This patch adds a function to BRL-CAD that generates a fully configurable section of c-channel.
Updated version of the patch:
Your patch was accepted and applied as svn r56152. Your named is credited in our AUTHORS file and will be included in the next public release of BRL-CAD.
Only issues I noticed seemed to be limitations on the parameterization of the c-channel. Didn't see a way to specify the width or height, only length. The bottom rounding was tangent to the interior wall, which meant it wasn't a smooth transition if there's any slope. Also, didn't seem like there was a way to specify the top rounding only on the inside lip. Basically, it's the difference between T1 and R1 in this picture:
Otherwise, all my testing went smoothly. Everything seemed to work mostly as I'd expected and inferred from the Usage statement alone, so very well done.
As this is now committed, please do base any future patch updates off of the latest SVN sources. Again, nice work!