multiple volumes used as AOV for main volume

[Jesper Rahlff]

I have a main volume that I want to render. however In that volume I would love to be able to merge other volumes into it and use those volumes as extra image planes. This means that my second volume should NOT show up in my beauty pass, but be available as an AOV. is this possible?

Right now I have it setup so I render the second volume separately, but I wonder if the other thing could be done?

[Pazuzu]

Hi,

Here is an example file to create custom aovs for different volumes, the workflow is a bit cumbersome because you can't reference the volumes directly from sops but from a geometry file. The main thing is to activate your hero container to sample the volume aovs.

I hope it helps you!

Thanks,

Alejandro

volumeAOVs.hip

Edited August 1, 2018 by Pazuzu

[Gorrod]

You can also use the "op:" expression (e.g. op:`opfullpath("../../yourVolume/OUT")` ) in the filename to direct to a sop, so you don't have to save your volumes/vdbs to disk first.

 

Edited August 1, 2018 by Gorrod

[toadstorm]

Here's another method just handling everything in the shader. The AOV volumes are just merged into the renderable object and multiplied against the Of output from the Volume Shader Core.

 

volume_with_aovs.hip

[Pazuzu]

33 minutes ago, Gorrod said:

You can also use the "op:" expression (e.g. op:`opfullpath("../../yourVolume/OUT")` ) in the filename to direct to a sop, so you don't have to save your volumes/vdbs to disk first.

 

Sorry but that's not possible! Because Mantra will not find the path to the node.

[toadstorm]

It's actually possible to use op:/ syntax to point at SOPs in a shader, as long as the SOP is the output (or upstream of the output) of an object listed on the Mantra ROP. If you don't actually want that object to render, you can add the vm_renderable flag to the container and set the value to 0.

[Pazuzu]

3 minutes ago, toadstorm said:

It's actually possible to use op:/ syntax to point at SOPs in a shader, as long as the SOP is the output (or upstream of the output) of an object listed on the Mantra ROP. If you don't actually want that object to render, you can add the vm_renderable flag to the container and set the value to 0.

Yeah I know! I was meaning that not directly, you need to tweak first to make it functional. Even when you tried to render that's what the command line tells you! I didn't explain my self correctly!

[Jesper Rahlff]

Cheers for all the solutions guys. I appreciate the time you spend on it