Liquid sim motion blur problems

[lukepenry]

I have a viscous liquid sim with velocity turned on, but when i enable the motion blur through the 3ds max physical camera it only renders correctly on the first frame.

The frames after produce strange artifacts. it seems to have something to do with the geometry samples but no matter how low or high i put them, it still produces artifacts.

i have checked the documentation and can't see anything i'm not doing.

Any ideas?

Thanks,

L

[Svetlin.Nikolov]

Hey, which Phoenix version do you use and is this Max or Maya? Does it also reproduce with the Chocolate quick setup preset from the toolbar for you?

[lukepenry]

Hey, i ran some of the presets and they didn't have artifacts, and that's when i realised the only difference was i had been adding a relax modifier on mine. that is causing the motion blur to go crazy. do you know of a way around this or if this is a known issue?

This doesn't happen on the first frame i render on, only the frames after, i have to render 2 frames to see the crazy result.

using Vray Next update 2 on 3ds max 2020

Thanks!

[Svetlin.Nikolov]

Ohhh, this is a setup we've never tried. Let's see if I can blow it up here....

[Svetlin.Nikolov]

Hey,

Simulated a Tapwater and a Chocolate toolbar Quick Setups for 100 frames, put a Relax modifier over the simulators, a sun and sky and a V-Ray Physical camera and rendered sequence from frame 90 to 100, but could not break it. What are your values for the Relax modifier? Are there by any chance any other modifiers as well?

My guess is that something changes the number of vertices of the mesh and this breaks the motion blur...

[lukepenry]

My relax value is set to 1, and my iterations to 5.

Yeah it's strange, especially since i could go through one by one and render each frame and then use the sequence but when i try to render it as a sequence, it starts going mad past the first frame. I am going to slow the animtion down and add the motion blur in post.

[Svetlin.Nikolov]

Yess, broke it here as well! Let's see now...

[Svetlin.Nikolov]

Ah, dang, gotta put my bigger glasses on. I've enabled only particle velocity but not voxel velocity when simulating, so now it's okay.

Would it be possible to send the scene over to support at chaosgroup dot com so we can check it?

[lukepenry]

Sure! i will send that over when i get a chance. thanks

[Svetlin.Nikolov]

Thank you so much!