Hi, I'm just starting to learn how to use After Effects. I'm trying to apply a mask to a layer. I figured out that right clicking on the layer and going to Mask > New Mask adds a mask. My problem however is that the the layer I want the mask to mask moves but I want the mask to stay still. How do I go about doing this? Thanks in advance for any help.
Masks are on layers. Perhaps what you're looking for is a track matte. A track matte is a layer that defines transparency for an underlying layer. If you move the underlying layer, the track matte layer doesn't move with it (unless you explicitly connect them with parenting or something like that).