1. I have a png file with the height map, 500x500 pixels. 2. I load this png as a surface. 3. I intersect or union or diff this surface with simple cylinder. 4. I refresh the view in F5 mode and all is ok. 5. I press F6 button to create stl representation and my Openscad windows process starts consume all memory until the computer crashes. If I miss the 3 step and export the surface 'as is' than everything is all right. Could you give me some advice, how to use the surface in my model? -- View this message in context: http://forum.openscad.org/Crash-while-render-surface-with-CGAL-on-2015-3-tp12148.html Sent from the OpenSCAD mailing list archive at Nabble.com.

On 03/23/2015 04:52 AM, glebkudr wrote: > the height map, 500x500 pixels. Each of those quarter-million pixels produces at least half a dozen triangular faces, so that simple model might have a million surfaces, each with three vertexes. Each vertex requires a handful of floating point numbers, so ... For my 3D printed cookie presses and chocolate molds, I set the image resolution to 4 pixel/mm for molds around 40 mm. The 17 March 2015 version of OpenSCAD turns a 160x176 pixel image into an STL file in about 100 seconds. If you reduce your height map to 250x250 pixels, it *might* start working... -- Ed softsolder.com