I''ve been messing about with multitexturing a bit in OpenGL, specifically applying a repeated detail texture to a lower resolution landscape texture. At the moment, I can only get the detail texture to work when it is the same format as the landscape, which means I have to store a geryscale image as 24bit colour. This seems like a bit of a waste to me as I only want to modulate the landscape colour by the greyscale value. Is there anyway of doing this? Also, the detail texture is making the landscape a lot darker as I''m using GL_MODULATE. Is there any way of making values over 128 in the detail texture brighten the landscape texure? Finally, is there a function similar to glInterleavedArrays() that supports multitexturing because at the moment, I have 3 OpenGL function calls per vertex This signature has intentionally been left blank.

MODULATE will always darken
perhaps u wanna use GL_ADD
though prolly what u want to do can only be achieve with one of ther combine extensions eg GL_ADD_SIGNED_EXT
either that or calculate the texels manually

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search google
also try nvidia and www.opengl.org

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