Ok, not arbitrary, but interesting! I created a design to map an image onto a subset of 3D shapes. I posted my material on Instructables, https://www.instructables.com/id/Photo-Images-Mapped-on-Arbitrary-3D-Shapes-in-Open/ I did depend upon the excellent nSplines library by Parkinbot (Rudolf Huttary) on thingiverse, https://www.thingiverse.com/thing:1208001/files I learned a lot about images, and have done additional work to represent images on opaque surfaces which can be 3D printed. This work does generate an openscad feature request: I would love to be able to grab the greyscale pixel values from surface(), without an object being created! Then I could drop my python script. I am happy to discuss my methods. Rich -- Sent from: http://forum.openscad.org/