Talk:Mathematics of glTexGen

Don't know if this is the right place for writing this, but I was just applying the maths mentioned in the article for a project I was working on, and I found out the GL_SPHERE_MAP calculations are not correct, for where it says:

reflectionVector = myEyeVertex - myEyeNormal * 2.0 * dot3D(myEyeNormal, myEyeNormal);

It should be:

reflectionVector = myEyeVertex - myEyeNormal * 2.0 * dot3D(myEyeVertex, myEyeNormal);

And where it says:

m = 1.0 / 2.0 * sqrt(dot3D(reflectionVector, reflectionVector));

It should be:

m = 1.0 / ( 2.0 * sqrt(dot3D(reflectionVector, reflectionVector)) );

I'm not an expert on the subject, but having checked the OpenGL reference pages and looking carefully at the glTexGen documentation, it seems the original formula posted on this page was not correct.