Question about texture mapping


I have a question about texture mapping in my program.
I was able to implement Projective Texture mapping correctly in which I load an image and use that as a texture for projection.
The question is that depending on where my camera is or in other words when the texture is out of range [0,1], the texture repeats.
In order to handle this, I used glTexParameteri with GL_CLAMP on both s and t. It seems working but now, another question is that it will look something similar to this:

I want my texture to show only the lower left without having those vertical or horizontal stripes…
So something like this:

So I am using GLSL to compute projective texture coordinate and use texture2DProj to draw it.
Is there anyway I can do this? Could someone help me on this?

Thank you so much!

Maybe you can manually set all texels in the border of the texture to black?
Or set them with max transparency.

Set the clamp mode to GL_CLAMP_TO_BORDER instead and specify a black border color.

Thank you so much! That’s what I wanted it and it worked perfectly! :slight_smile: