衝突判定
That is, if the triangles are v 1 , v 2 , v 3 {\displaystyle {v_{1},v_{2},v_{3}}} and v 4 , v 5 , v 6 {\displaystyle {v_{4},v_{5},v_{6}}} where each v j {\displaystyle v_{j}} is a vector in R 3 {\displaystyle \mathbb {R} ^{3}} , then we can take three vertices, v i , v j , v k {\displaystyle v_{i},v_{j},v_{k}} , find a plane going through all three vertices, and check to see if this is a separating plane. If any such plane is a separating plane, then the triangles are deemed to be disjoint.
On the other hand, if none of these planes are separating planes, then the triangles are deemed to intersect. There are twenty such planes.
If the triangles are coplanar, this test is not entirely successful. One can add some extra planes, for instance, planes that are normal to triangle edges, to fix the problem entirely. In other cases, objects that meet at a flat face must necessarily also meet at an angle elsewhere, hence the overall collision detection will be able to find the collision.
Better methods have since been developed. Very fast algorithms are available for finding the closest points on the surface of two convex polyhedral objects.