this is tips for create image seq with alpha and assign to materia without flipbook.I used ue 4.10.1.
ok first of all we need png sequence with alpha channel.
for this when u finished ur footage in after effects , export it as png sequence (RGB+Alpha).
now we can start tips.
1)Import ur png seq to after and create new composition.
2)now create first render queue from sequence and set loosless option like below.
2)then create second render queue from sequence and set loosless option like below.
3)ok after renders are finished.we’re going to ue4 and import both of (mov) files.
in content browser select both files at the same time.right click and hit (Play movie) and again with both selected , right click and hit (Create Media Texture).
4)create new material.assign rgb sequence to emissive color and alpha sequence to opacity.
set blend mode to (Translucent) and shading model to (Unlit).check two sided.like below.
5)create cube and assign material to it.then we have sth like below.
6)U can change material domain to (User Interface ) to use ur alpha image sequence as UMG.