Rendering RBD alembic cache as layer (contribution)

[JayAims]

Hello VFX wizards!

I am trying to render out a sim with an RBD alembic animation from maya inside my houdini smoke sim.

I can render the scene just fine but my question is with object contributions. in lights you can add contributions that basically layer the exr file with direct lighting, indirect lighting, C, ect, for each light. Can you do this with objects as well? 

Because in my shot the object swirls around the smoke and has the smoke visible in front of and behind it.

I want to be able to essentially render out the RBD object that is spinning as a silhouette on its own layer that comp can add the actual textured object into nuke but still have it in the center of my sim.

Is this possible in houdini? *see attached for the LQ take of the shot*

 

smokeRender.v3_LQ.mov

[anim]

to render smoke with holdout for your object, either check Matte Shading checkbox on your burger object or alternatively put that object into Forced Matte parm on Mantra ROP and your smoke to Candidate Objects parm (or just to Force Objects and make Candidate empty)

then just comp it on top of separate render of your burger object

Edited June 3, 2016 by anim

[Guest tar]

Sounding like a perfect job for Deep comping?

[anim]

1 minute ago, marty said:

Sounding like a perfect job for Deep comping?

 if you have insane amount of disk space and plan on tweaking the object animation without having to resim/rerender the smoke, then by all means, otherwise I would still suggest good old matte

[JayAims]

11 hours ago, anim said:

to render smoke with holdout for your object, either check Matte Shading checkbox on your burger object or alternatively put that object into Forced Matte parm on Mantra ROP and your smoke to Candidate Objects parm (or just to Force Objects and make Candidate empty)

then just comp it on top of separate render of your burger object

I understood every word of this. lol. Sorry just excited that im understanding the lingo of Houdini!

Alright! ill put this into use!

Thanks Tomas!

[6ril]

nice smoke fx !