Hi, this issue originally arose in a grasshopper definition where I was projecting thousands of circles on to a wavy surface, however, it appears to be an underlying issue with rhino’s intersection algorithm (or perhaps a mathematical problem with my particular surface). In the attached file, I have simplified the problem to a surface and a cylinder. When you run the “intersect” command, it generates only 3/4 of the circle on the surface. There are several points around this surface where this happens. Any ideas what is causing this?
131125 Project Bug.3dm (546.5 KB)