View Full Version : MR motion blur

03 March 2004, 12:35 PM
Im rendering a referenced character with mental ray, Maya 5.01, and "Exact" motion blur.

Im getting this warning message:

Warning: (Mayatomr.Scene) : lowerJacketShape: shapes are not equivalent, no motion vectors computed.

..and no motion blur is applied to the lowerJacket obj. Anyone know what this means and how to fix it?


03 March 2004, 12:46 PM
The warning means your objects are changing topology between frames (ie. they have more or less polys from one frame to the next). This is not in the tesselation of mental ray, but in the description of the mesh/nurbs/what-have-you itself.
This can sometimes be the result of using construction history and say, for example, creating a makeNurbsSphere and then changing the # of isoparms from one frame to the next. Other operations like geometry reconstruction, nurbsToPolys, etc. can cause similar problems depending on settings used.
Solution: don't do that.
If you have to do something like that, you should bake all the frames and turn it into a blendshape, with the base being the object with more faces. That way you will have a consistent # of faces all along your animation.

03 March 2004, 01:13 PM
Thanks gga. Youre right, there was some history on that one - a polyAutoProj and a polyTweakUV node. Didnt know these influenced the topology though...


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