If I understand correctly, the grid optimization speeds up ray tracing because we only have to test for intersection with objects inside the grid our ray traces over. This reduces the number of intersection tests we need to do because it reduces the number of objects to check. This is only efficient if we can quickly find which grid sections we need to look at, and this is where the 3D DDA ray traversal algorithm comes in to play.

If I understand correctly, the grid optimization speeds up ray tracing because we only have to test for intersection with objects inside the grid our ray traces over. This reduces the number of intersection tests we need to do because it reduces the number of objects to check. This is only efficient if we can quickly find which grid sections we need to look at, and this is where the 3D DDA ray traversal algorithm comes in to play.