Ray voxel intersection

Question

I want to test for an intersection of a ray with a voxel field.

I could naively crawl through the voxel field by calculating a ray-box intersection with the edge of

Answer 1

I believe the octree-algorithm does what your asking for.

Answer 2

Here's an implementation of Bresenham's in 3D. It's in matlab; if you don't speak that you can see a C implementation here.