CompuServe Messages

On occasion, I have run across a model that creates flickering faces. I wish I could be more specific, but that is exactly what they are. I single face on a surface will flip from lighter than the surrounding area to darker on a 2 to 4 frame interval. This creates a very distracting flicker when I play back a finished animation. I have noticed this phenomenon in both R2 and R3. In my recent experience, I decided to find out what the problem was (using R3). Changing the shading mode, textures, blurring, and filtering method produce no solution. The object in question is an L-shape created from the 2D shaper, then lofted (it is used as a brick wall). When rendered, a single triangular face flickers intensly for no reason. By removing all smothing groups from the object, the problem vanished. If I auto-smooth it again, the problem comes back. I have noticed this with some boolean models too, but only recently found a work-around with the extruded L-shape. This is not a pressing problem since I have found a work-around. However, I was wondering if anyone knew of what conditions might predictably cause this phenomenon so that I may avoid it in the future. Any thoughts are appreciated. — James —