2011

whether to contribute to a pass or not (compare the Mono camera against the
Right and Left cameras on Render Layer 1 in our example).
■ A render pass composition imports render pass file sequences; it's a footage
composition.
■ A render layer composition assembles the render passes for a given render
layer. A render layer composition is basically a representation of the 3D
application shading/rendering network that produced the set of passes for
a layer.
■ A scene composition assembles (stacks) the render layers in the scene for
a specific camera view point.
Sets or pairs of cameras are also supported by the pre-compositing workflow
(for stereoscopy purposes).
■ Render passes produced by cameras of a set (Right and Left cameras in our
example) are imported in the same render pass composition in Composite.
■ Dependency graphs of render passes produced by camera pairs are also
created in the same render layer composition.
■ Finally, render layers produced by camera pairs are stacked in the same
scene composition.
This classification facilitates stereoscopic compositing once in Composite. The
dependency graph of the left camera can be manipulated next to the
dependency graph of the right camera in the same composition, allowing
expressions to be set between the two dependency graphs. Or, if you import
in Multi-Stream mode, images from the left and right camera views can be
merged and processed by a multi-stream dependency graph—see
Working
with Stereoscopic Compositions
on page 319.
TIP Pre-comp files are actually Python modules that you can read and edit with
any text editor. Just be sure to conform to the Python syntax if you choose to edit
your pre-comp file. Otherwise, Composite will encounter an error and display a
dialog box highlighting the problem.
About Pre-Compositing | 301