We've added two new tools to the AI image generator!
Canvas
lets you sketch a rough layout before you generate. 
Open a blank frame, pick up the brush and block out the composition - where the actor stands, where the window is, what's on the desk. Then add a prompt and hit Generate. The AI follows your layout, so you can keep iterating on the prompt without losing the composition you have in mind.
Refine
lets you draw over a generated image to highlight where to make a change, without affecting the rest of the frame. 
If the result isn't right, the previous version is saved as a revision so you can hop back to it.
It's particularly handy late in the process, when a brief change comes in and you don't want to rebuild the whole AI-generated frame from scratch.
Both tools are in the Canvas tab in the Editor. Open any frame, head to
Generate
→ Canvas
to give them a try.