Wheels, motion blur and motion vectors

[DickKickem]

You can move wheel rotation to vertex shader, instead of doing it as an object. That adds certain difficulties, such as complications with normal maps and added shader costs, however it also opens you a way to precisely control how much rotational blur you get independently from rotation speed using previous frame switch. I’m using this technique for fast rotating gears and generally it can be applied to wheels. Here are comparison shots for a cog, doing 12 revolutions per second:

Can you share your setup?