From the course: NUKE NUGGETS

Unlock this course with a free trial

Join today to access over 22,400 courses taught by industry experts.

010 The unpremultiply operation explained

010 The unpremultiply operation explained - Nuke Tutorial

From the course: NUKE NUGGETS

010 The unpremultiply operation explained

- [Voiceover] Hi, this is Steve Wright, welcoming you to this weeks Nuke Nugget, premultiply and unpremultiply demystified. By the way, this week there are no exercise files. If mishandled, premultiply and unpremultiply operations can introduce dark edges around your composites, so you need to understand them to avoid adding problems to your comps. A lot of folks find the whole premultiply unpremultiply story very confusing, so in this video, we'll see exactly how it works. Oddly enough, the source of confusion is mostly due to the unfortunate history behind the choice of its confusing name, premultiply, so here's the story. In the early days of CG, they originally had, you know, slow computers and not very smart software, so they actually rendered the CG element first, as the RGBA layer only, with no alpha channel, so all of these pixels, even though they might have been semi-transparent in the final analysis, were rendered at full color. Then they would render the alpha channel…

Contents