Multipass Compositing

Compositing shots in the feature film industry requires the artist to be able to combine many elements in to one shot. Shots that include computer generated elements, like animated characters, are rendered out of the computer in multiple passes. Each render pass focuses the computer on rendering a specific surface characteristic. For example, the computer might render out a pass that only draws the reflections or another pass might be devoted to the shadows the object is casting. Computer generated elements are often rendered this way to maximize the level of control the compositor has on the final image.

We need to combine all of these separate passes in After Effects. This technique is called Multi-Pass Compositing. Using blend modes, track mattes and color correction tools, we will explore the art of multi-pass compositing during this week's lecture and laboratory exercises.

Project Due: Week 15

Completing a Multi-pass compositing shot is a lot like solving a puzzle. We need to decode a stack of computer generated film plates and discover the correct combination to unlock the final image. Multi-Pass compositing is tricky, but if you look carefully at each render pass you will find the solution to the problem. Remember, render pass that are black and white are usually designed to be a track matte.

In addition to compositing all of the computer generated images together, you will also have to remove the green screen and set from the live action plate. I have included on this page an example of what the final composite should look like. Once you are finished, please render our composition using the H.264 codec. Please ensure your project includes the following required elements before you complete this assignment:

The fantastic folks down at Hollywood Camera Work have developed an excellent training module on green screen effects. The raw green screen footage and finished example can be downloaded from their website. check it out!

Or, you can download the assets for the homework here:

After you have saved the project file on your personal external storage device (like a thumb drive), please upload your After Effects Project File (.aep) and your rendered Quicktime Movie (.mov) to the F-15 Flyover dropbox on D2L.

Before you upload your files to D2L, please ensure your files meet the following naming conventions:

Project Due: Week 15

Multi-Pass compositing requires the artist to analyze all of the provided elements and discover the correct sequence of layers that produces the final image. One tool that we can use to help composite all of the render pass is Blend Modes. Composite all of the render passes for the Space Mechanic using Blend Modes and by adjust the transparency. Once you have finished, upload your project to D2L.

After you have saved the project file on your personal external storage device (like a thumb drive), please upload your After Effects Project File (.aep)to the Space Mechanic dropbox on D2L.

Before you upload your files to D2L, please ensure your files meet the following naming conventions: