In this tutorial, we will learn how a 3D application such as Maya creates alpha images by premultiplying. To do so in software like Photoshop or Illustrator one must first create the image with transparency and then add an additional layer for each channel which is why it’s called “premultiplication.” In James’ informative video about Understanding Premulitipation at Basic Alpha Compositing , he shows us what exactly goes on behind closed doors when creating these masterful pieces!
In this tutorial we’ll learn what premultiplication is, when to prepremultiply and unpremultiple. This knowledge can help solve issues with matte processing!
Understanding Alpha Premultiplication is an essential tool for compositing and can be used to solve matte issues that may arise when working with complex graphics. A simple understanding of this cinematography mode will save you hours in post-production time, creating the perfect composite shot! James demonstrates premultiplication on after effects along with NUKE’s application also showing how they work together seamlessly between programs.