James Whiffin takes a look at Premultiplication in Alpha Compositing and takes a look at how a 3D application such a Maya goes about creating alpha images by premultiplying the alpha. Check out the tutorial for Understanding Premultiplication in Basic Alpha Compositing here.

In this tutorial we’ll learn what premultiplication is, when we need to premultiply and unpremultiply, and how we can use this knowledge to solve matte processing issues

Understanding Alpha Premultiplication is an essential tool for creating and understanding compositing and can be used to solve matte issues that may arise when compositing. As Premultiplication is a composting mode of expression for compositing in general, James demonstrates premultiplication in After Effects, and also shows the same demonstration in NUKE.