For linear polynomials, there's a bunch of algorithms for efficiently determining which voxels to test for collision (eg. [A Fast Voxel Traversal Algorithm for Ray Tracing](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.42.3443&rep=rep1&type=pdf) ). I'm having troubles though, searching for algorithms that work for any other case, such as a parabolic projectile arc under constant gravity. Are there any algorithms for that case, or am I stuck just trying to sample at a high enough frequency that only rarely will a projectile travel though a wall without getting detected.