FBO + Cubemap + Floating Point Textures...

OpenGL OpenGL: Advanced Coding
1

I want to do some RTT on a floating point cubemap texture, is this currently possible? I do not need 32 bits of precision, 16 would be fine, but I’m under the impression that in order to use floating point texture formats with an FBO, you need to have them be rectangular textures. Is that still the case? If so, what are my options? I only (currently) need one channel of the texture, if that helps. Thanks.

2

Yeah I would like to know what the limitations to the FBO texture types are also? As of now I did a search on the extension page for GL_LUMINANCE16F_ARB or any floating point texture type and found nothing… Would we need to use ARB_RECTANGLE? <- can’t remember the exact extension but with a OpenGL2.0 card do you need to use that extension if you use FP texture formats with FBO’s?

3

For NVIDIA boards the supported hardware tetxure formats are listed in the GPU Programming Guide:
http://developer.nvidia.com/object/gpu_programming_guide.html
Search for “texture format” tables.

The mapping of OpenGL’s internalFormat parameters to HW formats is described in this table:
http://developer.nvidia.com/object/nv_ogl_texture_formats.html

For texture rectangle vs. non-power-of-two support read this:
http://developer.nvidia.com/object/nv_ogl2_support.html

I can only recommend to have these PDFs lying around on the desktop along with the OepnGL 2.0 spec. :wink:

Not sure about the FBO implications.

4

Thanks Relic

5

Yeah, thanks Relic!