I've looked around, and found a way to create a gradient transparency on an object. I create the shape, then add an opacity mask, draw a box around the shape, set a black to white gradient and make sure the stops are RGB rather than grayscale.That works great if the object below is on the same layer. But what if I want to animate the top object in After Effects and maintain the transparency as it passes over the bottom layer?
No matter what I do, the transparency goes to white, rather than revealing the layer below. Any thoughts on this would be appreciated.
On the first screenshot, you can see the artboard. It has a moon-like shape, which has a transparency mask assigned (top to bottom b&w gradient). This shape is on the top layer, which overlaps a red rectangle, which is on the bottom layer.
On this next screenshot, you can see the layers palette's layout. Simple.
When you save the AI document, check the checkbox in the File Save dialog which says "Create PDF Compatible file". But you probably knew that already.
Then you can import the AI file into AE as "Composition - Cropped Layers" (or don't crop the layers, whichever way you want it).
Then you'll see that you will get a composition and 2 AI layers in AE. Your top layer is the moon-shaped-like layer (in my case), and the bottom layer is the red rectangle layer. The moon shaped object keeps it's transparency mask and can be animated in AE just fine.
Here's the screenshot from AE CS3. You can see the imported 2 AI layers, and on the stage you can see the moon-like shape selected (keeping its transparency), which is hovering over the bottom red layer. Just as it was in AI.
Thanks! I tried again in a new document and it was fine. I don't know what I did wrong on that first attempt. Maybe because I opened an image in Illustrator, rather than opening a new Illustrator doc and placing the image? In any case, all good now. Much obliged.