image sampling issue


I am facing a weird problem.

I render a scene and then copy it into an image. When doing this myself, with my own program, everything is fine, the image is beautiful. When I do the same for a plugin for a program (here graphite), the image is drawn with big pixels, like if I copied the scene in a smaller image.
Actually I’m pretty sure that I do exactly the same thing: the image sizes are the same (512*512), the used parameters are also the same (clamp_to_edge and linear min/mag filters), and of course I render with the same viewport/projection matrix and modelview matrix.

I really don’t know where to look for.

Any hints ?


Forget it, I found out what was the problem.

As usual it was easy and dumb: the faces used for the model are quads and aligned to axis, and the normals I had were only per-face normals which tended me to think I had a sampling problem and not normals issue.