Turok 3 Incorrect Shadows

[AmbientMalice]

I believe Turok 3 uses auxiliary framebuffer for shadows, whereas Turok 2 used stencil shadows. The shadows render better than Glide64, but they're too dark.

GLideN64:

Angrylion:

[gonetz]

Savestate please.

[AmbientMalice]

https://www.sendspace.com/file/17np8s

[gonetz]

I guess I found how it works: manipulation with texture format again. Auxiliary buffer has format 8bit intensity, but when game uses it as texture, texture loaded as 8bit intensity-alpha. Alpha makes the shadow translucent. I simulated this in shaders, but the shadow has strange boarder.

[Predator82Germany]

& too dark

[gonetz]

Wrong intensity is a minor defect.

[AmbientMalice]

Does anti-aliasing have any effect on the softer shadows?

[gonetz]

No. I think, the shadow intentionally made "hairy". It looks like this with software lle too. Dark bound problem is probably solved by proper pixel coverage emulation, which is not implemented in GLideN64. I can't explain though, why shadow itself is darker than with soft lle.

[AmbientMalice]

Been testing https://github.com/gonetz/GLideN64/commit/d5a0f20098b838266485d211a5781e01a18dfec1

Glide64:

GLideN64:

Angrylion's:

I'm not sure this half-fix was a good idea because it makes games that use this shadow method look really, really ugly. Even the inaccurate hard black shadows are, IMO, preferable to these harsh black fuzzing things.

[gonetz]

I reverted my fix. Need to find another solution.

[olivieryuyu]

seems fixed