Afterburn and V-Ray

[charleyc]

can you try to seperate your AB into passes? maybe im doing something wrong. i want a pass where the AB shadow is on the ground but the AB isnt shown. then another where the AB volumetric is shown (environment pass) the environent pass works however i cant get the shadow pass to work

I am not sure how to make the shadow split work correctly in VRay to begin with, much less with AB, so I would still do it the old school way.

Make everything else white except the shadow. As the VRay Shadow automatically self shadows the atmospherics, an easy way to not have to mess too much with you AB/lights setup is to use the Explode Deamon with a color of white, a high multiplier (10 or more) and use the Replace Color Blending mode. Set your ground objects to have Matte properties within VRay Properties and you are good to go. Also, don;t forget to set your background to white. This will give you your AB shadow agianst a white background for you to do as you wish within the comp.

If anyone does know how to get the shadow pass to work well with VRay, I would be all ears

Edit: It might be worth noting that playing around with the color of your AB volumes and the lights can get you some great power within the compositor, you can use different colors to create images for selections to isolate different qualities of the volumetric effect.

[Da_elf]

no, your not getting it. i know how to do a shadow pass. the problem im geting is that i dont want the stupid cloud in the shot with the shadow pass. normally if i want an item to cast a shadow on the ground but that we dont see the item i would turn off "visable to camera" however you cant do that with AB. Aura used to do this perfectly. when you rendered g-buffer elements Aura would show up on the environment pass yet it would not show up on any of the other passes like GI, Shadow, etc

[charleyc]

I do not believe I am following you. You mean you want to see the entire shadow, even what would normally be occluded by the object or in this case the AB effect?

[Da_elf]

exactly. in the case of something i recently did i had a tower and a particle system going around it like a snake. the particles were set to size0 and used for the AB atmospheric effect. i wanted to have the tower on one layer with all of its passes (diffuse etc) and one pass i wanted was the shadow of the snaking smoke on the tower (without the actual smoke in the shot) then i wanted the smoke on another layer so i could have fun with the smokes color in post.

[charleyc]

This can be done. Set up a scene as if you were going to do a shadow pass (white background, matte objects...).
-Set the AB density to .01
-in the Shadow Parameters of the Light, set the density to a value that gives the desired shadow amount (200 or so seems pretty close to the standard density).

This should give you a shadow only, the AB volumes will not be visable (or at least not enough to matter)

[galagast]

I can't recall where I read about this, you could probably try to use and add "Shadow" under the Render Elements. It might render it separately since it will only get the shadow data. Although I'm not sure if it will work with vray, haven't tested it.
Hope this helps

[charleyc]

I can't recall where I read about this, you could probably try to use and add "Shadow" under the Render Elements. It might render it separately since it will only get the shadow data. Although I'm not sure if it will work with vray, haven't tested it.
Hope this helps

This does work great for the scanline, but Render Elements is not supported by VRay. It has its own setup for this Split G-Buffer. I have trouble getting the shadow pass to work at all, so it may be possible with VRay/AB if someone knew how.

[instinct]

The newer builds have full integration with MAXs renderelements so that shouldnt cause trouble soon (atmo pass, shadow pass etc)

Thorsten

[charleyc]

The newer builds have full integration with MAXs renderelements so that shouldnt cause trouble soon (atmo pass, shadow pass etc)

Thorsten

That will be nice

[Syclone1]

Thanks again for the awesome input guys, Im 98% there on getting the powers that be to make the switch to V-Ray here

BTW - Are there any animated samples out there with using AB and V-Ray?

-dave

[charleyc]

Here is a quick test with very low sampling (notice the shodow edges and artifacts).

http://www.charleycarlat.com/Tests/A...-CloundMan.avi
-Uses latest Divx