Managing Your Work Environment > Setting Preferences > Timeline Preferences >

# Containers

Use the following preferences when working with containers on the timeline.

Lock Container Effects button
  Use to control how effects associated with segments are processed when you create containers.

- Enable to prevent recalculation of multi-layer effects when you move their container. This is useful when containing a composite in which a background is outside the container.
  NoteWhen a soft effect is processed, it is locked. If the effect is part of a layered effect and the bottom part is moved, the effect is invalidated, and the result may differ once the effect is unlocked. Also, a locked effect does not display the soft effect quick menu when selected. To unlock the effect, you must either enter the editor, unlock it, or add an additional effect.
- Disable to reprocess any effects that have been invalidated or not yet rendered.

Uncontain Options box
  Use to determine whether new layers and tracks are overwritten when a container segment is uncontained. See Working with Containers.

Select: | To:
--- | ---
Uncontain & Overwrite | Overwrite segments outside the container on layers and tracks that conflict with the container segments.
Uncontain & Add Tracks | Preserve tracks when you uncontain a container by adding sufficient new layers and tracks to house the previously contained segments. All tracks inside and outside the container are preserved.

Contain Timewarped Edits button
  When you perform a fit-to-fill four-point edit, you can enable Contain Timewarped Edits to preserve the edits (including splices and/or transitions) in the incoming clip by containing the incoming clip and applying a timewarp to the container instead of the clip. The result element is a timewarped container, and the container contains the edited incoming clip—all its splices and/or transitions preserved.