Texture format (transparency glitch)

[Parovozik]

For some games textures without transparency where it should be. Maybe uses incorrect format textures? For example games as RDR (trees, grass), Midnight Club LA (grass), Naruto games (trees, grass), GTA San Andreas (vegetable, wires), MK vs DCU (trees, effects), Asterix at the Olympic games (effects) and more.

[Parovozik]

Here trouble with compressed textures DXT 4_5 which converted for Vulkan as VK_FORMAT_BC3.

/* k_DXT1                   */ {VK_FORMAT_BC1_RGBA_UNORM_BLOCK},
/* k_DXT2_3                 */ {VK_FORMAT_BC2_UNORM_BLOCK},
/* k_DXT4_5                 */ {VK_FORMAT_BC3_UNORM_BLOCK},

I tried replaced on other formats, and came to the conclusion that everything is correct here, and the error occurs already in the rendering (the error is that the alpha channel is not used). For example BC4 instead BC3 for DXT5 textures

[DrChat]

Hmm... Similar issue to Banjo Kazooie (xenia-project/game-compatibility#206)?

[Parovozik]

I see Banjo rendering correct now (remember screenshot with eggs) i will try replace format, but most likely here other format.

[Parovozik]

I tried Banjo. Eggs uses texture format k_8888. Alpha channel used but slightly glitch with close other obects and depend on view angel. Transparent turn on 1st egg and 2nd too but only one of them:

here is correct:

here is incorrect:

[DrChat]

Banjo Tooie's issue is that the game isn't properly enabling alpha tests. Most likely a JIT issue.

[LuismaSP89]

This issue is present too in Bayonetta

[D1SMBD1D]

Still present on DX12 in many games

[Triang3l]

Not a format glitch — currently kill shader instructions are totally ignored because they don't write anything to registers. The only reason why I'm not fixing it yet is because when I tried to do so, the Vulkan renderer started giving GPU crashes everywhere — the SPIR-V shader translator in Xenia doesn't really support this scenario.

[LuismaSP89]

Some transparency glitches solved in latest Xenia build, (Bayonetta plants for example)

[illusion0001]

Now fixed with commit https://github.com/xenia-project/xenia/commit/9dd62c1e1553cf89bb7e3c4779163ec404b9599f

[Triang3l]

Yes, alpha to coverage is implemented on Direct3D.

[Xupi413]

Forgive my ignorance, but how exactly can I fix this? I have been having this problem with gta iv and it is quite annoying. (i use vulkan)

[Triang3l]

Forgive my ignorance, but how exactly can I fix this? I have been having this problem with gta iv and it is quite annoying. (i use vulkan)

Alpha-to-coverage hasn't been implemented in the Vulkan backend yet, use Direct3D 12 for now.