That has to be it! I'm not at my computer now so I can't test it, but it fits exactly!
I thought that 2D and 3D samplers had their own "name spaces" so I didn't set the uniforms as those are the...

Great advice, thanks! I still don't get what's wrong, though.

I added a part that sets the color white if the starting point read from the 2D mask is smaller than a given value, and black...

Thank you for your response. Correct me if I'm wrong, but that seems to be about mipmaps and artefacts caused by discontinuities in the texture.
I forgot to mention that I don't create mipmaps, and...

Hello!

I have a weird problem with my shader.

In the fragment shader I'm reading data from a 3D texture in a for-loop until the correct alpha value is found, with a maximum number of iterations...