As Richard said, you just need two keyframes. I just set a key on frame 1 and another on frame 5. That way, I’ve got a couple frames I can pick from to get the right motion.
Just grab the “thigh” and move it, and voila, you’ve got a quick and cool motion blurred kick for your football/soccer player
You will have to check the “Motion Blur” checkbox in the render settings of course. “Motion samples” is the value defining the quality of the blur ( quite similar to the “pixel samples” value when you’re using depth of field ).
Just know that a high value implies a higher motion blur computation. I strongly suggest to render your scene without the moving part, then re-render the moving part on a background image ( using your previous rendered image as a background maybe ).
Eliminating most transparency/reflection/refraction will speed the process up because the motion blur computation is done on the whole scene and not just the moving part. It will really affect your rendertime, even with a value as low as 16. It does look amazing anyway and it is a welcome feature. You can really get creative with it.
The “motion amount” value allows you to easily tweak the amount of motion blur. The amount of blur is caused by the movement between two frames. The higher the movement/translation/rotation, the stronger the blur. Lower values will lower the motion blur amout while higher values will accentuate it.
I’ve got an example but it is from an unreleased product promo so I can’t show it
BTW, it is interesting to note object motion blur has been implemented but not camera blur. You can still emulate camera blur ( blur induced by the translation/rotation of the camera ) by grouping your whole scene and moving it…