Using Motion Blur

Motion blur is ideal for adding subtle motion based on accurate tracking of elements, however in extreme cases the tracking causes inaccurate blur and even causes the blur edge to curve in on itself.

Having many points close together, could also cause in accurcies.

To remedy the inaccurcies, keyframe the blur settings.

Motion blur is a great time saver when on needs to add that very subtle blur / lag of a knee bouncing to the beat of music but the normal edge offsets work better on extreme blur. In most cased it should be possible to combine Motoion blur with the normal edges to find a combination that works.

As described in the *monet *guide ( :
[Layers / Motion Blur - pg 94, current version]

Motion Blur
These controls allow you to create motion blurred mattes. Click on Apply to switch on the feature. You can then choose the *Source of Motion *with which to drive the blur either from the Track (the default) or the Contour. If no layer keyframes exist on a specific layer, and Link Contours to Track is on, it makes no difference whether Track or Contour is selected as the Source of Motion. However when dealing with layer keyframes there may be an advantage to using Contour as *Source of Motion *as it will achieve more detail in the blur, since it computes the blur independently at each point on the contour. Please test to find which setting achieves the most desired

*Please note: *when a layer is linked to tracking data by activating Link Contours to Track, and Motion Blur is applied, then the tracking data drives the motion blur regardless of which option is selected for Source of Motion. Selecting Track as *Source of Motion *computes motion blur for all points on the contour as opposed to computing the blur independently at each point on the contour as is the case when selecting Contour as Source of Motion.

When a layer is not linked to any tracking at all, selecting Track as *Source of Motion *will result in no motion blur, regardless of whether any layer keyframes exist. The value below the Apply button is used to scale the size of the blur relative to the size of the motion vectors. The default value 0.25 is equivalent to the camera integration time equaling ¼ of the frame time.
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