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StefanAlbertz
09-09-2009, 12:28 PM
Can anyone point me to a source (dvd, tutorial, book, forum) where i can get information about volume rendering particles with:
1. mentalRay + detail shadows
2. renderman / 3delight (rayes)

Im fascinated that one get so much resource about modeling, texturing, rigging .. but when it comes to particles, the amount of information gets very low.

Thanks in advance !! :)
Stefan

StefanAlbertz
09-09-2009, 07:53 PM
one solution (for shots without motion blur):

mental ray with raytraced shadows on the leading light. Using particleCloud with small radius, low opacity and tons of particles (>500.000) i get nice fine structures. But in combination with 3d motion blur this blows rendertimes up into skies.

rendermaniac
09-09-2009, 09:56 PM
Air http://www.sitexgraphics.com/ has pretty good volumetric support, but I don't know of any exporters that support it.

The best volumetric renderer I know of is Houdini's Mantra http://www.sidefx.com/. And it has a really good interface for creating volumetrics.

Simon

noouch
09-12-2009, 11:12 AM
3D motion blur will be slow on volumes no matter what. The fastest solution though would probably be a micropolygon solution like RenderMan/3Delight or Houdini's Mantra (not that it would be fast, but faster than raytracing anyways).

A good reference for Renderman (regardless of what you're doing with it) is this here:
http://www.amazon.com/Advanced-RenderMan-Creating-Pictures-Kaufmann/dp/1558606181

I've personally had great experiences with Houdini for volume rendering. For example you can render the particles as metaballs, which you can assign a volume shader to.

What's wrong with velocity blur? In most situations you could get away with it.

Crocodilian
09-16-2009, 08:21 PM
Im fascinated that one get so much resource about modeling, texturing, rigging .. but when it comes to particles, the amount of information gets very low.

Because 99 times out of 100 you're going to "fake" particles with a sprite-based solution. Not only are the render times a fraction of a physical volumetric render, you've got much more control over the look of the scene-- this stuff is visible in realtime, with a good application supporting a good OpenGL card. Compare that to the painstaking tweaking of a "real" volumetric render . . . there are some Houdini guys who do nothing but this, and can make it work, but its far from "everyday chops".

In production, particle FX generally are distinct from hard CGI, that is, a director may want a "bigger explosion" (somehow, no one ever asks me for smaller explosions!) or whatever. So you'll see particleFX more often done in compositing packages, and there's abundant info. Take a look for example, at the tutorials for Trapcode's Particular, here:
http://www.trapcode.com/products_particular.html

That said, I do know of one excellent general purpose text with a lot of information about Particle Flow in 3DS, Pete Draper's "Deconstructing the Elements". Must-have if you're a 3DS user, highly recommended even if you're not.

StefanAlbertz
09-17-2009, 12:26 PM
For soft wispy smoke effects, i love sprites also - but my problem is getting anything looking volumetric with shadowing into sprite-particles. Is there a hidden secret?

pptc
10-05-2009, 12:21 PM
Try afterburn-Maya technique with fluid.
http://petershipkov.com/development/overburn/overburn.htm

In prman 15, some new technique with volumetric rendering coming, hope is must be fast and good.

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