These are "image layers" -- go to your Stage tab and you'll see a "new" one you can drag and drop onto the scene.
Then in the Modify tab you go to the material and in the "opacity" slot is where you want to put your keyhole, generated in a program like Photoshop or some such. Black will be transparent, white opaque, so just create a white blank with a black keyhole.
Sigh -- however, I am trying this in 7.3 and I cannot get it to work the way it used to. Maybe I just haven't used this in so long (I do my compositing in an external video editor) that I don't remember how it works. Someone else may jump in here.
Edit: Okay, it seems to work with JPG only (I was using PNG). Why is that? Anyway, do what I suggest above and you'll be fine.
Alienware Aurora R12, Win 10, i9-119000KF, 3.5GHz CPU, 128GB RAM, RTX 3090 (24GB), Samsung 960 Pro 4TB M-2 SSD, TB+ Disk space
Mike "ex-genius" Kelley
Edited
6 Years Ago by
Kelleytoons