Turning motionblur off on camera causes geometry to not be in the correct position

[frame48]

Good morning!

We've been experiencing this random issue in Solaris where if an object has point velocities, and then we decide to turn off motionblur on our physical camera, the object shifts in position and doesn't match the position of the object in the viewport. We've been setting our shutter open and close to -1 and 1 as per suggested on other forum threads.

Using the latest nightly for vray 6 (but also tested on some machines with vray 7) and houdini 20.5.445

Only fix weve found is to completely delete velocities from the objects but that prevents us from using velocity vectors in comp.

[daniel.kapsazov]

Hello frame48, Apologies for the late reply.

A fix concerning motion blur was introduced in our nightly builds in February. Could you test whether the behavior is still reproducible with one of our latest nightly builds?

If the issue persists, I would appreciate it if you could share a simple scene with us for further investigation.

[frame48]

Unfortunately it doesn't seem fixed in:

V-Ray for Houdini number:22910 hash:0c268b3 from 22 Mar 2025 01:42
V-Ray Core 7.00.12 [3b5b5b67] from 11 Mar 2025

The steps to reproduce are pretty simple, have an object with point velocities, have render geometry settings forcing object to use velocity blur, turn off motionblur on vray physical camera properties.

The only workaround so far to be able to render without motionblur is to in addition to setting motionblur off, also setting the cameras shutter open and close values to 0. If the the shutter values are anything else the entire object shifts its position at rendertime.