Draw over capability

[adamearle]

I was looking for a draw over capability for DJV.

This would include being able to over what is stored in playback and
Be able to have those notes separately of with the play backed asset as a separate file.

Tech that might be able to be used for this is:

1. Blender Grease Pencil animation drawing tool set.
2. Natron Roto Tool animation drawing tool set.
3. Krita draw drawing animation tool set.
4. OpenToonz animation drawing tool set.