To add a surface:
In the Media list, select the media containing the back or front/matte that you want to add to the scene.
Do one of the following:
The surface is added to the scene with its own axis. The selected media in the Media list is automatically applied to the surface.
Notice that when front/matte media is applied to the image surface, the front and matte clip are combined. You can turn off the matte in the Matte Clip box in the Media menu to show the entire front clip.
If you later decide to change the media on the surface, select the surface in the schematic, then select the new media in the Media list and click Apply.