Steps to reproduce:
- Launch Blender 2.53 beta.
- Add a new empty scene.
- Add a cube, cut a hole into the top.
- Add a solidify modifier.
- Place a camera inside the cube.
- Add a new world datablock and enable environment lighting.
- Render the image.
See the pixel artifacts in the attached image. The .blend file has been attached as well.
Disabling anti-aliasing makes most of the artifacts disappear, but depending on the camera angle and the image size, bad pixels still occur occasionally. Full sample anti-aliasing does not fix the problem.
renderbug.blend (466 KB)