View Full Version : Eye plane texgen

12-22-2005, 12:41 PM
I'm trying to create a shader that would do the same thing than an texgen using eye plane mode in regular OpenGL. For some reason the following shader function doesn't work...

void fnSpotTexGen(int nL)
vec4 vertEye2 = gl_ModelViewMatrix * gl_Vertex;
gl_TexCoord[nL].s = dot(gl_EyePlaneS[nL],vertEye2);
gl_TexCoord[nL].t = dot(gl_EyePlaneT[nL],vertEye2);
gl_TexCoord[nL].p = dot(gl_EyePlaneR[nL],vertEye2);
gl_TexCoord[nL].q = dot(gl_EyePlaneQ[nL],vertEye2);

If I hardcode gl_TexCoord[nL].q, I get "almost" the same results than regular OpenGL. Any clue on what's wrong with this texgen?

01-02-2006, 07:25 AM
Try the 3dlabs shadergen tool:-

...then, if the shader generated by it doesn't match the fixed pipeline, it's a driver bug.

08-07-2006, 08:57 AM
Hi I have the same problem. And I've used 3dlabs shadergen tool. The shader and the fixed pipeline image in the tool are the same. But when I use the shader in my app, the result is wrong. When I stick to fixed function pipeline the result is write. I suppose it is not a driver issue, because it is the same for nvidia and ati