Motion Blur - distorts Geometry - VRay 5 1.3 - 3DSMax 2021

[CLF73]

Hi There
We are having problems in our animations when rendering out deforming objects (bend, twist, skin etc.) with camera motion blur.

Is this a know issue, and is there a fix in the pipelines?
See pictures and sample scene in attachment.

With MB

No MB


VRay Version

[fixeighted]

Works fine here, though I am on '22 and build 00001, so maybe there is some difference between the builds, if that helps in any way.

[CLF73]

Thank you for responding fixeighted.
Just to be clear, did you download the sample scene and did a test frame 550?

I haven’t tried it on our max 2022 setup, but I feel quite confident it would persist in this scene.

The scene is rendering in RTX mode, but CUDA doesn’t make a difference.

[fixeighted]

Yeah I just opened the file...did a render reset to clear some warnings but it rendered fine, although I did not use rtx, which I'll try as soon as this render finishes.
Though if you say you get the problem occurring using cuda then it won't likely change anything.
Maybe it's the build....I don't get any update alert so is it a nightly build?

Anyway, I can always see if it persists under my 21 version. Might be tomorrow though

[fixeighted]

Ok, yes it happens with RTX if I just open the file and render. You can solve it by upping the geometry samples from 2 to an arbitrary correct amount for any given scene...around 10 seems to work in this simple case.
What is strange is that for me, CUDA works fine with the default 2 samples, so I have no technical idea what is occurring but assume it is RTX-specific.
Hopefully problem solved in any case....for the moment

[Paul Oblomov]

Current ray tracing Nvidia is also going through a new form of ray tracing introduced with Ampere in the form of hardware-accelerated motion blur in RT. - I suspect this one. Tho, I'm not a developer.