How to load multiple Texture

How to load Multiple Textures?
Some of them are just lookup table I will use int teh fragment program.

Just use glTexImage2D with the current multitexture target set using the glActiveTexture call. Binding subsequent to your load should also work on the active texture.

in fact
what I am trying to do is use one texture as an lookup table.

so 1st.
color1 = Texture(r,s, t)
then I use the alpha value of color1 as the index of to find color on 2nd one dimension textures.

I use cg…
can I direct use color as the index to lookup at the another map?

Yes, you can. I have no idea how to do this in Cg, but I use nvparse for texture shaders. But since cg is only a layer on top of OpenGL, there is also a way to do this in Cg. I use the “dependent_ar” texture shader to use the alpha value of a texture unit to look up a value from another texture. I configured texture units as follow:

tex0: a decal texture (texture_2d(); )
tex1: lookup texture (dependent_ar(tex0); )

Texture unit 1 uses the alpha and red channel of texture unit 0 as (s,t)-coordinates to look up some value. There are more dependent texture shaders for 1D and 3D textures. Check out the NVidia OpenGL spec.

[This message has been edited by mako (edited 07-27-2003).]