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TheMyriad
01-02-2003, 06:43 PM
Hi! Does anyone know how to use HILO textures for bumpmapping with Cg fragment programs?
I might be missing something here, but I can't get it to work on the FP20 profile. Reading the texture's rgb components just gives me 0's.
Thanks!

jra101
01-03-2003, 09:02 AM
With the fp20 profile, HILO textures can only be used by the DOT_PRODUCT* texture shader operations (i.e dot product 2d, dot product reflect, etc...). You can't directly lookup into a HILO texture using tex2D().

pbrown
01-03-2003, 06:32 PM
In the NV_register_combiners extension (which the Cg fp20 profile is based on), you can't use a HILO texel. You can only use them in certain texture shader operations.

In the NV_fragment_program extension (basis of the Cg fp30 profile), you can read and do math on a HILO texture. The same will be true using ARB_fragment_program (Cg arbfp profile) if you have a HILO texture.