Hi, I am trying to make a simple projective texturing demo. I think it works correctly, but the problem is that the texture is wrapping, so it's being tiled across the surface. So, I tried this: glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP ); glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP ); This doesn't really work though, as far as I can tell... Although it does create the desired effect of making only one "tile" of my texture appear, the edges of the texture seem to continue beyond where they are supposed to end. It's a bit hard to explain, so here's 2 images- the one on the left is uses GL_CLAMP. EDIT: I also tried setting GL_TEXTURE_BORDER_COLOR to black, but the edges of the texture are still "bleeding". Thanks a lot! roos

You need to set the clamp mode to GL_CLAMP_TO_BORDER. With GL_CLAMP texture coordinates are clamped halfway between the texture and the border, resulting in your left image.

Edit: Just too late :)

Oh man, THANK YOU guys so much, it works fine now! It would've taken me ages to figure that out, because the documentation I was looking at said there was only GL_CLAMP and GL_REPEAT.

roos

Haha yeah, finding good documentation is kind of tricky. I have the OpenGL "Red Book" from college, but it's 1.1, so it's useless...

Anyways, I ran into another problem :/ When I render my projective mapping demo into a texture, the GL_CLAMP_TO_BORDER setting seems to get ignored. Through a bit of trial and error, I figured out that I could "force" it to recognize the setting by calling the following code at the beginning of each scene render:

cgGLEnableTextureParameter( texture );
cgGLDisableTextureParameter( texture );

Also, even when I was rendering the scene normally (not to a texture), it would use GL_REPEAT for the FIRST render, although subsequent frames would render properly. Anyways, my solution is alright as a temporary hack, but if anyone could point out what the proper way to do this is, I'd appreciate it!

Thanks a lot!
roos

[Edited by - roos on May 31, 2005 9:39:52 PM]