You can render your final scene with images in the background or with just the CG elements so that you can later composite them with the live footage. Compositing is the recommended approach, but both methods are supported.
In order to render the image plane, you must turn off the Use Cache option on the Setup control panel. The Use Cache option utilizes a Roto node, which does not render. By turning Use Cache off, Live switches to the standard Maya image plane, which is renderable.
To render just CG elements, you can leave the Use Cache option on or, if you turn it off, set the Display Type to None in the image plane attributes.
If you have live action footage matted against a CG background, the background geometry may become clipped off. This problem occurs because Live places the far clipping plane immediately behind the image plane. To correct it, open the camera attributes and edit or delete the expression for the far clipping plane.
