Creating a Transition Widgets

A transition widget is created like any other After Effects project, but the way it’s used in our engine requires some extra carefullness and involves some extra work.

Transition Widgets have 2 mendatory graphical placeholders:

  • One for the input video (tagged IMAGE_01)
  • One for the output video (tagged IMAGE_02)

Transitions are always inserted between two Widgets elements, and when our render engine stumble upon one, this is what he does:

  • It renders the Widget before the transition
  • It renders the Widget after the transition
  • It then fill the transition with the rendered Widgets videos

What does this means , it first means that your placeholder will get a rendered version of the in and out Widgets, so transition can’t change anything in them. it also means that in order to be seamless, the In placeholder must start fullscreen, and the Out placeholder must finish fullscreen.

It’s not easy to explain the behavior with words (and then, not easy to have a clear mind about it when reading this), but if you try this transition project, you’ll see in context what it does. You can download it here.

All the magic is happening in the transition precomps, which are the transition widgets.