Autodesk’s Daryl Obert with a look at using Motion Vector Passes rendered in Mental Ray Maya for adding motion blur in a post compositing application.
Learn how to render out a Motion Vector Pass using Mental Ray in Maya 2013, then comp the output images back together in Maya Composite
Daryl highlights some workflow issues that will come up when working with rendering multichannel EXR files with a motion vector rendering pass and multiple Render Layers in Maya.
There is always a bit of forethought needed to manage how the rendering pass system will work and what types of passes, mattes or contributions you need to generate for any given project.
This represents a great overview of using Maya’s Render Layer System for creating rendering passes for composites, and shows some of the concepts needed to navigate through some of the issues that arise when managing all the pieces for render passes for compositing the scene together so they will match the beauty pass.