Orchid XP v7 wrote:

> However, a ray typically intersects a sphere in two places. POV-Ray
> generates both points of intersection because you might need them both.
> (E.g., if the object is transparent, you'll want to trace a ray out of
> it. If the object is involved in CSG with other objects, the "back"
> surface might actually be the first visible surface. etc.)

Ok, but I guess that you can still handle all cases with an intersection
routine that only returns the point in front of the ray?

1. If the object is transparent, you first enter the object and then exit.
2. In CSG the same applies: you still have to first enter all the
participating objects to calculate the outcome.

So this is not something that is mandatory but a convenience?

Post a reply to this message