hi.
I have a flip sim - basically the shelftool tank setup - which I want to export to Maya as alembic and render either with Arnold or Redshift. the problem is that whatever I do I can't get deformation motion blur to appear in any renderer.
I did that workflow before with different kind of Houdini sims and animations without any issues nor extra steps in Maya, so is there something different about flips? am I missing sommething obviouse? not a Houdini expert...

I've been trying for weeks so any hints greatly appreciated. I found some roughly related threads but none of those suggestions (e.g. custome attribute name or promoting v to vertex type) made any difference.
thank you!

how are you loading this into Maya? Using .ass or a .rsproxy, vanilla Maya, BF graph?

You really should not need much, especially with Arnold. Depending how you are loading this into Maya, you do not even need to promote anything.

Ideally if you can provide maybe a few frames of the cache it would be helpful.

Also what M and Arnold/RS version are you using?

thanks for taking interest.
I'm loading simply via Cache>Alembic Cache>Import Alembic
that's the way it always worked for me.
I can upload few frames and check exact versions tomorrow, but Arnold is probably up-to-date, while Redshift rather old, as I'm on a permanent license, and they don't sell those anymore I think. I'm focusing mostly on Arnold these days.
as for Maya 2022 for Redshift and 2024 for Arnold

Are you loading a mesh then, is not point data, right? I would probably go with .ass and see if that works, it should.

If not then I would just load it into Bifrost and that would solve the issue.

letslie
whatever I do I can't get deformation motion blur to appear in any renderer.

I dont know the semantics of Arnold or RS, but deformation motion blur is usually describing MB computed from mesh deformation and for that it needs to have consistent topology

Meshed FLIP usually has different topology for every frame so you may need to use Velocity or Acceleration MB and for that you need to include valid v or v and accel attributes on your geo

I appreciate your replies

tamte
Meshed FLIP usually has different topology for every frame so you may need to use Velocity or Acceleration MB and for that you need to include valid v or v and accel attributes on your geo

does that mean the default v attribute that I get is not enough? is the accel something else?

sepu
If not then I would just load it into Bifrost and that would solve the issue.

it does something, but I'm not sure if the blur is accurate. looks a bit messy, like it's intensity and direction varies too much.

Can you share a few frames of the .abc?
Yes v@v for the most part should be enough.

v@v is enough for velocity MB
For acceleration MB you would need additional v@accel or sometimes v@force is used, any attribute that stores correct acceleration

However to tell Arnold to use it you may need to specifically say that you want it to use Velocity or Acceleration MB instead of computing from deformation
https://help.autodesk.com/view/ARNOL/ENU/?guid=arnold_for_houdini_geometry_ah_Motion_Blur_geometry_html [help.autodesk.com]