RGBE vs float HDR

im looking at HDR rendering, now, im wondering if i should use RGBE or float textures.

what are the pro’s and cons of each?

heres my list:

-less memory

-more work on shaders decompressing/compressing

-less work on shaders

-more memory

i’m guessing i will end up using floats as it would make things simpler and provide better quality, plus im guessing it can support an alpha channel also.

Have you also considered the DXT1 RGB + 16 bit greyscale method that Humus recommends?

You could also include alpha in this scheme if necessary…

Yes, since you’ll get filtering all the way back to R300/NV30, plus less storage space and bandwidth needed, I recommend that method over FP textures. Decoding is three ALU instructions. You may want to check the “HDR Texturing” paper that’s included in the latest SDK. It lists a whole range of different formats and encodings that you can use, with their pros and cons.