The Supreme Topic of 'Other' Knowledge.

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OK, Mr. Wiki Man.

 

No unused chucks in Special Stage 8?

 

Nope. It's just a static image.

 

I'm confused. Are they supposed to wrap around in a single layer? Are they multiple layers of one BG? I'm just not quite sure what I'm looking at.

 

The backgrounds in Sonic CD are 512px wide and wrap around as you rotate around the stage (except for the secret 8th one, which is just a static image of Eggman's face). They use up both planes to give it perspective. These are chunks for said backgrounds that went unused that appear to possibly could have made the backgrounds 1024px wide instead on certain layers, but there just isn't enough VRAM to allow that, considering a lot of it is already taken up by the double buffered rendered stage graphics. Also, by "unused tiles", for instance, you never see those green planets in special stage 1.

As for the potential proper background layout, here's stage 1 again for reference. Here's what's used in-game:


And if the arrangement of the data has anything to say, then it may have intended to look like this:

 

Ahhh, now I get it. Thanks!

 

It would be nice to see these modded into the TaxStealth Sonic CD ports.

 

So, now I am *very* certain that these are background extensions, because I just noticed this in stage 4's background, when it wraps around:


There's a seam! But if I add the unused chunks...


Seamless. Even when it wraps around.

Hell, with some refactoring, these could work in the original MCD version. Would involve changing the rendering to draw new columns as you scroll, but it's doable. The original code just slaps the chunks onto the planes on load time and calls it a day.

 

Just checked on Origins and sure enough, that transparent cloud cuts and loops right at that same spot. Very cool find!

Just playing devil's advocate to eliminate this idea in my head: if the full size had been used, perhaps these extended layers didn't work well with the more trippy background visuals behind them, like just improperly or just causing motion sickness or something? I know it's unlikely; just something I wondered and wanted to rule out.

 

Nah, there's just not enough VRAM to support them with the system they have (which is to load the background into VRAM on load time and leave it). 1024x256px planes require 0x2000 bytes to be allocated in VRAM for each plane (the 512x256px planes just need 0x1000), and the majority of VRAM is already used up.

Tricks could have still been used to get around the limitation, but this is Sonic CD we are talking... Maybe they split the background into chunks so they could load in new ones as it scrolled. Unfortunately, there's not really any code that I've seen that backs this up.

 

I was going to suggest that a longer background would have to rotate more quickly, but then I had a look in-game... and there are two "Earths" in Special Stage 1, which might suggest they were planning for bigger backgrounds but had to compromise.

I take it there are no clues in the prototypes?

 

I've yet to look at the prototypes in depth, but I'll get to it eventually.

 

Double posting, but I feel like it's warranted. The 510 prototype, for what stages it does have, does have extended background chunks that go unreferenced. No code for loading in new chunks are the background scrolled exists (honestly, that would have been very tricky to pull off with only 2 sides to load chunks into, considering that most of the time, both chunks are visible on screen, on top of the parallax).

However, I did make rips of the prototype stage 3 background:




Its unused chunks:

And potential extended background with those unused chunks:

 

T-t-t-t-triple post! Because, I just noticed something small but kinda funny to me, while on the topic of backgrounds in the special stages. In the original, in stage 7, the background has these small builds in the front:


But in the 2011 Taxman remake, they're not present:


***LITERALLY UNPLAYABLE***

 

wtf i hate taxman now shitty ass port hope he goes bankrupt

 

To be serious, honestly, I'm considering the 2011 remake less and less of a port. There's a number of things that are very obviously guesswork (peelout/spindash, Collision Chaos pinball flipper physics, and the water countdown speedup in the special stages come to mind). I did already write up on the special stage water countdown speedup thing, I should do more when I get the chance.

For what it's worth, though, in that case, he still did a damn good job.

 

Shmuplations has posted a new Takashi Iizuka interview, focusing on Sonic Team USA + Heroes' game design

 

So, remember these unused sprites?


Found some unused animation data that makes use of them!


The animation after this is just the last sprite (the one where his feet are sunk in a little) on a loop:


Falls right in line with this concept art:


Might have something to do with this unused and unfinished mode for Sonic's object:

 

Will there be a more technical writeup on this in the future?