Weird artifacts while rendering

Hello everyone, I’m relatively new to blender and have encountered some odd artifacts on one particular object in a scene. It seems to be some kind of darkening that occurs along the tiles that Blender uses to break apart a frame while rendering.

I’ve checked for overlapping vertices, but there were none to remove. I also tried recalculating the normals as well as flipping their direction. It’s just a simple cube that is actually sitting a minute distance away from the wall behind it.

As you can see in the pictures, it occurs both with and without any materials or textures applied. This is driving me nuts. Hopefully it’s just something simple I’m overlooking. Any help would be appreciated.

https://lh6.googleusercontent.com/-nKG-BWV3sUU/ThJH2Zs6i7I/AAAAAAAAACo/6E48AcKIbwg/Problem.jpg

https://lh6.googleusercontent.com/-ZL_glvD7LnY/ThJH2RrKiEI/AAAAAAAAACs/naXSrDtdiP0/Problem%2525202.jpg

Whatever is behind the wall, it may be close to it to the point where you’re getting a certain amount of Z-fighting, which occurs when two different faces are so close to each other that the Z-buffer does not have enough precision to render them properly.

Move the faces a little further from each other and see if that eliminates the problem.

It appears that there was some z fighting involved. I moved the back face of the sign away from both the front face and the wall, and saw no more artifacts on this or any other frame. I initially figured that as long as no faces overlapped each other that there wouldn’t be a problem. Would this be a bug then? Regardless, this fixed the problem. Thanks!