As can be seen in the Action Stage and Adventure Field sections, almost every area in the game had changes in SADX, and the bosses are no exception. In many cases the problems seen in boss battles are related to stage downgrades, but there are also several boss-specific effects broken or removed, and certain issues are specific to the PC port. This post is an all-in-one boss marathon so it’s going to be a little long, but that’s only because all bosses in the game have issues that weren’t there in the original game.
This is the area you see first when you start the story, and one of the most memorable scenes in the game. Most of the downgrades to this area are the same as Station Square downgrades: for example, window reflections had the environment mapping effect disabled and are now a simple texture. Here’s an overview of the area as seen in the first cutscene:
You can see that the variety of textures is a bit less impressive in SADX, for example the windows on the police car use the same texture as window reflections. In addition, none of the glass surfaces have the distortion effect (environment mapping) that was there in the Dreamcast version. The back lights on the police cars are no longer lit up for some reason.
Also, during the cutscene you can notice that the lights cast on the ground by the police cars are no longer there in SADX:
When Sonic jumps on top of the police car, you can see that the flashers no longer have a reflective surface, and the rotating pieces inside them are missing:
Those rotating pieces are still there, but you never see them because the parts of the police car model are rendered in an incorrect order.
Finally, let’s have a closer look at the police car. The original car’s design was trying to create a cinematic look similar to this, while in the SADX version the reflections were replaced with low-resolution textures. Even the windshield has lost its textures for some reason.
Some engine changes/differences in SADX affect all areas in the game, including bosses. Right before the battle with Chaos begins, you can see that he looks slightly different in each version of the game:
The greenish glow around Chaos’ chest and torso in the Dreamcast version is added by the palette lighting system, which was removed in the ports. But the most noticeable difference is the blue coloring of Chaos in the PC version. It is caused by an oversight in the PC port, which makes the game process material colors even when it is not necessary. The console versions of the game don’t do that (but the nextgen console ports do).
The area itself is also affected by the removal of palette lighting. Along with missing window reflection effects it results in a less vibrant looking environment in comparison to the Dreamcast version:
The lack of palette lighting causes Chaos to lose some detail on his torso:
As you fight this battle, you may notice that the lighting is different, but the most noticeable change is the windows. Now you can barely see the city background through them, and even when you do, it is missing one layer so the “parallax” effect is no longer there. It would still look kind of acceptable, but the added fog washes out the background in both ports:
The columns in this fight are supposed to become transparent when they are close to the camera, but this only happens on the Dreamcast. The code to make them transparent is still in the ports, but the level has these columns duplicated as static models to hide the transparent ones completely. This was most likely done to hide transparency issues with Chaos’ body overlapping those columns.
The pond has lost the murky green texture and is now more transparent. The reflection effect was also toned down slightly:
Chaos has lost the green specular lighting specific to this area and looks more “generic” now, although the Gamecube’s distortion effect compensates for it somewhat. SADX also adds a visible bottom texture, which was black in the original game:
When fighting Chaos, you can also notice the green glow on rings and characters as they also use a green specular palette in the original game. It’s missing in SADX:
In the Dreamcast version the pond has a green texture while Chaos is swimming in it, but changes to a different texture when you beat him. You can see it briefly before Chaos falls into the pond and after you defeat him. This was removed in SADX.
This boss has suffered mostly from lighting downgrades. In the Dreamcast version Chaos’ model used a special palette that gave it a dark, intimidating look. The Gamecube version’s attempt to recreate that is only somewhat successful, and the PC version looks the worst as always:
During the fight you may notice that the green glow on the Eggmobile and some objects is now given to Sonic instead, and something is wrong with the skybox in the ports:
The skybox is split into two pieces, and one of them is animated. This is the same as in the Dreamcast version, however in the ports the animated piece has an incorrect Y position. It’s supposed to be below the ship so that you can see it only near the edge of the battle area. However, in SADX it is placed right into the sky, creating visible seams between the animated and non-animated layers of clouds:
This boss fight has a lot of downgrades stemming from code bugs in the game’s transparency sorting system, as well as some lighting downgrades. Let’s discuss lighting first, since it’s the first noticeable difference you see right away.
Like Chaos 6, Perfect Chaos also uses a special palette in the Dreamcast version. The ports don’t compensate for it in this case, and Chaos’ model just has no lighting as a result:
The Egg Carrier 2 model has excessive white specular lighting in SADX that makes it look strange. It looks particularly bad when the camera zooms in onto the Egg Carrier model. Lower texture quality is also quite noticeable if you look at the background.
Now let’s discuss broken or missing effects. Here is a video comparison of the scene when Chaos gets attacked by Super Sonic:
There are several problems with the scene compared above:
- When Perfect Chaos is hurt, he explodes into water splashes that fly all over the place. The animation for these splashes is stuck on the last several frames in the Gamecube and PC ports, which makes the whole scene less impressive.
