Tested in Maya 2011
VRay build : 12851
Fast moving cameras alongside fast moving objects are not calculating motion blur properly when sampling outside current frame. Basically if VRay has to cross over and sample blur within a different frame number than the current it doesn't calculate correctly. It appears there is a built-in offset between Maya's motion samples and VRay's.
In a simple test scene where a sphere is translating from x=0 to x=100 over 24 frames, and a camera is animated to do exactly the same, it is really apparant. With no moblur, the sphere stays at a fixed position in the render. With moblur enabled an interval center of 0.5 and duration of 0.5, the sphere remains fixed at the center with not apparant blurring.
However, set interval center to 0 and the sphere renders as a blur.
I have found any combination of
if Interval Center < 0.5 then (Duration > Interval Center x 2) is broken
if Interval Center > 0.5 then (Interval Center + Duration x2 ) >1 is broken
Often it is really useful to set your interval center to zero to conform to a matchmove, so that your track remains true and you only add blur around it. We just finished a sequence where the 'world' was itself moving, even though the objects were to remain static in frame, and consistantly ran into this issue.
VRay build : 12851
Fast moving cameras alongside fast moving objects are not calculating motion blur properly when sampling outside current frame. Basically if VRay has to cross over and sample blur within a different frame number than the current it doesn't calculate correctly. It appears there is a built-in offset between Maya's motion samples and VRay's.
In a simple test scene where a sphere is translating from x=0 to x=100 over 24 frames, and a camera is animated to do exactly the same, it is really apparant. With no moblur, the sphere stays at a fixed position in the render. With moblur enabled an interval center of 0.5 and duration of 0.5, the sphere remains fixed at the center with not apparant blurring.
However, set interval center to 0 and the sphere renders as a blur.
I have found any combination of
if Interval Center < 0.5 then (Duration > Interval Center x 2) is broken
if Interval Center > 0.5 then (Interval Center + Duration x2 ) >1 is broken
Often it is really useful to set your interval center to zero to conform to a matchmove, so that your track remains true and you only add blur around it. We just finished a sequence where the 'world' was itself moving, even though the objects were to remain static in frame, and consistantly ran into this issue.
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