I have a strange problem with rendering using the Emit property and getting some strange artifacts. I’m using Blender 2.49b 64-bit version. Admittedly, I’m new to Blender, so perhaps this is a “feature” rather than a “problem”, and perhaps there is a better way to do it.
What I’m doing is this: I’m making a large space station with many, many windows. Instead of modeling each one of a couple thousand windows, I’m making an object with an alpha pattern to “punch holes” in it for the windows, with another object behind it with the Emit property to provide light that shines through the windows.
For the most part, everything looks very good. The problem comes when I use a camera angle that puts one portion of the station over another portion that has these lighted windows. The edge of the overlapping portion has an artifact that looks as though the light emitted from the overlapped portion is shining on it as though there was no other object between them. The part of the overlapping portion with the artifact is line-of-sight between the camera and the emitting object. See the photo below (the artifact is enlarged in the pink box):
In this example, the “mushroom” top of the station is partially overlapping the “stem” part of the hull. Where the edge overlaps the stem, there is the artifact. Note that it is not quite the width of the stem – that is because the emitting object inside the stem is slightly smaller in diameter. The length of the artifact exactly matches the diameter of the emitting object.
I could understand if the artifact only appeared where there were windows, but it’s acting as though the entire windowed object was not there. I’ve tried a number of variations, including turning on/off various settings like shadeless, raytrace enable, shadowbuffers, etc, on the emitting object, the windowed object, and the overlapping object. Nothing seems to make the artifact go away.
I’m supposed to be rendering an animation with this very soon, so prompt assistance would be greatly appreciated!