I have found that Carrara's Motion Blur is excellent, but as Mark points out, it does hit majorly in render time. The animatable procedural (and texture maps -- movies more precisely) textures will also blur due to the process Carrara employs to create the blur. For the time-hit, though, I've found, as Mark mentions, that it's much quicker, if not quite as accurate, to do the blur in post. For animations, I move into AfterEffects and apply ReelSmart motion blur (a plug in from re:vision effects). It's quick and looks good in motion. I'm pretty sure ReelSmart is also available for FCP, Premiere Pro and other products. Hope that's helpful. Dex