Applying Operators

An operator is an operation that modifies a layer or a composite. It can be as simple as a Box Blur filter, or as complex as a Paint animation. Operators are processed one after another. The result of one operator serves as the input for the next.

You can apply an operator to a single layer, to a composite or a nested composite, or to an entire branch. You can place an operator anywhere in the branch—on a layer, on a composite, on the output of a nested composite, or on the output of the entire branch. At any point in your project, you can move an operator to another place in the process tree, modify its properties, change its animation, copy it, or simply delete it.

In the following three illustrations, note the operators on each layer, especially the Box Blur, which is applied at different points in each example.

In the first example, the Sky layer is modified by a single Sharpen filter. The Couple layer is modified by three filters, each one affecting the result of the filter below it: the Linear Keyer is applied to the footage, then the Matte Controls operator is used to refine the output of the Linear Keyer. The Brightness/Contrast filter is used to brighten the keyed result. The Couple layer is composited with the Sky layer and the Box Blur is applied to the output of this composite.

The second example is the same except that the Box Blur is moved onto the Couple layer.

In the third example, the Box Blur is moved onto the sky.

Operators can be grouped into four main categories, each represented by a different icon in the Workspace panel:

• Filters, which include noise filters, keyers, color correctors, particles, third-party plugins, and so on. These operators are described in Filters.
• Paint operators, which include Paint, Text, masks, and selections. For more information on Paint operators, see Introduction to Paint.
• Composite operators, which composite the layers in the workspace. combustion automatically adds a Composite operator when you import or nest layers.
• Footage operators, which determine how the source footage is interpreted in the composite. For more information on the Footage operator, see Changing Footage Source Settings.