Motion Blur and Subdivisions

[Brian3D]

Hey Vray team!

Been doing some cloth animations lately and noticed if I put a simulated object into a subdivision surface (to have it a little smoother looking motion blur breaks. Would be nice to have this fixed at some point. The only work around I found is to not have it in a sub d.

Just wanted to let you know.

Thanks for all your amazing work on this program!

[daniel.kapsazov]

Hello Brian3D, Thank you for reporting this. I was able to reproduce the behavior on my end, and we will investigate it further. Meanwhile, I noticed that the issue only occurs when using Motion Blur from the Physical Camera settings. When Motion Blur is applied globally through Render Settings > V-Ray > Overrides > Camera, the calculation is performed correctly. You can use this as a workaround while we are looking into your report.

Example:

[daniel.kapsazov]

Hi Brian3D, a small addition to my previous answer: I was informed by colleagues from the Development team that there are two other ways to apply subdivisions to the cloth simulation while retaining Motion Blur.

Simply place the simulation tag on the Subdivision Surface instead of the nested object.

Example:


Using the V-Ray Geometry Tag

1. Add the V-Ray Geometry Tag to the object.
2. Enable Subdivision and OpenSubdiv in the tag.
3. From the OpenSubdiv tab, adjust the subdivision level to smooth out the geometry.
4. This approach ensures that Motion Blur will work correctly.

Example: