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Author Topic: Altered Beast compression - replacing graphics (concept pics inside)?  (Read 2184 times)

fusaru

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Altered Beast is a very well known game, yet I was unable to find information about the compression used. I've tried every decompressor I could find, but they won't detect anything inside the ROM. Is the compression method for this game known?

I do have a bit experience with exchanging graphics (e.g. replaced the "Scientist" with "Preacher" in Soldiers of Fortune), and I though spicing up Altered Beast would be a nice project. The game already has two very competent hacks, one for color and one for voice files.
http://www.romhacking.net/hacks/2707/
http://www.romhacking.net/hacks/2637/

The game could also use a bit of graphics editing.
Some graphics contains obvious flaws that can't be fixed by color editing, e.g. black stripe in Zeus' body, black horns on first boss, wrongly indexed colors in stage 5 background. Generally speaking the graphics feel a bit rushed, like they have been resized with a program and hardly cleaned up by hand.

Here's what I came up with in a few minutes of drawing around in GIMP with a sprite sheet (ripped by radspyro).
All these consider original sprite sizes (so they could be replaced 1:1), only using colors from each sprite's or background's respective color palette, 8x8 pixel background tile size etc.
 

For this  mockup I did: a bit more hero character detail, hair color fix (just painted over with flesh tone), life bar like in the arcade version, less shadow on foreground objects for a better feeling of depth, shadow on score and life counter, smoother background gradients by better dithering patterns in a 8x8 pixel space. Then just some palette editing (colors are from a private hack btw. pyron's colors are better so no need to released it)
The magic orb on the right was made about 95% fully automatic by GIMP, same colors as original image. The only thing I had to to by hand was the grid for the bricks in the background. Background use more work, but facial details look better


And here some enemy "studies" so to speak.
left original, middle reworked with original palette and more details, right reworked with new palette (possible ingame without breaking anything, colors are from my private hack), needs a bit more optimization but then again, this is like a 15min job.

Nothing groundbreaking, but maybe the game can be made a bit better this way. So, is anbody aware how this game stores it's graphics? I'd like to do more sprites but it's obviously in vain if they can't be put into the game and tested if everything really works.

EDIT: screens reuploaded
« Last Edit: March 13, 2016, 03:30:21 pm by fusaru »
(MD hacks):
Complete --> see contributions page
Twin Hawk (arcade graphics), Toki

Grimlock

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Re: Altered Beast compression - replacing graphics (concept pics inside)?
« Reply #1 on: March 10, 2016, 07:53:16 pm »
Altered Beast is a real classic.  It looks like you're making some good progress with what you've been able to do so far.  I don't have any answers regarding the compression, I just wanted to chime in and say it looks like a worthy project.  :thumbsup:

BTW, the top image doesn't appear to be loading...

tryphon

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Re: Altered Beast compression - replacing graphics (concept pics inside)?
« Reply #2 on: March 11, 2016, 03:50:25 pm »
I can't see your pics, but I can have a look at the game code if you want. Which version do you work on ?

fusaru

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Re: Altered Beast compression - replacing graphics (concept pics inside)?
« Reply #3 on: March 12, 2016, 05:10:18 am »
Thank you both for the encouraging words and offer. I've reuploaded the concept pics. Time for a new file host I guess...

I thought I'd be best doing this for the same version the previously mentioned hacks are also based on:
Altered Beast (UE) (REV02) [!]

I've got no experience with compression sadly. This is just a hobby for me, with no professional background, and all I've done so far is working with graphic editors, palette editors and tracing a few values with a hex editor and debugger emulators.

In case someone could find a way to decompress the artwork it'd be great. I'm currently collecting more experience by reworking Tatsujin/Truxton,a game that has a huge amount of uncompressed artwork.
(MD hacks):
Complete --> see contributions page
Twin Hawk (arcade graphics), Toki