download the keynote file: download moonslidedeck
script: I recently got a question about how to phase a moon using keynote animations on the showroom background. If you were to do it on a white background you could simply drop a white circle on top of your moon and dissolve it in.
This gets a bit more complicated when you try to attempt the same effect on a complex background like the beautiful showroom background included in Keynote. You can't simply drop a white circle on the moon because it looks awful. So how do you accomplish this.
You can accomplish it using instant alpha. First copy the part of the moon you want to phase out, and paste it on another slide. Then using the square shape, create a high contrast background. From there export the slide in .png format.
Open your newly exported picture and instant alpha the moon cut out. I like to use preview, but you could also do this within keynote. Once done, save your image. In keynote, create a new slide, drag your image in, make sure it is centered, and then export the slide to .png again. Then take your newly exported image and drag it back in over the moon. Instant Alpha the background, apply the dissolve build, and you are done!
