gg10@prism.gatech.EDU (Galloway, Greg) (08/30/89)
I need some help sorting out a slight conflict between two Siggraph
articles.
In [Carp84] Carpenter states that:
"The A-buffer belongs to the class of hidden surface algorithms called
`scanline'. The REYES (Renders Everything You Ever Saw) sytem, of
which the A-buffer is a part, is a scanline renderer, but scanline order
is not required by the A-buffer."
In [Cook87] it states that:
"The z buffer is important for two reasons. ..."
From this and some other references to z buffers throughout the Cook article
I get the impression that Reyes uses the z buffer technique and not scanline.
I'd like to implement a scanline rendering algorithm because of the ability
of the scanline algorithm to completely antialias a given line. I am planning
on antialiasing nearly horizontal lines and same polygons which might drop
out between scanlines by using Cook's stochastic sampling technique.
Does anyone out there have any insight into how either the Reyes or A-buffer
algorithms work? Cook, himself, told me at Siggraph that A-buffer was not
a part of the Reyes system. Anybody know any different?
References:
[Carp84] "The A-buffer, an Antialiased Hidden Surface Method", by
Loren Carpenter, Computer Graphics Project, Computer Division,
Lucasfilm Ltd., Computer Graphics (Siggraph proceedings 1984).
[Cook87] "The Reyes Image Rendering Architecture", Robert L. Cook, Loren
Carpenter, Edwin Catmull, Pixar, Computer Graphics (Siggraph 87).
Please reply by E-mail. I'll send summaries to interested parties.
Greg Galloway
Georgia Inst of Technology
gg10@prism.gatech.edu