I have been working on my tri-tri intersection for my first little project the past week, but there are a few things I don't understand. For your reference I've been using THIS document for my implementation: http://www.acm.org/jgt/papers/Moller97/tritri.html#TRITRI My apologies for the fact it's code. I hope you can understand the bit. Anyway, I perfectly understand the plane equation and how it's used for "coarse" detection. The part below is beyond me though, where the sides are checked (I presume it's checking the sides for intersection) if they are inside the other triangle. He completely lost me where he started to take the cross product of the two normals (/* compute direction of intersection line */) Can anyone help me out with this, link me to a less technical article of fast tri-tri intersection, or give an explanation of the approach? Thank you! ______________________________ If idiots could fly, I would be a space-shuttle. [edited by - Structural on December 18, 2002 6:33:33 AM]

Hey,

Here''s a few resources that may shed light on the subject:

http://www.gamasutra.com/features/20000210/lander_01.htm

(gamasutra registration is free)

http://geometryalgorithms.com/Archive/algorithm_0105/algorithm_0105.htm

http://www.realtimerendering.com/int/

And, also, the following is an improved version of the 1997 code you''ve been using:

http://www.ce.chalmers.se/staff/tomasm/code/opttritri.txt

Also, check the forum FAQ question on point-in-polygon tests (near the bottom).


Graham Rhodes
Senior Scientist
Applied Research Associates, Inc.