User Manual

Transforming Upstream, Lighting Downstream
When building complex scenes using multiple Merge3D nodes being combined together, it’s
common to use one last downstream node to combine light and camera nodes to illuminate the
final scene, while leaving the upstream Merge3D nodes free for controlling object transforms
and animation. This way, you can transform and animate subsets of your overall scene without
worrying about accidentally altering the overall lighting scheme or cameras for that scene,
unless you’ve specifically connected lights or cameras upstream that are meant to be attached
to the geometry you’re transforming.
An example of a 3D scene using multiple Merge3D nodes working together; the upstream
Merge3D nodes arrange the 3D objects placed within the scene, while the last Merge3D node
(orange) lights and frames the scene.
The Renderer3D Node
Every 3D node you add outputs a complete 3D scene. This is unlike most traditional 3D
modeling and animation programs, where all objects reside within a global scene environment.
This means that the scenes created by a Camera 3D node and an image plane are separate
until they’re combined into the same scene via a Merge3D node, which itself outputs a
complete 3D scene. However, this 3D scene data can neither be composited with other 2D
images in your composition nor rendered out without first being rendered within the node tree
using a Renderer3D node.
To be more specific, 3D nodes that output 3D scenes cannot be connected directly to inputs
that require 2D images. For example, the output of an ImagePlane3D node cannot be
connected directly to the input of a Blur node, nor can the output of a Merge3D node be
directly connected to a regular Merge node. First, a Renderer3D node must be placed at the
end of your 3D scene to render it into 2D images, which may then be composited and adjusted
like any other 2D image in your composition.
Output of a Merge3D connected to a Renderer3D node to output 2D image data.
Chapter – 76 3D Compositing Basics 1542