I'm done implementing Moller's tri-tri intersection routine. It gives you the location of where each triangle edge intersects the line of intersection between the 2 triangle planes:
Really you get the point location in the form of t values along the (really big) purple ray shown above. So you can tell if the triangle intersects if the t values are overlapping..?
That's what the paper says. But I can show you scenarios where the t values are overlapping, but the triangles don't intersect:
So I can't seem to figure out which edge value to discard.
The original paper is here: http://fileadmin.cs.lth.se/cs/Personal/Tomas_Akenine-Moller/pubs/tritri.pdf