From: Scott Herod (herod++at++rtset.com)
Date: 03/03/2000 11:03:12
Hello,
I am looking at pfLayers as a way to handle not only
Z-buffer fighting but also transparent layer depth sorting
to avoid what I call alpha-cutting. I understand the DISPLAY
mechanism and while it does help with the Z-buffer fighting
it doesn't solve the alpha cutting.
STENCIL layering also appears to fix the alpha-cutting problems
( at a noticable performance hit to my 02 ) but am I correct that
it sets values in the stencil buffer as it draws each region and
tests for the higher layers. The problem is that my second layer
is only drawn when it is explicitly over the bottom layer. It would
be nice if I could also force it to draw when the second layer is
not over the bottom layer. Is that possible?
More details. I'm guessing that STENCIL layering happens as follows.
Draw the bottom layer writing appropriate values into the depth-buffer
and TRUE's into the stencil buffer. Draw the second layer by testing
the values in the stencil buffer and ignoring the depth buffer. Write
some appropriate values into the buffers. Repeat.
What I would like to do is draw the second layer if the stencil
buffer test passes OR the depth buffer test passes. Possible? Or
do I just need to do all sorting and testing myself?
Thanks,
Scott Herod
herod++at++rtset.com
This archive was generated by hypermail 2b29 : Fri Mar 03 2000 - 11:03:20 PST