Game Development Reference
Figure 11.4. Resolved stick collisions.
x 1 = x 1 + c 1 λ d ,
x 2 = x 2 + c 2 λ d ,
x 3 = x 3 + c 3 λ d ,
x 4 = x 4 + c 4 λ d .
The new position of the tetrahedron's penetration point p ∗ = c 1 x 1
+ c 2 x 2
c 3 x 3 + c 4 x 4 will coincide with q . For details on the derivation of the above
equations, see [Jakobsen 01]. The above equations can also be used to embed the
tetrahedron inside another shape, which is then used for collision purposes. In
Figure 11.5. Tetrahedron (triangle) embedded in arbitrary object geometry touching the
In the above case, the rigid body collided with an immovable world, but the
method generalizes to handle collisions of several (movable) rigid bodies. The
collisions are processed for one pair of bodies at a time. Instead of moving only
p , in this case, both p and q should be moved towards one another.