Using Transitions
What is a transition?
A transition is the video effect used to progress from one clip to another in an editlist. At its simplest, a transition is a dissolve, which means that one clip dissolves or fades into the next.

Transitions on the Virtual Edit timeline are represented by purple bars between overlapping clips. Transitions maybe altered by dragging a preset transition from the 'clip browser' window onto a transition overlap on the graphical edit timeline, as shown below:

Each transition bar has a tiny picture showing what the current transition looks like. Which for dissolve looks like: and for an arrow looks like: . The little 'R' on the transition states that the transition has been pre-rendered.

Transitions may also be altered by double clicking on the transition overlap to show the 'Transition FX' properties dialog box, which will allow more experienced users to specify their own effects based on the effect parameters.

The 'Reverse TFX' option runs the transition in reverse, i.e. a circle effect would go from the edge to the middle as opposed to from the middle to the edge. The 'Must Pre-Render' option forces the transition to be Pre-Rendered regardless of the options specified below. The 'Cross Fade Audio' option cross fades the audio during the transition, the default option is set to on.

Why Pre-Render?
Depending on the processing power of your PC, transitions may or may not be rendered in real time, while playing an editlist. This is because transitions can be mathematically intensive processes. Therefore, if an editlist is jerky during playback, there is the option of 'pre-rendering' the transitions. This means that transitions are calculated in advance and saved as temporary files.

There are various options for specifying the pre-render mode of Virtual Edit under 'Options->System Options', as shown below:

  • Level 0 specifies that no pre-rendering is done. This is suitable for people with high powered PCs, or when you wish to disable pre-rendering because it is disrupting creative flow when making changes on the timeline.

  • Level 1 specifies that only complex pre-rending is done. This applies to all transitions apart from dissolves. This mode is particularly useful for assembling an editlist with basic (dissolve) transitions. Then, when you are happy with the overall editlist, the basic dissolves maybe replaced by more complex transitions. i.e. these more complex transitions will need to be pre-rendered which can be disruptive to the creative flow.

  • Level 2 specifies that all transitions are pre-rendered. This is suitable for people with very slow PCs, and dont wish to have jerky playback of editlists.

Another useful feature is the ability to delete stale, or unused pre-render temporary files, to save disk space. But this has the disadvantage that if you 'undo' an edit on the timeline the previous pre-rendered files would have to be recreated.