Intersection of two circles

Hi. I need to find the interection of two co-planar circles. I looked thru onutil.ON_Intersect to no avail, and now I'm trying rhutil.RhinoCurveBrepIntersect, since one of my circles came from a sphere intersection with a plane. I'm having trouble with this function though.

1. Since the curve I'm supplying is an OnCircle, it is saying it can't cast that to OnCurve.

2. Tolerance - I understand the concept, but not any details.

3. The output could be curves or points, and the points are an On3dPointArray, but the other says OnCurve[] -- do the brackets mean an array or what?

Of course, if there is better function to do this, then these questions are kind of moot, but I'm still curious about them.

Thanks!!!

Replies to This Discussion

Permalink Reply by Chris Wilkins on April 7, 2010 at 10:27pm

I think that all I need to do is find the intersection of two circles using math instead of some built-in intersection methods. Any advice?
-Chris

Permalink Reply by David Rutten on April 8, 2010 at 3:18am

Yeah, that would be my advice. Don't try to use the OpenNurbs curve intersectors, they're way too top-heavy for this.

All you have to do is plug the distance between the two center points and the two radii into the Law of Cosines and you've got your angles.