redesign of this area with lighting from the PC version:

Dreamcast (no lighting)
PC

As can be seen from above, this is not a matter of design – the textures simply look that way without lighting. Although the SADX version of the level has lighting, it doesn’t affect the level as profoundly as the original version.

The SADX version of Mystic Ruins has less downgrades than Station Square, and the Gamecube version looks fine in some areas, but lack of proper lighting, removal of decorations and strange design decisions regarding color vibrancy make this Adventure Field feel unfinished. It could have been an interesting redesign if it wasn’t for the massive amount of issues plaguing almost every single change introduced in SADX. These issues are fixed in the Dreamcast Conversion mod, which reverts this level to its original design. For those who prefer the SADX look of the Mystic Ruins, the Lantern Engine mod can improve the ambience by adding back Dreamcast lighting without reverting the level to the original version. Check out this section for more information on how to install mods on the PC version.

Station Square downgrades

Adventure Fields had the most drastic changes in SADX. Station Square in particular had a major redesign with many new textures. The redesign itself, however, is somewhat questionable. Although it adds some fake shadows using vertex colors and semi-transparent models, it also loses a lot of detail, and some of the visuals are broken. Let’s compare the level side by side between Dreamcast, Gamecube and PC versions and see which one holds up better.

The area where you fight Chaos 0 was originally a red brick building with a clock tower. In SADX the clock tower was replaced with a smaller copy of the building’s lower segment. If you look closely you can see this area uses less unique textures, which are also lower quality than the original textures. Another problem with this redesign is that it creates an inconsistency with Speed Highway Act 3 because this is supposed to be the same building you enter as Knuckles or leave as Sonic in that stage. The building in Speed Highway still has the old design with the clock tower.

Dreamcast
Gamecube

Some people claim that SADX has “better” asphalt textures because the SADX texture is supposedly “more realistic”. This can be proven wrong by just comparing the textures side by side. Let’s have a closer look: here’s the asphalt texture from the City Hall area from both versions of the game and my quick attempt to downgrade the original texture to the SADX level of quality.

One of the most serious downgrades that happened to Station Square is the window reflections. In the original game there were several reflection textures for different windows during day, evening and night, and the distortions reacted to camera movement. In SADX, most windows use the same reflection texture at all times, and the UVs on the windows were adjusted to make the reflections look less vibrant. The city hall area had the environment mapping effect on windows disabled entirely so the windows look completely static:

Dreamcast
Gamecube
PC

Other parts of Station Square still have the environment mapping effect, but it looks less vibrant than on the Dreamcast because of edited UVs and because most windows use the same texture:

Dreamcast
Gamecube
PC

The loss of palette lighting made the level look different at night. The bluish tint is gone, and the level pieces that were lit up on the Dreamcast (such as windows) no longer change at night. The Gamecube version is darker, and the PC version looks almost the same during day and night:

Dreamcast
Gamecube
PC

Transparency effects in some areas were removed in SADX. For example, the doors and windows in this building originally had two textures to make it look like you could see what’s inside. In SADX one of the layers is no longer visible because the top texture with the environment mapping effect was made opaque. In addition, the texture on the door is screwed up and fills only half the door. This isn’t a design change because you can clearly see the door handles moved to the upper part, which doesn’t make sense:

Dreamcast
Gamecube
PC

A similar downgrade happened to another reflection in the Casino area. It’s harder to see what’s behind the glass:

Dreamcast
Gamecube
PC

The sewers area received a minor redesign. The water texture is no longer animated, its resolution wasn’t increased either, but the color was changed. The distortion effect takes care of water animation on the Gamecube, but the PC version reverts to a Dreamcast-like look which now looks awkward because the water texture isn’t animated. Some vertex colors were added to compensate for the loss of palette lighting. The lighting in the sewers changed depending on the time of day in the Dreamcast version, which didn’t make much sense. In SADX the sewers area looks the same regardless of the time of day.

