Hi all, It seems that the sketch support in BRL-CAD is very buggy or perhaps not fully implemented... I would like to get an informed opinion on the status quo.
While wrapping the Sketch/Extrude/Revolve primitives in python-brlcad, I did some tests to understand how it works. The net result is that I barely managed to get any of the sketches I created to properly extrude or revolve... For the Extrude part, after a quick code check I concluded that support for NURB segments is not coded at all, they are simply ignored... also the CARC segments are buggy, some work some not. The Revolve primitive - I could not get it work with anything else than line segments. Even with those I'm not sure what are the requirements for the resulting shape to raytrace properly, for example it's not clear what happens with points on the revolution axis. It seems that the first and end points will be automatically closed with a disc even if they are not on the axis. Also some of the parameters are ignored, or at least it seems so, and others I modified but the effects were not consistent... I uploaded one of the tests I made, ray-trace revolve.s to see one of the failures: http://pastebin.com/kJppsgyK Generally where can I find some documentation of how it works in detail ? In fact I would go further and ask if the existing primitives would perhaps be enhanced by: * 3D path (to allow curves in space); * extrusion along a path -> this would cover both extrusion (linear path) and revolution (circular arc); It seems that other CAD projects implemented/discussed this: http://wiki.blender.org/index.php/Doc:2.4/Tutorials/Modeling/Curves/Extrude_Along_Path http://www.we-r-here.com/cad/tutorials/level_3/3-7a.htm https://github.com/openscad/openscad/issues/114 So what is the status quo in this area ? Is there any existing effort which is not already in the primitives code ? Implementing some of this could be an interesting GSOC project too. I would also like to have a stab at it but my attention is currently on the python-brlcad project and time is limited... Cheers, Csaba ------------------------------------------------------------------------------ Flow-based real-time traffic analytics software. Cisco certified tool. Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer Customize your own dashboards, set traffic alerts and generate reports. Network behavioral analysis & security monitoring. All-in-one tool. http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk _______________________________________________ BRL-CAD Developer mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/brlcad-devel
