The Transition section
The Transition section is where you fine-tune one transition: its style, how it’s eased and how long it lasts.
- Where
- Clip tab ▸ Clip sub-tab ▸ Transition
- Agent tools
set_transitionset_transition_styleset_transition_duration
Open the section
Section titled “Open the section”Select the later clip of an overlapping pair, then look on the Clip sub-tab of the Clip tab. A transition belongs to the clip it leads into, so the earlier clip of the pair won’t show it unless it overlaps a clip before it too.
The section appears only when exactly one clip is selected and that clip overlaps the clip before it. To change several transitions at once, use Clip ▸ Transition ▸.
It starts closed. Its header sums it up, for example “cross dissolve · ease in out · 0.50 s”, or “none” when the overlap has no stored transition.
| Row | What it does | Values |
|---|---|---|
| Kind | The style, or none | None and the thirteen styles |
| Curve | How the transition’s progress is eased | Linear, Ease In, Ease Out, Ease In Out |
| Crossfade Audio | Whether the sound crossfades. See Crossfades. | On or off |
| Crossfade Shape | The crossfade’s curve. See Crossfades. | Linear, S-Curve, +3 dB, −3 dB |
| Duration | The length of the overlap | 0.02 to 10 s |
Each change is one undo step.
Kind lists None, then the thirteen styles in the same order as the Clip ▸ Transition ▸ menu. Changing the style keeps the Curve and the crossfade settings.
Choosing None removes the transition but not the overlap. See None keeps the overlap.
Curve changes how the transition moves through its length, not how long it lasts.
| Curve | How it moves |
|---|---|
| Linear | At a steady rate from start to finish |
| Ease In | Starts slowly and speeds up |
| Ease Out | Starts quickly and slows down |
| Ease In Out | Starts and ends slowly |
The sound crossfade follows the same curve.
The curve also moves the swap in a Fade Through Black or White. With Linear or Ease In Out the clips swap halfway through the overlap. With Ease In it’s about 71% of the way through, and with Ease Out about 29%.
Duration
Section titled “Duration”Duration is the length of the overlap, in seconds. Type a value, or pick 0.25, 0.5, 1 or 2 from the arrow at the end of the field. A number outside 0.02 to 10 s is pulled to the nearer end of that range, and the result snaps to the frame grid. A value that rounds to no frames at all closes the overlap and leaves a hard cut.
The overlap is the transition’s length, so changing Duration moves the later clip to match: earlier for a longer transition, later for a shorter one. Only that clip moves.
- Clips after it stay where they are, so a longer transition can open a gap after the clip.
- A shorter transition can run the clip into the one after it, and that new overlap gets a Cross Dissolve.
- A linked clip doesn’t move with it.
Frame Job won’t let an overlap pass half the shorter clip, or move the clip anywhere that breaks the overlap rules with its other neighbours. The message at the foot of the inspector names the limit, and nothing changes.
Alignment
Section titled “Alignment”Alignment decides which clip’s footage a new overlap at a hard cut is made from. The section has no control for it. Clip ▸ Transition ▸ always centres a new overlap on the cut: half of it comes from each clip, an odd frame comes from the incoming clip, and a side that runs short passes its share to the other.
An agent can choose the side with the align argument of add_transition:
| Choice | Where the footage comes from | What stays put |
|---|---|---|
center, the default |
Half from each clip | The moment of the cut |
before |
All from the start of the incoming clip | The outgoing clip’s last frame |
after |
All from the end of the outgoing clip | The incoming clip’s first frame |
Default values
Section titled “Default values”A transition Frame Job makes starts with Curve at Ease In Out and Crossfade Audio on, with Crossfade Shape at +3 dB. When you didn’t choose a style, it’s a Cross Dissolve.
An overlap with no stored transition, such as one you set to None, draws as a linear Cross Dissolve with no crossfade. The section says so: Kind reads None, Curve reads Linear and Crossfade Audio is off. From there:
- Changing Curve or Crossfade Audio stores a Cross Dissolve with exactly the values showing, and your one change. Crossfade Shape stays dimmed until Crossfade Audio is on.
- Choosing a Kind makes a new transition with the defaults above, not the values that were showing.
Good to know
Section titled “Good to know”Two overlapping clips with no picture get the same section. Only their sound changes, so Kind has no visible effect.
With an agent
Section titled “With an agent”set_transition_style sets Curve, Crossfade Audio and Crossfade Shape through curve, audio and audio_shape. Anything left out stays as it is, and leaving out all three is an error. Unlike the section, it works on any clip but an adjustment clip. A clip with no transition gets a Cross Dissolve with that style.
set_transition_duration does what Duration does, and it fails on the first clip of a track, which has nothing to overlap. A length that rounds to no frames is an error there, where Duration closes the overlap. set_transition sets Kind.
See set_transition_style, set_transition_duration and set_transition.