Mark Christianson wrote:
Maybe I'm barking up the wrong tree, but when I have encountered this it is usually caused by periodicity checking and can be cured by turning it off. What the exact cause is I have no idea. It occurs under certain conditions (hitting a point inside the set, plus some unknown factor) with certain fractal formulas (my "gravijul" being one). <<
This behaves differently than periodicity checking. Once the bug occurs, EVERY pixel is returned the same from that pixel on until the end of the image. If you change passes mode or image resolution, every pixel in the new image will be the same. If you do a save immediately upon hitting the bad pixel (there may only be 1 or 2 such pixels in the whole image!), exit fractint, and then restart with the saved image, the image will continue normally. Lee