I just posted my Instructable at https://www.instructables.com/id/Creating-a-3D-Photo-Image-in-a-Hand-drawn-Arbitrar/ This openscad work consists of: 1. updated tracing of a colored line in a image, constructing the list of points along the line. 2. deciding if points are inside or outside of an arbitrary polygon. Well mostly arbitrary, no holes allowed. 3. mapping an image and cutting the image by the polygon, and 4.using the excellent nSplines library to construct a single polyhedron of the resulting polygon outlined image. Yes there are other ways to get this same result. But I wanted to do more with image processing beyond surface(). Have fun! Rich -- Sent from: http://forum.openscad.org/