Arnold vector blur pass? Can't get it to work.

[Anonymous]

I am using a demo of max 2019, and Nuke 9.0 v5 for comping.

Trying to get a simple sphere out with a motion vector pass for vector blur, for testing purposes.

I understand that with Arnold, I have to create an AOV channel and use it in Nuke for vectors. I see the motionblur channel in Nuke but it's empty. What might I be missing?

[timh5D75Z]

Turn on motion blur in the render settings, but override the camera's shutter duration to be instantaneous.

https://docs.arnoldrenderer.com/display/A5AFMUG/Motion+Vector

[mikinik]

it doesn't work for me too.