I have a shape that I made in Illustrator that I want to import into AE and use as a mask to hide several objects on several different layers. I want everything around the shape to be masked and everything within the shape to be visible. How can I achieve this?????
Probably the easiest way would be to import your illustrator shape, pre-compose it and the layers you want to mask (the shape should be the top layer), and set the shape's blending mode to Stencil Alpha.