Question

I am trying to store an octree in a 3D texture in OpenGL for use on the GPU using Cg, from a chapter in GPU Gems 2 found here http://http.developer.nvidia.com/GPUGems2/gpugems2_chapter37.html. However the results I am getting are incorrect. I think this is because of how I create the octree.

In the appendix of that chapter, it says “If we bind the indirection pool texture (octree texture) in repeat mode (GL_REPEAT)…”.

Does this simply mean set the the filters and wrapping to repeat, or do I need to do something else? This is my code so far

glGenTextures(1, &octree_texture);
glBindTexture(GL_TEXTURE_3D, octree_texture);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_REPEAT);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_REPEAT);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT);
glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, WIDTH, HEIGHT, DEPTH, 0, GL_RGBA, GL_UNSIGNED_BYTE, octreeData);

Thanks for the help 🙂

Answer 1

The filters can’t be repeat, that will generate a GL error, only the wrap mode can be GL_REPEAT, and that’s probably what the book means.