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Author Topic: Another vote for scattering vdbs / vray volume grids  (Read 871 times)

joconnell

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Another vote for scattering vdbs / vray volume grids
« on: June 15, 2020, 06:22:44 PM »
Heya folks!

I've done a lot of cloudscapes in clarisse over the years as it was fast to render volumetrics and didn't have memory issues. Chaos has fixed instancing of vdbs in vray next / 5 and so it'd be great if forest had support for the volume grid. My work around is going to be meshing vdbs, scattering with forest and then swapping to instances and replacing those with vdbs. It's a slow workflow though, do you think it'd be possible to support the bounding box of the volume grid for scatters?

Cheers!

John

Paul Roberts

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #1 on: June 16, 2020, 02:14:03 PM »
Hi John,

We'll take a look at this and see what can be done. In the meantime you can already select and scatter VDBs with Forest Pack (no need to mesh them first), but they won't render until you Instantiate them using Forest Tools. Not sure if that's any help for your situation.

Cheers,

Paul
Paul Roberts
iToo Software

joconnell

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #2 on: June 17, 2020, 06:58:49 AM »
Hmm, I did a quick check with a vray volume grid and the vray 5 beta build of forest, I'll do another check though!

Paul Roberts

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #3 on: June 17, 2020, 10:10:22 AM »
I should add that it won't look like it works, Forest can't read the mesh so there's nothing to display, but when you instantiate it, they are there.

Cheers,

Paul
Paul Roberts
iToo Software

joconnell

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #4 on: June 17, 2020, 06:44:11 PM »
Oh lovely!

Do you think it'd be possible to query the bounding box of the grid so we get some kind of idea how the scatter is behaving with the display set to box mode?

Thanks Paul!

link3d

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #5 on: May 12, 2021, 02:59:47 PM »
Hello,

I'm trying to scatter some vray volume grid clouds.
Is there now a possibility to render vray volume grid in forest?

Best regards.

Paul Roberts

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #6 on: May 12, 2021, 03:27:21 PM »
Due to some limitations in the V-ray SDK it's not possible to render VDBs while they're a part of a Forest Object. However, it is possible to scatter them with Forest Pack and then convert them to native instances using Forest Tools.

I hope that helps,

Paul
Paul Roberts
iToo Software

steve3duk

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #7 on: September 23, 2022, 12:39:22 PM »
Is this now possible? I was hoping to scatter animated VDBs over a large area and then offset and loop the animations relative to each other. Is this kind of control possible with Forest Pro?

Paul Roberts

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #8 on: September 23, 2022, 05:43:44 PM »
Hi,

It is now possible to scatter VDBs using Forest Pack you can see a little bit in this video about it: https://www.youtube.com/watch?v=zQ9IjXEbdSc&t=321s

From memory, I don't think the animation of VDBs they can be randomised since we can't sample them like normal geometry objects, but you could scatter several volume grids each with different start frame offsets (this is essentially what FP does internally for geometry)

Best,
Paul 
Paul Roberts
iToo Software

steve3duk

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #9 on: September 23, 2022, 07:42:06 PM »
Ok, that's great. I do have an issue though. The checkbox for: Non-geometric object is greyed out. Nothing will render.

Paul Roberts

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #10 on: September 26, 2022, 09:20:17 AM »
Hmm - that's strange. Are you able to check it before you pick an object from the scene?

Cheers,
Paul
Paul Roberts
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iToo

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Re: Another vote for scattering vdbs / vray volume grids
« Reply #11 on: September 26, 2022, 10:08:50 AM »
The non-geometric checkbox is greyed out because Forest already indentifies VDBs as non-geometric object. It's not necessary.

This checkbox is only to force standard objects to be handled as non-geom (instancing method is slighty different).
Carlos Quintero
iToo Software