Gradually change the opacity of an image from one side of the screen to the other

[Michael Leibson]

(Many days later) I found that one solution is to create and animate a negative mask over that image, that begins by totally obscuring the image and ends — at the other side of the image — with complete visibility. Applying maximum feathering (both inside and out) contributes to a smooth-looking effect.

[Peter Mcauley]

Hi there!

Glad to see that you figured that out! You can use either a mask or a matte to generate the result that you need, which is adding alpha channel transparency to the source shot. I would recommend trying the BCC PixelChooser to help with that process – essentially, you apply the BCC PixelChooser to the source shot, and in the filters Mask group you can generate animated geometric mask shapes with a soft feathered edge, or you can use some of the built-in animatable vignette tools in the Matte section.

You can find more info on that here :

https://borisfx.com/videos/?tags=feature:PixelChooser,product:Continuum&search=pixelchooser

Cheers,
Peter.