I am mapping two textures to a polygon and blending them together. One is RGB and the other is ALPHA. When I choose the dimensions of the texture to the higher power of two I get odd shadows. When I choose the lower power of two it looks fine.
The shadow appears as if the alpha value on the opposite edge of the texture gets copied to the other side. I am using GL_CLAMP_TO_EDGE, but it doens’t help.
Are you using CLAMP_TO_EDGE on both textures?
Also, you’re un-clear about how you upload the texture data. If you’re letting something like GLU rescale the image for you, there’s no telling what that function will do. I suggest creating your textures yourself, using real powers of two. Rescale in Photoshop if you need to, rather than at runtime. Also, both textures don’t need to have the same size, but you probably already knew that.
[This message has been edited by jwatte (edited 06-11-2002).]
I use CLAMP_TO_EDGE on both textures and I’m using gluScaleImage. Unfortunately due to the nature of my application the size of the textures are user chosen or I would scale them in Photoshop. This shadow also occurs when I use gluBuild2DMipmaps.