In article <web.3f4d28bf8f004971d63a77300@news.povray.org>,
 "gramirosimancas" <nomail@nomail> wrote:

> >Actually, I don't think you will get any improvement using pyramid tracing.
> 
> Theorically you will get _full improvement_ (or _best results_).

You misunderstand the theory. By integrating analytically, you get 
results only limited by precision. But analytic forms of the 
computations will often be far more computationally expensive, and for 
some objects/textures, are simply not possible.

Intersecting a pyramid with a shape gives you a complex volume. Using 
this to render an image is tough. You would probably be reduced to 
tracing rays against the volume to find the silhouettes of the various 
shapes involved and approximate the average color seen. There is no way 
it would help with texturing, at least, not with anything like the 
texturing POV uses. It's useful for things like audio simulation, and 
probably for some specific highly accurate optics computations, but not 
for general image rendering. As a way for "perfect antialiasing", I 
think you're on the wrong track.


> In the 2d case where "pyramid raytracing" is used successfully in many
> vector drawing programs and render libs there is an alias removal bost
> while compared to bad libraries that do simple pixel sampling (equivalent
> to 3d raytracing).
> An example library that does this kind of antialiasing in the 2d world is
> http://www.levien.com/libart/

This is a *very* different case, involving much simpler mathematics. It 
has very little application to 3D projection onto a 2D image.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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