Re: [rp-ml] CSG correctness. (LONG!)

From: Adrian Bowyer <>
Date: Mon Dec 11 2006 - 19:25:03 EET

Todd Pederzani wrote:

> Your description seems to be targeted at slicing the objects. Have you
> given much thought to how support generation (for the RP systems that
> require it) would be affected?

The beautiful thing about CSG is that it solves this problem in one line of
code. The support at level Ln is equal to Ln+1 - Ln. You do that calculation
in a loop from the top down, then build from the bottom up...

You need an offset calculation too, which fortunately is also trivial in a CSG
representation (for a polyhedral object at least - keep the CSG expression the
same; offset each linear primitive blindly; the result is always clean with no
lines crossing each other or other horrors associated with a line-segment
polygon representation). With such an offset function you can easily program in
unsupported overhangs at specified steep angles and so on.


Received on Mon Dec 11 18:18:03 2006

This archive was generated by hypermail 2.1.8 : Tue Jul 21 2009 - 10:27:52 EEST