什么时候我需要停止在八叉树中划分八分圆？

Question

I'm implementing octree data structure. In octants i store triangles. So question: When i need to to stop dividing octants in Octree? I think about max depth or number of max number of triangles in octant, but how i can calculate this values?

Answer 1

A good rule for many circumstances is to subdivide a box if the number of triangles in it is more than twice its depth in the tree. This ensures that:

1. The total space consumed by the tree is at most proportional to the number of trianges;
2. The total time spent traversing down the tree is at most proportional to the number of triangles you'll have to directly process in the target leaf; and
3. You can still go deep when necessary to decompose a tight cluster.