I'm using Blender for editing desktop recordings that I make using Open Broadcaster software.
I would like to highlight areas of the screen to draw attention to them by surrounding them with a red rectangular box.
I've created a previous post that asks: How to highlight areas of a desktop recording in video sequence editor
The answer to that post is fantastic, and I would like to now understand how to create an image in the UV editor for using as the mask. How can I do this?
I'm a complete Blender noob and have not used any part of Blender except for the VSE.