One of the things I’ve wanted for years in Flash was alpha masks. That is, masks that have gradations in transparency, not just boolean visible / not visible as with masks in Flash 7. Now with Flash 8 we finally have them… sort of.
Flash 8 doesn’t have actual alpha masks per se, but it does have a blend mode called “alpha” which emulates them. You can place a clip with a blend mode of “alpha” into another clip with a blend mode of “layer”, and the parent clip will use the alpha of the child clip for compositing. This gives you the visual effect of a alpha mask (even if it really isn’t one). It also has a blendmode called “erase” that is basically the opposite of alpha – more opaque areas on the child clip are less opaque on the parent (ie. the child “erases” the parent).
I spent a few minutes whipping up a super simple demo. It takes a few pictures (my own strange creations), and cross fades them using an alpha blend mode. I tossed together 4 crossfades:
- A shape tweened radial gradient
- A shape tweened linear gradient
- A grid of square clips that fade in randomly
- A grid of square clips that fade in randomly from right to left
Flash Player 8 required. Might take a few seconds to load (85kb).
EDIT: Added a fourth crossfade.