@mark_m said:
but how do you do this?
! Quick Answer: Use the Background Color actor to create a 'canvas' that will fit all your stages in one.
Here is an example file create in Isadora 3.2.6
It requires for 1920 by 1080 video files as sources. (you can swap in any 4 sources of the same size).
NOTE: I use a Shapes actor to generate some 'sprite' and animation in this example, but if you wanted to animate an Image or Video (picture player or movie player) across the large canvas, I would replace the MultiMix (and shapes) with the Player (movie or picture) and another Matte++, again with 'scale FG' set to off. In that state it works amazingly as a compositor/animator of 'sprites'.