Triangle intersection

Dickinson, John John.Dickinson at
Thu Jan 11 09:27:27 PST 2001

I have recieved a couple of answers directly and I thought other might want
some of the references I got.  Note that the trick is to do this
efficiently, something I forgot to say as I have to do it for many such
pairs of triangles.


-((Insert standard disclaimer here))-|---  Ray's Rule for Precision ----
John Kenneth Dickinson, Ph.D.        |   "Measure with micrometer;
Research Council Officer  IMTI-NRC   |    Mark with chalk;
email: john.dickinson at         |    Cut with axe."

Please have a look at 
    M. Held (1997): 
    ``ERIT: A Collection of Efficient and Reliable Intersection Tests''. 
    Journal of Graphics Tools 2(4):25-44, 1997. 

Good luck with your project.

--martin held

if they are known to intersect, just walk around triangle A until
it pierces the plane of B inside B, call that point pA.  same for
B wrt A, call that pB; then the segment you want is just pApB.


Tomas Möller. A fast triangle-triangle intersection test. Journal of
Graphics Tools, 2(2):25-30, 1997 

              A Fast Triangle-Triangle Intersection Test

                                    Tomas Möller
                                  Prosolvia Clarus AB
                                   tompa at

     This paper presents a method, along with some optimizations, for
computing whether or not two
     triangles intersect. The code, which is shown to be fast, can be used,
for example, in collision detection

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