On 20-Sep-99 Jeff Slutter wrote:
> Hi,
> I'm currently porting Descent 3 to Linux using Mesa as the OpenGL
> renderer. Using the same source code as the Windows version except for the
> initialization and any other glx specific things I have gotten it all ported.
> However, there seems to be some issues with the perspective texture mapping.
> I'm not quite sure if this is on our side, Mesa or maybe even glx (I'm using
> the NVidia glx X-Server for my TNT and the one for Matrox for my g400), but
> remember that this is the same source code as the Window's version.
Have you tried compiling using linux/Mesa's 3Dfx driver? I realize you already
have a glide version working/in-the-works for Linux, but both the Matrox and
NVidia drivers are _considerably_ newer and less polished than the 3Dfx one.
The FX driver has about 1.5 years of seniority over the other drivers and has
been much more thoroughly tested/debugged. Testing against this driver will at
least isolate whether your problem is with the chipset-level drivers or Mesa
proper.
Joe
> I've
> also talked to John Carmack at Id on how they do their texture mapping
> coordinates for Quake (since Mesa and Quake get along quite well). Where we
> are different is that Carmack uses OpenGL for transformation and clipping,
> while we don't. I have found a hack of sort which improves the texture
> mapping for D3, however, it still isn't fixed.
> It would be a great help to me if I could get in contact with someone to
> maybe help work out these problems. At the end of this email I have included
> the source code to how we calculate our texture coordinates.
>
> Thank you for your time,
> Jeff Slutter
> Outrage Entertainment
>
> our texture map coordinate setup code: (done for each vertex, pnt)
>
> float texw=1.0/(pnt->p3_z+Z_bias);
> texp->s=pnt->p3_u*texw;
> texp->t=pnt->p3_v*texw;
> texp->r=0;
> texp->q=texw;
>
> My hack was to remove the *texw for the s and t coordinates...that fixed 95%
> of the problem, however, any polygon clipped on the screen suffered
> perspective issues.
>
--
Joe Waters ([EMAIL PROTECTED]) Aegis Simulation Technologies
Shoot stuff. Break things. Impress your friends.
We can help. Play BFRIS. http://www.aegistech.com
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