Alembic mesh with velocity causing distortion in v-ray proxy.

[^Lele^]

Eheh, you didn't think they'd misbehave with me too, did you?
However, i think i may have you try something: scale.
They came in *very* small, and slightly off-origin.
Maybe that contributed to the problem?

p.s.: the left one is the ABC, and renders with moblur correctly, moving along the X axis.

[Mirko.Binyan]

Unfortunately Houdini works in generic units (everything is set to work based on that), and meters are the standard export measure. I have tried importing them in a Max meters scene, and also i tried exporting them 1000 times bigger and importing them in a mm scene, but the distortion is staying, so i don't think that this is a size related issue.
What do you mean with "it's rendering motion blur correctly on the x axis"? could you please show when the little cube is splashing on the ground? they should look like this (left is alembic, right is proxy)



edit: actually, by scaling up the mesh in Houdini and exporting with the same velocity attributes, i get less distortions, as the velocity effect is not relative to the object size and doesn't scale up with it. But it doesn't go away. It keeps distorting it even if less then before.

[^Lele^]

Duh, i was utterly convinced you exported me a single frame.
Ok, i see the distortion, but the two animations play at different speeds, and splash differently: they don't look the same to me.

Anyhow, i see it's Ogawa, will investigate further, and pass it on to the devs with some more details.
Edit: it's not the flavour, HDF5 does the exact same, with minor differences. And ofc, Houdini opens it without apparent issue. I've contacted the relevant Dev.
Thanks so much for the help, Mirko!

[Mirko.Binyan]

yep i have exported the alembic with a motion blur option ticked by accident, but it doesn't make a difference for the distortion.
Sounds good! Grazie Lele

[mirko_venturi]

Hi! it's me again - different account.
How did this progress? I'm very curious as I'm working with v-ray 5.3 and i see this happening again.
Was this solved in a more recent v-ray version?