When the prof mentions the bounding box of internal nodes is the union of child bounding boxes, does that imply that they become non-square/cubic? Or is it somewhat of a loose union?
jgforsberg
I think for traversing the trees all bounding volumes need to be square else it would be very hard to find t_split and decide which children you should recursively search on. We can easily make the bounding volume cubic by finding the smallest cube that holds all the bounding volumes of the children. This just involves taking the minimum and maximum of the bounding volumes' coordinates.
dtseng
Agreed, it makes more sense that the bounding box of the internal nodes is also cubic. In the "BVH Recursive Traversal" slides it also uses "node.bbox," and bbox generally implies a box or a cube.
When the prof mentions the bounding box of internal nodes is the union of child bounding boxes, does that imply that they become non-square/cubic? Or is it somewhat of a loose union?
I think for traversing the trees all bounding volumes need to be square else it would be very hard to find t_split and decide which children you should recursively search on. We can easily make the bounding volume cubic by finding the smallest cube that holds all the bounding volumes of the children. This just involves taking the minimum and maximum of the bounding volumes' coordinates.
Agreed, it makes more sense that the bounding box of the internal nodes is also cubic. In the "BVH Recursive Traversal" slides it also uses "node.bbox," and bbox generally implies a box or a cube.