Svend Tang-Petersen (svend++at++digi.lego.com)
Sat, 12 Sep 1998 11:37:03 +0200
A quick guess would be that this is a problem often occurring in
database modeling
namely z-fighting (z-buffering).
It occurs if you have modeled polygons which are exactly or almost on
top of each other.
The problem then is when the scene gets drawn that the distance to the
two polygons is the same
when you take the precision of the z-buffer into account.
So when you're drawing the scene the color which gets chosen is
depending on the drawing order
of the polygons and the round off error/comparison with the depth value
already in the z-buffer.
This can give the effect of seeing one or the other polygon at random,
thus the flickering.
There are a couple of ways to get around this:
a) Never model polygons that are exactly on top of each other, but have
a small offset
between them.
b) In perfly try to change the range of the z-buffer, by moving the
Near clipping plane out
and the Far clipping plane in.
--Svend Tang-Petersen, MSc
Silicon Graphics Stationsparken 25 2600 Glostrup Denmark
Currently:
LEGO, wiZards Kloevermarken 120 7190 Billund Denmark
This archive was generated by hypermail 2.0b2 on Sat Sep 12 1998 - 02:36:55 PDT