SubCutscenes allows you to have a cutscene play within another cutscene in a similar fashion to After Effects PreCompositions in case you are familiar with it. This way, you can if you want, organize complex cutscenes into more manageable “blocks”. This is done using the SubCutscene clip found under the “Composition” category of an ActionTrack that has been added in the Director Group.
The length of the clip will always be the same as the actual Cutscene that is referenced which will simply be sampled at it’s local time. One thing you should remember, is that the SubCutscene’s CameraTrack if any, is temporarily disabled for the duration of the SubCutscene clip, since there can practically only be one active Camera Track at a time and thus only the “master” cutscene’s Camera Track will have an effect.