How do I wash out textures?

I’m making a UI that uses textured quads as buttons. When I hover over them, I want the textures to increase in “brightness” so that they appear somewhat washed out. GL_EMISSION only gets them up to unlit brightness, so how do I get them even brighter so that they appear somewhat washed-out?


One way would be to store two copies of every texture. One copy is the normal color, the other copy is “washed out” (done in some painting program or done algorithmically before your UI runs). Then you could blend the two textures together varying the alpha values of each to get the desired result. That is, to get the “washing-out” effect, you would have the normal color texture going from 1.0 alpha to 0.0 alpha, and the “washed-out” texture from 0.0 alpha to 1.0 alpha.

The down side is that twice the texture memory would be required.

Good luck,

[This message has been edited by hkyProgrammer88 (edited 05-21-2003).]

Oh ok… I was playing around with GL_MODULATE and specifying a polygon texture. I learned that I’ve basically simulated the effect of lighting by doing so … I’ll have to use a second texture… Thanks for your help.