Nicolas George <nicolas$george@salle-s.org> wrote:
> Tu find the closest object for a pixel, it is necessary to compute the
> intersection of the light ray with all objects in the scene, so raw
> ray-tracing will definitely not gain time with that regard. To gain time, it
> is necessary to use techniques of elimination, using some sort of
> hierarchical bounding boxes for example.

  I was comparing POV-Ray to OpenGL, not some naive 100-line raytracer
to OpenGL.

> I would not be surprised if modern implementations of OpenGL also had
> techniques to prune irrelevant objects.

  Nope. It's too difficult of a task.

  Some game engines try to reduce the number of polygons to render with
techniques like portal polygons etc, but OpenGL itself doesn't have anything
like that. And even those techniques used by game engines are of no help
if all you have is a big bunch of spheres (inside the field of view) and
nothing else.

-- 
                                                          - Warp

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