View Full Version : displacement problem


glowz
01 January 2004, 06:08 PM
ok...my RENDERMAN/MAYA question... I try to get SSS on a torus. It works but when I put a displace map, appear some holes. I explain it:

I create an Ensemble, inside Surface a put a SwissArmy for the SSS. It works right. Inside Displacement(Ensemble), I put a "Simple Displacement", with "0" Bound, Do displacement "on", Use Shading Normals "on", Kb "0.1" and inside Displacement a Brownian, with a "WorldPoint" mainfold.

Any help? I think it could be a normal problem

Manu

Mauritius
01 January 2004, 05:40 PM
Why do you switch the shading normals on at all -- this is only needed for polygonal geometry.
A displacement bound of 0 will also create errors anyway, from certain camera angles. Maybe your spots are related to this. Try switching the SSS of and see if they are still there (heuristics for beginners).

.mm

glowz
01 January 2004, 06:40 PM
Ok, thanks... just one thing, I use a polygonal geometry...

Mauritius
01 January 2004, 07:05 PM
Originally posted by glowz
Ok, thanks... just one thing, I use a polygonal geometry...
This is a very bad idea in the first place if you're using a REYES renderer.
If there aren't very imperative reasons to do so (I can't think of any in case of a torus), use a higher order geometry like NURBS or Sds.

.mm

stew
01 January 2004, 07:39 PM
Since objects made from polygons do not have a continuous surface, it can easily happen that displacements create holes.

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