I did a quick test and the blur seemed to look good in MR on a simple cube spinning on a moving cube hierarchy. Be sure you don't use 'offset' in the MB settings or the wheels or they may look like they are coming out of the wheel wells. Check the transforms on your 'centers' on the wheels and all the parents for weirdness. If something weird is based on the parents, one way out of this is to plot and then use that motion on the wheels. Also, perhaps playing with the 'rotation order' may help, I would make sure that the spinning axis is first on the list.
-manny|SI support From: [email protected] [mailto:[email protected]] On Behalf Of Arvid Björn Sent: Tuesday, July 17, 2012 10:20 AM To: [email protected] Subject: Re: Car wheel motion blur Thanks, I tried your suggestion, but there's nothing wrong with the parenting. It is related to parenting, but that's not where the problem lies. It works fine with deformation motion blur with the exact same center of rotation, so that proves that the problem is in how transformation motion blur is being evaluated. When evaluated per point with a global vector, everything's fine. I wish I could force MR to do that even though I'm not actually deforming anything. On Tue, Jul 17, 2012 at 1:56 PM, Alok Gandhi <[email protected]<mailto:[email protected]>> wrote: Most probably the motion samples are creating an arc due to parenting. What you need to do is to check this is take the fcurves and scale them quite a bit. This will allows you to see in "slo-mo" the trajectory of the wheel as it moves along. If you see the undesired arcing then I would suggest changing the parenting so the center of motion is at the center of the wheels.
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