Redshift Volume Motion Blur need Help!

[Litesound 0]

Hello people! 

I'm currently trying to render pyro exoplosion with the motion blur in Redshift and I didn't succeed with any of my aproaches. I tried Convert to VDB , and then Merge Volume in Velocity mode with the motion blur ON but nothing works yet. I found few HIP examples but they neather don't work. Is there anybody who ever did this? Too bad there's nothing about it in the Redshift official documentation too. Please help 

Edited February 6, 2020 by Litesound

[Howitzer99 21]

It sounds like the only thing you're missing is to enable "Use Velocity Grids" in the Geo node.  It will be under Redshift OBJ/Volume, then make sure that the naming matches your velocity volume, "vel" by default.

 

[Litesound 0]

Thank you Howitzer99

Just tried enabling 'use velocity grids' option and somehow motion blur doesn't seem really correct, see the pictures below. Is that okey that blur behaves like that? It makes smoke puffy, not blurry

Edited February 7, 2020 by Litesound

[DaJuice 51]

This is a known issue with Redshift. As in, motion blur on volumes does something, but the results are not accurate. From what I understand the devs are working on updating the volume tech to add support for things like multi-scattering, so hopefully we'll see a fix for this as well.

[Howitzer99 21]

Maybe try adjusting the Velocity Grid Scale, it's an option below Use Velocity Grid in the screenshot above, and might be more accurate than frame duration. At least until, if it is a bug that the devs are aware, and a proper fix is in place.

[Litesound 0]

Howitzer99 unfortunately Velocity Grid Scale does the same thing as a frame duration, the same fluffy result, which is dissapointing. So let's wait updation from devs:)

[Howitzer99 21]

What version of RS are you using?  If you can you share a file, it would help to debug.

[Jorge Medina 0]

Hi, the same problem here.

I think it should be somthing to be with the velocity data transfered to teh engine.

Dmitry, are you working in the the original world scale from houdini?

 

[olivetty 2]

MB on volumes in RS just doesn't work at the moment. It tries to "smear"/"displace" the volume using the velocity data but it's not great to say the least. Maybe there's something you can do to the data and render out some kind of motion vector pass or something? I don't know