The printing form is not readable by Scheme but is useful for diagnostics. After the intersection has been found and validated, this call fills in the rest of the ray structure. Smoothing calculations on the triangular meshes are performed here. The normal obtained from here is not necessarily of unit length. Only trees hold anything that needs to be marked, for now.
TRUE is returned only if the intersection is actually between the endpoints.
This call is passed as pointer to the octree subdivider. Additionally, global variables needed for the normal calculation are set from here. They are used by EvalWithPrimitive . No such globals are needed in the present implementation, though. The purpose of this is to set the scene IDs for all the objects on the scenes.