Hi all,

We are having motion blur issues when importing scenes into solaris. Our scenes are saved out as usd from Maya. When imported it all works well however to maintain correct unit scale we scale the scene down by 0.01. This sometimes generates incorrect and exaggerated motionblur in the camera. I can't see why this would be expected behaviour as the relation to the objects in the scene is identical. Has anyone encountered this? And perhaps have a handy solution or advice ready?

We are currently using Houdini 20.0.653

/Many thanks in advance

camera scaling causing problems during render used to be a common issue in the past (at least in renderers that use camera space) until Mantra Implemented vm_removecamerascale property

I'm not sure if Karma or renderer you are using supports something similar, but if not and if it's really the camera scale causing the issue (since you said only sometimes) you may need to remove it by compensating for camera's full world scale

Yes, USD has reintroduced this nuisance. One easy way in Solaris to remove the scale is to use a parent constraint with the parent set to “/“ and have only scale checked.

Yeah its odd. Im expecting it to be the transforms being scaled as that is the node Im using. Nothing else. Either way it seems placing a cache node behind the scaling fixes the problem so all good for now i guess.

I'm experiencing the same problem now but cache doesn't seem to fix it. As soon as I scale down the camera the motion blur goes nuts. Cache lop seems to make the transformations of the camera completely different so not sure if that will work. Anyone had success any other way?

I spoke too soon. Cache lop might work if I put it after the transform. I misinterpreted what 'behind' meant. Running out a test now.

I found that the motionblur lop will also fix the problem for us. So no need for the cache lop.

I have been struggling with this issue and the suggestions weren't working in Houdini 21. They helped somewhat but I could tell the motion blur was still extreme. Caching camera scale etc. didn't help/ The one thing that has worked is, rather than using a Transform LOP to fix the camera scale, fixing the scale in a Camera Edit LOP with 'Prepend' selected AND overriding the camera's sampling in the same node.