Add dynamic and scene support about three-mesh-bvh HOT 1 CLOSED

Plan

• Create an Octree class to represent the scene
• Keep tree up to date when objects in the scene
• Provide basic node types that can be inserted (for objects, meshes, spheres, etc). Leaves can be oriented bounding boxes.
• Allow for inserting octtrees recursively, leaving the tree whole if it's the only node in tree. Split it up into its child nodes in the parent tree if it simplifies the traversal complexity.
• Cache transformed rays per mesh / obb that needs to be traversed so we don't have to transform the ray over and over again
• This means that the BVH nodes can live in the tree alongside the rest of the scene and be updated with minimal effort.

TODO

• How do we detect if nodes have updated? Manually mark them? Manually check matrix differences?
• Should the octtree be maintained separately from the scene? Theres no way to really know if nodes are removed or inserted into the scene, and we only care about the children.

from three-mesh-bvh.