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Pickman
11-02-2008, 08:23 PM
Hello guys, i'm working on an underwater following floze's tut and i can't seem to get the nice light beaming through the foggy atmosphere. I checked his workflow and light settings but can't achieve the same result.
I used a directionnal light to project the cautics in the color slot.
I used a sunlight and sky in my scene,is that the reason why i can't get a nice beaming?
the ref i would love to reach is here:http://i11.photobucket.com/albums/a165/TeriFitzgerald/Humpback_Whale.jpg
and this is my pic:
Gozer
11-03-2008, 10:59 AM
Not 100% sure but the workflows used for partiVolume in 2008 seem changed / bugged in 2009, i didn't get it to work whatsoever when i did some tests at 2009 release.
achoury
11-03-2008, 12:05 PM
hi
if you are using parti_volume shader in Maya2009 you have to connect the parti_volume into the Volume Shader and Material Shader of shading Group> Mental ray>custom shader

you can read this thread about ray marching in Maya2009 (http://forums.cgsociety.org/showthread.php?t=678056) for more info

/rachid
chriswaner
11-25-2008, 04:46 PM
Yes,

parti_volume appears to be having troubles in a number of ways in Maya 2009. Unless there have been more significant changes to 2009 than simply connecting the parti_volume to the mental ray material shader of the shading group node (and I can't claim that my search has been exhaustive), there also appears to be draw order problems as well.

Here's an image comparing the same scene in Maya 2008 and 2009.

As you can see, it is unusable as is. Could be that there is further information missing here. I'm not quite ready to call it a bug.
CGNotebook
10-25-2009, 03:20 AM
Heya Pickman -

In 2009 "auto volume" defaults to off, in 2008 it defaulted to on. You need to make sure it's switched on or the effect won't render - find auto volume under the features tab in the mental ray render settings.

step by step tutorial here:

http://cgnotebook.com/wiki/Mental_ray_volumetric_shadows_with_parti_volume_in_Maya

and info on tweaking the parti volume node here:

http://cgnotebook.com/wiki/Mental_ray_for_Maya_parti_volume

hope this helps!!