GLOSSARY
Image motion blur blurs the object by creating a smearing effect rather than multiple images. It takes camera movement into account. Image motion blur is applied after scanline rendering is complete.
For most purposes, image motion blur gives a better effect than scene motion blur.
Tip: When blurred objects overlap, blurring doesn't work correctly and there are gaps in the rendering. Because image motion blur is applied after rendering, it can't account for object overlap. To fix this problem, render each blurred object separately, to a different layer, and then composite the two layers using the Alpha Compositor in Video Post.
Note: Image motion blur doesn't work for NURBS objects that are animated so their tessellation (surface approximation) changes over time. This happens when sub-objects are animated independently of the top-level NURBS model.