Dreamcast
Gamecube
PC

Station Square ocean is one of the few areas in the game that use a different blending mode for the water (this mode is used only in Adventure Fields, Emerald Coast and some Chao Gardens). Some people prefer this to the low-resolution Dreamcast water texture. Others may think the SADX version looks lifeless and too “acidic”. The Gamecube version has a distortion effect, but the animated waves on the seashore are gone:

Dreamcast
Gamecube
PC

The “acidic” look of the sea is especially noticeable during the day:

Dreamcast
Gamecube
PC

The color of the sea changed depending on the time of day in the Dreamcast version. In SADX the sea ignores lighting but uses a different texture for evening. It looks a bit strange at night because the sea is lit up in the dark surroundings:

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The sewers in the station area also have a different water texture. There is also some strange shadow that looks like a bug:

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The glass walkway above the Twinkle Park entrance looks less vibrant because the glass was redesigned to use a different model with different UVs and a texture that is used on almost all glass surfaces in SADX. The environment mapping effect on the planet decoration was replaced with a solid texture, making it look like a ball. In addition, parts of the Twinkle Park entrance building no longer light up at night:

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Here’s a closer look at the reflections. Note how the environment mapping effect is less vibrant on the Gamecube:

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The building itself has lost transparency at the base, so the bottom of it is now solid. It’s also no longer illuminated at night:

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Like the sewers, the Dreamcast version of Station Square Twinkle Park area changes lighting depending on the time of day, which doesn’t make much sense because it’s located indoors. This was changed in SADX, and now the Twinkle Park entrance always looks the same:

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Similar to Speed Highway Act 3, the cars in Station Square have lost their shiny metal surface (the cars you see during the Egg Walker fight are still shiny, however). Their windows had a blue sky texture (which didn’t make sense at night) that was replaced with the familiar generic green glass texture. Some people may prefer the more detailed car textures in SADX, which supposedly makes them more “realistic”. However, the loss of the shiny metallic effect makes the car less realisitc. They now look more like plastic toys:

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The police cars have lost transparency in their flashers, which not only looks less “realistic”, but also makes the inner pieces invisible. They were supposed to rotate as the car moved.

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There are other minor downgrades, such as removal of transparency in pool chairs:

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The windows in Tails’ upgrade section are now shut because of transparency problems:

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When playing as Tails, the station doors are misplaced, which looks awkward and makes some Z fighting visible in their upper segment. This doesn’t happen in the Dreamcast version:

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Another minor bug causes Sonic’s shadow to be overlapped by the crosswalk texture:

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Another problem with the redesign involves overlapping level pieces, which create a strange looking gap near the newsstand. This doesn’t happen in the original version of the level. Note how the reflection has also been toned down:

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The newsstand itself has suffered from texture quality degradation and stretched UVs (look at the newspapers):

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The building next to the newsstand was also slightly redesigned, adding new signs:

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The issue with this redesign is that the “Station Square Books” sign has a low resolution texture that stands out when placed next to the sharp-looking posters:

If you look closer, you may notice that the supposed bookshop sells food!

Something similar happened to the “Urban Chillin” store in the clock tower area, where the sign was changed to “ATOZ School”, but the texture for the inside area wasn’t changed, so the “ATOZ School” appears to have clothing on display. To hide this inconsistency the window was made more opaque, but you can still see the clothes through the glass. Also note how the “ATOZ School” sign itself looks somewhat amateurish compared to the original Dreamcast sign, and it is no longer lit up at night:

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The texture for the “Casino Ken” sign that was added in SADX is low resolution and looks particularly jarring next to the polygonal sign for the Casinopolis entrance. It’s also not centered on the actual entrance, the glass door:

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One of the strangest bugs in SADX involves the hotel door, which appears to ignore lighting at all times. This happens because in SADX the lights are supposed to turn on inside the hotel when you go there at night. “Turning on the lights” involved adding an “ignore lighting” material flag to everything in the area. However, the code for turning on the lights is bugged and forces the hotel doors to ignore lighting even when you’re outside the hotel. This makes the doors look strange in the evening and at night:

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Station Square loses a lot of its original atmosphere in SADX, and the fake shadows arguably don’t compensate for it. It’s the most severely downgraded Adventure Field in the game, with loss of texture variety, UV and lighting downgrades, missing effects, transparency issues and various visual bugs. However, this level can be reverted to the original version with the Dreamcast Conversion mod. Check out this section on how to install mods on the PC version.