Moving segments colliding I need to check if the edges of two triangles will collide. I do an edge-edge check for each pair. One segment is stationary, while the other moves with constant velocity. The segments are not deformable( the position of the moving points will only change due to the velocity ).
I've tried doing some vector math myself, but had no luck. I found out how to check if two segments intersect and where, but they have to be coplanar, so I still need to know the exact moment along the velocity when they will get coplanar, and if that moment actually exists. If not, obviously, no collision happened.
 A: You can determining whether a point is inside a triangle by using barycentric coordinates $\lambda_i$: Point $\mathbf{r}$ lies inside the triangle if and only if $0 < \lambda_i < 1 \;\forall\; i \text{ in } 1,2,3$.
Choose the first triangle to be fixed and check whether any vertex of the other lies inside the fixed one.
A: I have found the right answer myself and decided to share it with the community. Maybe someone else will encounter this problem too.
By the way: Sorry, draks ..., but I didn't see your comment until today. Look at this picture, the second case: http://i.stack.imgur.com/NP29I.png
Okay, so here it goes:
If you have segments A1B1 and A2B2, the first immobile and the second moving with linear velocity, you can actually project A2B2 on the colliding plane: The segment A1P will be its projection, where P = A1 + ( A2 - B2 ). You will then get the plane normal by crossing A1B1 and A1P. If you know the plane coordinates, you can then calculate when, along the velocity, will A2B2 intersect that plane. Hope it helps others.
