Binary Space Partition (BSP) Tree

RayTreeIntersect(Ray ray, Node node, double min, double max)

{

if (Node is a leaf)

return intersection of closest primitive in cell, or NULL if none

else

dist = distance of the ray point to split plane of node

near_child = child of node that contains the origin of Ray

far_child = other child of node

if the interval to look is on near side

return RayTreeIntersect(ray, near_child, min, max)

else if the interval to look is on far side

return RayTreeIntersect(ray, far_child, min, max)

else if the interval to look is on both side

if (RayTreeIntersect(ray, near_child, min, dist)) return …;

else return RayTreeIntersect(ray, far_child, dist, max)

}