hello, since in GLSL the modelmatrix is not available, i was wondering if it is possible to get it programatically from the gl_ModelViewMatrix and the "viewmatrix" which i would pass as a uniform?
if yes, how?
thank you!
+3
A:
You can obtain the model matrix by multiplying the modelview matrix with the inverse of your view matrix.
gl_ModelViewMatrix * myViewMatrixInverse
Can
2009-07-20 07:27:32
thanks, but that means that i have to calculate the inverse of the viewmatrix on the clientside and pass it as a uniform, right?
clamp
2009-07-20 08:31:08
@matt: afaik there is no built-in function to do a matrix inverse in glsl or opengl. so you have to code your own in either the clientside or the shader, the decision is up to you.
Can
2009-07-20 09:24:47
thank you! and the viewmatrix is the one i get with glGetFloatv(GL_MODELVIEW_MATRIX , ...);immediately after the gluLookAt(), right?
clamp
2009-07-20 16:49:49
yes, that's right
Can
2009-07-21 08:19:20