About Anchors			Pre-Comp File Creation and Updates
Chapter 9, Pre-Compositing

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Template Types

Creating a Pre-Compositing Template

A pre-compositing template is a Toxik composition, a .txcomposition file. There are three types of templates: layer, scene, and merged. A template contains an arbitrary number of anchor link nodes that source an arbitrary dependency graph.

The anchor link nodes in a template can be unconnected or linked to existing compositions; the link is simply replaced when the template is used to create a composition.

A template has at least one output (the primary) which is typically the final look of the render layer or scene. However, you can add an arbitrary number of secondary outputs to the template.

Template Types

There are three types of templates that you specify in the Pre-Compositing Import Options dialog box during import: layer, scene, and merge.

The layer template assembles passes from a single layer. This is the default template provided with Toxik. For example, the following shows the default Maya 2009 layer template provided with Toxik. Its link nodes have render pass anchors that match the default name of the standard render passes in Maya 2009.

Because the layer template assembles passes from a single layer, the render layer template composition must contain link nodes with a render pass anchor on them--see Pre-Compositing Anchors. On render layer templates, the render passes are assembled to reflect the shaders network in the 3D application. The render layer template can be different on each layer. If no render layer template is specified, the default layer template for the given 3D application is used.

Note: In Maya, the path to the render layer template composition can be specified on the render layer node.

The name of the default template is based on the application name and its version, such as Maya2009_LayerTemplate.txcomposition. The script uses the template file that is closest to the version that the application used to generate the pre-comp file.

Default pre-compositing templates are located in:

• Windows: C:\Program Files\Autodesk\Autodesk Toxik 2009\resources\precomp\templates

• Linux: /usr/autodesk/Autodesk_Toxik_2009/resources/precomp/templates.

The scene template stacks the layers using Blend & Comp nodes and assembles the layers in the same order as in the 3D scene. This template assembles layers in the scene for a given camera view, so the scene template composition must contain link nodes with a render layer anchor on them--see Pre-Compositing Anchors.The scene template can be different for each camera view. If no scene template is specified, the layers are stacked using Blend & Comp nodes and the layers are assembled in the same order and blend modes as in the 3D scene.

Note: In Maya, the path to the scene template composition can be specified on camera node.

The Merge template assembles all passes of all layers, so the merged template composition must contain link nodes with both Render Pass and Render Layer anchors on them--see Pre-Compositing Anchors.

Creating a Pre-Compositing Template

You can create your own template for pre-compositing.

1. Import a pre-comp file without specifying a template--see Pre-Compositing Import.

   If you are creating a render layer template, the render layer composition contains a number of link nodes to render pass footage compositions. The render pass anchors are already set on the link nodes--see Render Layer Composition Creation.

   If you are creating a scene template, the scene composition contains a number of link nodes to render layer compositions. The render layer anchors are already set on the link nodes--see Scene Composition Creation.

2. Build the dependency graph.

3. If needed, edit the render pass or layer anchors--see Pre-Compositing Anchors.

4. (Option) Clean up the template by selecting Composition > Pre-Compositing and one of the clean-up options. When cleaning up the template, link nodes are reset, their name is changed to match the anchors, and unused anchors are removed from nodes and output sockets.

5. Provide the pre-comp file (.txcomposition) to the 3D artist as the render layer template.