Hymyly <chr### [at] hotmailcom> wrote:
> We are seeing more and more elements from raytracing being brought into the
> graphics cards. First-order reflections, shadows and procedural textures have
> existed for quite a while

  Note that those reflections which are rendered with graphics cards are
not physically accurate. The effect is the same as if the rest of the
scene was infinitely away from the reflecting object. The closer something
in the scene is to the object, the clearer the visual error. And of course
self-reflection is completely out of question.

  Also, that type of reflection has a quality/memory usage tradeoff: The
higher the quality of the reflection, the higher the memory usage. This
isn't so with raytracing, obviously.

  Many high-end renderers out there (such as, AFAIK, 3DMax) support
raytraced reflections for this exact reason: Because the scanline-rendered
reflections are not always accurate enough. Unfortunately it also means
that the more accurate raytraced reflections cannot be calculated with
the GPU.

  There are currently two distinct techniques in real-time hardware
rendering for calculating shadows, neither of which has anything to do
with raytracing. One is polygon-based and not suitable for mathematical
surfaces, the other is stencil-buffer-based, and suffers from the
quality/memory usage tradeoff.

  Procedural textures have advanced quite a lot with GPU technology, but
it's still limited to what the GPU shader language has to offer. For example,
if I'm not completely mistaken, looping and recursion is out of question.

> It is only a matter of time before the graphics cards will be able to generate
> higher-order reflections, as well as simple refraction and caustics. Simple -
> but convincing. If POV-ray doesn't keep up with these developments, staying a
> couple of steps ahead all the time, it will eventually die out.

  To me it sounds like hardware is still badly lagging behind in features.

  Extremely fast? Yes. Diverse features? Nope.

> I am not familiar with the concept of "brute-force rendering" but I like the
> sound of it. :P

  In layman terms it means that you might be able to get stunningly realistic
scenes if you have the proper BRDFs and can wait a couple of days for the
graininess to go away.

-- 
                                                          - Warp

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