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Couple of questions rgrd 3DFX emulation

Posted: Fri 14 Jan, 2022 5:39 am
by MrMe85
Just have a couple of questions regarding the current 3DFX emulation.

1) I notice that mipmapping is nonfunctional, and has been for a long time. How hard would it be to implement this in the future? I think emulators like Dosbox-X and possibly ECE have this functionality, so would some collaboration to have this for PCem be possible?

2) I also notice that Voodoo 1/2 emulation places a significant load on PCem compared to Voodoo Banshee and Voodoo 3. Any reason why this occurs?

Re: Couple of questions rgrd 3DFX emulation

Posted: Fri 14 Jan, 2022 9:43 pm
by leilei
There's mipmap emulation, it's just that the LOD calculation isn't perfect. Try r_colormiplevels 1 in Quake3, they'll show.

What's missing is emulation of the optional mipmap dithering (which selects mip levels using a 2x2 dither matrix to make a rough trilinear look, but it isn't very compatible with multitexturing)

Re: Couple of questions rgrd 3DFX emulation

Posted: Sat 15 Jan, 2022 6:44 am
by MrMe85
leilei wrote: Fri 14 Jan, 2022 9:43 pm There's mipmap emulation, it's just that the LOD calculation isn't perfect. Try r_colormiplevels 1 in Quake3, they'll show.

What's missing is emulation of the optional mipmap dithering (which selects mip levels using a 2x2 dither matrix to make a rough trilinear look, but it isn't very compatible with multitexturing)
If this is the case, how hard would it be to make improvements on these fronts?

I notice that there are significant graphical distortions in a number of games that utilize mipmapping either in DirectX or glide. For instance: Mechwarrior 2: Mercenaries (Direct3D) has some weird horizon and ground blurring issues whenever mipmapping is turned on.. Mechwarrior 2: 31st Century 3DFX appears to have problems with textures in the horizon. Tomb Raider 3dFX completely loses its graphical fidelity whenever mipmapping is turned on with very weird funky texturing up until mipmapping is turned off.

Re: Couple of questions rgrd 3DFX emulation

Posted: Wed 16 Feb, 2022 11:12 pm
by sndwv
Is it possible to 'force disable' mipmapping for Voodoo and / or Voodoo2 on the driver level or with 3rd party drivers?