motion blur on instanced geo

We have points with velocity that we transfer to the packed object instanced on them. Even if we velocity blur on the geo node ticket it will add the velocity blur with the geo blur if its read with path/to/object/$F4.bgeo.sc. I expect it to only pick up the velocity from the attribute like when rendering points.

for example path/to/object/$F4.bgeo.sc renders incorrect but path/to/object/1001.bgeo.sc renders correct

In the example here the points are animated in Y. but we only want the velocity blur when check on the geo node. Is there a way around this or if this should be fixed?



moblurPacked.zip (55.5 KB)

V-Ray only do this if the point count is changing
if the number of points is the same, always use the positions for moblur

This is different then how mantra behaves. If you choose velocity blur on the geo node it assumes thats what you want to use and not both. Problem for us is that we have points saved in a frame range wth $F4 so there is no real way for us to get correct moblur here.

Regards Alexis

hello again! So we encounter a bit of issues with this and we cant match our motionblur except with velocity. But only velocity and not geo samples. Is there someway to force this?

Try setting nsamples 1 in object properties may be it’ll do what u want…

didnt work with nsamples. But if i turned on rayserver instancer it only read the velocity which is what i want. So found a workaround for now

@LeoYfver With Rayserver, do you get velocity AOV? In a test on our side, it’s disappearing.

That one got fixed by Andrei in the latest nightly, thanks!