Volume effects and parti_volume

[Maximus]

hey guys, i'm tryin to figure out how to produce a volumetric effect with parti volume and parti volume photon, but i just get a black render.
I dont understand how to assign those shaders at all, not using any lens shader on camera, just default scene, 0 ambience, 1 spotlight and a cube wich i assigned a lambert with those 2 shaders applied into volume port and volume photon port.

Can someone please point out how to use them? i dont understand, and the help is not really helping at all..

i remember there was a thread on xsibase someone made a good fog/volume environment with spotlights and some little cards in front of the spot for the effect?
cant find the post anymore...

any help would be appreciated..

is this shader broken? its freezing softimage as soon as i plug it into the volume port of the material.. i remember it was working..

been 5 hours tryin to figure it out whats happening.
Softimage always crash... using parti_volume.. can anyone confirm its broken? so i stop tossing time at it..or am I doing something terribly wrong here?

i've found a tutorial on parti_volume wich says I need to activate the "Auto Volume" option into Mental Ray global settings...
where is that parameter? i've checked Max and it has, Maya has it too but i cant find in Soft..

Thanks in advance for help

[Hirazi Blue]

Not sure if this helps:
As far as I understand this post in the Softimage Mailing list,
it's more of a case of wrong default settings, not so much bugged shader.

the parti_volume is a bit of a pain in the ass, if you render with the settings
as they arrive = long freeze and have to hard restart, some of the default
settings at 0, MR is not happy with.

The author of this post (Robert Chapman) adds a downloadable example model in which I assume the "correct" settings are being used.

[Maximus]

thanks Hirazi, i already saw that, but my main problem is i cant find some parameters..


quote from the help:

http://softimage.wiki.softimage.com/xsi ... photon.htm

min_level

The minimum refraction level at which photons are stored. This is handled differently for caustic and GI photons.

For GI photons the maximum level is set with the global option photon_refraction_depth.

Caustics photons storage is very different. It depends on more variables. First, the global option photon autovolume can be set or not. If it is not set then caustic photons are only stored after at least one refraction or reflection. If it is set, and the light source is inside the volume then caustic photons can be stored. If the light source is outside the volume, then caustic photons are only stored after at least one refraction or reflection.

Where is this global Auto Volume settings for photons? Because i saw it in Maya and 3ds Max, but i cant see where is it here..
i'm tryin to replicate Escape studios tutorial on how caustics pops up in a volumetric environment under a glass sphere, ive done it in maya in 4 minutes following the tutorial, i cant find parameters in xsi..

this one:

http://www.escapestudios.com/free-tutor ... aya-users/