Exporting an alpha channel and video separately
Just as with image sequences, some VFX applications can make use of the video and its alpha channel as separate files. Motion gives you the option to do just that in the Render menu under Export settings.
Getting ready
Locate a Motion project you've worked with in one of the previous exercises. Double-click to open it. Go through the project and make sure the play range is at the beginning and end of your Timeline. If it's not, click on Option + X to reset the play range.
How to do it...
From the Share menu, choose Export Movie.
Under the Options tab, customize your settings as you see fit. Click on the Render tab.
In the Render tab next to Color, choose Alpha as shown in the following screenshot. This will export out the alpha channel separately. You can also choose whether the alpha is pre-multiplied or not by clicking on the checkbox underneath.
Click the Next button and find a place you want to save it to your system. Choose Save. The file renders...
