Accessing the Compositor

The Compositor is accessed from the Effects menu. To access the Compositor, you must select a front clip, a back clip, and a matte clip.

To access the Compositor:

In the Main menu, click Effects.
In the Effects menu, click Compositor.
Select the front, back, and matte clips.

Select the destination.

The Compositor controls are described as follows.

Crop boxTurns cropping on or off, or allows for an automatic crop. See Cropping the Front Clip.

Front clip boxEdits the front clip's visibility.

Select:	To:
Front On	Display the front clip.
Front Off	Hide the front clip.
Front Lock	Lock the front clip at the current frame in the timebar.

Back clip boxEdits the back clip's visibility.

Select:	To:
Back On	Display the back clip.
Back Off	Hide the back clip.
Back Lock	Lock the back clip at the current frame in the timebar.

Matte clip boxEdits the matte clip's visibility.

Select:	To:
Matte On	Display the matte clip.
Matte Off	Hide the matte clip.
Matte Invert	Invert a matte. Black areas will be made white, and white areas willbecome black.

Colour Corrector controlsAllows you to colour correct the front, back, or matte clip. See Colour Correcting Clips.

Stabilizer controlsAccesses the stabilizer, and applies translation, rotation, and scaling settings to the composition. See Tracking Clips.

Motion Path settingsSets motion paths for the front clip and camera. See Creating Motion Paths.

Shadow buttonPlaces a shadow behind the front clip. See Adding a Shadow to the Front Clip.

Texture buttonEnables hardware texture mapping.

Anti-Aliasing and Softness fieldsControls the level of anti-aliasing. Increasing the number of samples increases the degree of anti-aliasing but also increases the processing time. Adjust the softness to affect the degree of anti-aliasing.

The jagged lines that often occur along the edges of diagonal or curved lines when processing high-frequency images such as text are the result of aliasing. Aliasing is caused by insufficient spatial sampling of the image. The process of reducing or removing the effects of aliasing by increasing the sampling rate is called anti-aliasing.

NoteAlthough the cleanest images are obtained when the softness value is set to 1 or 2, higher softness values can also be used for creative effects. The best results are obtained when the softness value is set as indicated in the following table.

Anti-aliasing	Softness
1	No anti-aliasing occurs and the Softness value has no effect on the image
2	1
3	2
4	2

Resolution fieldSets the resolution of image proxies while you work with a layer and play clips in the Compositor. A lower value requires more processing time to generate proxies.

NoteWhen hardware texture mapping is enabled (Texture button), the value in the Resolution field no longer applies because the hardware controls resolution during interaction and playback.

Motion Update buttonUpdates properties such as position, rotation, and colour in the scene. This button is enabled by default.

When disabled, animated objects do not move, but keep the position of their current value. Disable Motion Update when you want to copy keyframe values from one frame to another.

Play Lock buttonUpdates the animation settings according to the frame or timebar position as you move through the clip while keeping it locked at the current frame.

Channel Snap button and Snap fieldSnap keyframe values in the animation curve window. When you move a keyframe in this window, it is automatically aligned to the snap grid.

The grid size is set to one unit along the X (horizontal) and Y (vertical) axes. To change the grid size along the Y-axis, change the value in the Y Snap field. You cannot change the grid size along the X-axis.

Blending boxDefines the blending mode. The Blend option uses both the front and back luminance curves of the matte clip. The Add option uses only the front luminance curve. Select Add to eliminate the black fringe created when using a front clip with a black background.