- The waterfalls have a particle effect at the bottom, which is missing in the ports. Well, it’s not missing, but it shows up only a few times depending on the camera angle. This is caused by an issue with the alpha rejection system, which makes them invisible.
- There is some faint mist around Chaos’ location, which also randomly appears and disappears in the ports due to a bug with alpha rejection. More on why that happens in the Transparency section. Most of the time you just can’t see it.
- When Chaos emerges from the water, the tornadoes around his body fade in slowly in the Dreamcast and Gamecube versions. In the PC version they just pop in.
- On the Dreamcast the tornadoes around Chaos’ body have animated UVs that make it look like the tornadoes are spinning in opposite directions. The animation is still there in SADX, but it’s harder to see which direction the tornadoes are spinning because the animation is choppy. This is caused by two things: 1) the animations have been simplified in the ports 2) the animations themselves are faster because of the increased framerate in the ports.
Let me also briefly mention the Super Sonic model. His body has lost the environment mapping effect and is now using a static yellow texture. The distortions created by the environment mapping effect react to camera changes, but the yellow texture always looks the same.
Apart from losing palettized lighting like the Mystic Ruins, the Egg Hornet battle has some other changes. For example, the metallic “reflections” on the Egg Hornet model are less vibrant in the ports because SADX has the environment mapping effect toned down:
When the Egg Hornet attacks Sonic, it rotates as if it’s digging the ground. This works fine in the original game and the Gamecube port, but the rotations are missing in the PC port:
This boss fight was updated to reflect the changes made to Station Square, but the cars in this area are still using their shiny Dreamcast models as opposed to the updated SADX models you can see in the Adventure Field. However, the most noticeable problems with this boss are 1) lighting on the Egg Walker model and the rest of the stage, and 2) missing skybox (obscured by fog) in the PC version.
If you look closely, you can notice that the sky is slightly more purple in the Gamecube version, which is the same color as the missing skybox in the PC version. This is caused by added fog. The Gamecube version has several fog modes that allow the fog to disperse in different ways, while the PC version only has linear fog, which is why the sky is obscured completely by it.
This area is suffering from major lighting downgrades and loss of detail, which are noticeable even in the cutscene leading to the boss fight, although the beginning of it doesn’t look too bad on the Gamecube. As always, the PC version is the worst of all:
This low-resolution wall texture behind Sonic wasn’t updated. This goes back to an argument made earlier that the game was only updated in areas that had rendering issues in their original designs, and the “upgrades” came out of necessity rather than a legitimate attempt to improve the experience. The lighting on Sonic isn’t too bad here though:
The area where you see the Egg Viper for the first time suffers from lighting downgrades, with the green shading missing entirely and the Egg Viper model being lit up for no reason on the Gamecube. In the PC version lighting is almost completely missing in this area.
The walls in the area where you fight the Egg Viper were changed to look more “rusty”, and the spinning dot effect behind the walls is no longer visible. The lighting was also simplified, although the Gamecube version doesn’t look too bad. The lighting on the platforms is also simpler in the ports.
The Egg Viper fight had a few unique lighting effects that barely survived the Gamecube transition and are completely missing in the PC port. But first, let’s look at the start of the fight to see the spinning dots effect in motion. You may also notice that the Egg Viper model has lost its specular glow in the ports:
One of Egg Viper’s attacks is a big explosion. This explosion also colors the walls red in the Dreamcast version. The effect is still there on the Gamecube, but it isn’t as bright. In the PC port the effect is completely missing.
A similar effect can be seen when Sonic hits the Egg Viper. This time it’s a bright red flash, which is also less bright on the Gamecube and missing completely on PC:
Another effect is seen when the Egg Viper charges a ball of plasma to attack Sonic. On the Dreamcast the walls flash blue with an increasing amplitude. This effect is broken in all ports. On the Gamecube the walls lose all lighting, and in the PC version nothing happens:
The boss area was redesigned to reflect the changes to the Adventure Field. Other than minor differences in character lighting it doesn’t look too bad, perhaps even better than the original stage. It also adds lighting to the door, which is fullbright in the original game.
Apart from issues specific to the Adventure Field where this fight takes place, there are some problems with the E-101R boss. The model loses the subtle pink specular light for generic white gloss in the ports, but the main problem with it is the issue with the glass floor, which is specific to the PC version. You can see that the particle effect has transparency sorting problems with the glass floor on PC:
When Beta does the ramming attack, the effect around his body is less vibrant in the ports. For some reason it’s blue on the Gamecube and dark grey in the PC port. If you look closely, you can see that the Dreamcast version of the effect is properly textured, while the SADX version is not:
Some texture quality downgrades happened with the textures used for ZERO and E101R boss fights as well. It is particularly visible on explosion and “rainbow shield” textures. Here is a brief comparison:
As you can see, all bosses have downgrades in SADX, and the boss fights that were the most impressive on the Dreamcast (Chaos 0, Egg Viper, Perfect Chaos) have suffered the most. The Dreamcast Conversion mod resolves all issues discussed here. Visit this page to learn more about SADX mods.