Vesa, Arjo,
Thanks, the wild guess turned out to be correct, great!
I hope I can come up with an interesting animation with volumetrics,
-Mark H
Mark,
your explanation indicates that you have undestood the volume shading process
correctly. Thanks for mailing a better explanation than mine.
Arjo, I'm sorry for using misleading terms! I should have written
'Coordinates' not position:) The Coordinates channel includes the examined
volume position. Changing it will make the program to compute shadows and
illumination in another 3D point. Changing Map coords channel only will not
change illumination at all.
Best regards,
Vesa
----- Original Message -----
From: Mark Heuymans
To: [email protected]
Sent: Wednesday, March 14, 2007 12:02 AM
Subject: Re: groundfog test project
Arjo,
Where's the chapter about meditation in the RS manual? I need it ;)
What I got so far:
- volume shadows without any form of randomization leads to banding
artifacts. In fact, I noticed that volume sampling of 200 produces pretty clean
results, but that's a bit too much (however: skipping the randomization code
makes the shader faster)
- randomization of the Coordinates (a different channel from Map coords!)
partly reduces banding but introduces grain. The problem is only partly solved
because the Map coords don't match position (Coordinates).
- the Map object takes care of this by re-computing Map coords from the new
randomized position. Turbidity and volume illumination are calculated from
identical positions inside the volume; artifacts are greatly reduced.
In this case, the Random function is used rather than a Noise object: it's
something completely different. Noise is a fractal pattern generator, Random
doesn't have any patterns or scale/frequency.
Nice tiles btw; in your example Noise is obviously the way to go, rather
than Random!
my 2 cts (I doubt it helps... hit me with a hammer if I'm missing the point)
-Mark H
