Compositing in 3D Space with Action >

# About Surfaces

You use surfaces to display media in the scene and then composite front and matte clips with a common back clip.

You should have a working understanding of Action media and the relationship between media and surfaces to be successful in using Action.

A surface is used to place a media in the scene. To use media that you load into Action, you must add a surface to the scene for that media. A surface has the following characteristics:

- A surface type can be flat, bilinear, bicubic, or extended bicubic.
- The same media can be applied to multiple surfaces. Any cropping, blurring, or recolouring that you apply to one media is applied to all the surfaces for that media. For example, if you blur a media, all of the surfaces using that media are blurred.

The first time you open Action during a session, an image surface is added to the scene using the first media (if Auto Image is enabled in the Action Setup menu). You must add a surface for each additional media before its clips can be used in the scene. You can then add textures and lighting effects, or change the surface's properties such as its shape, transparency, and specular highlight. Once added, the media appears in the Media list.

By default, a Flat surface is added. You can change the surface type in the Shape box of the Surface menu. See Changing the Shape of a Surface.

You control the position of the surface using axis, rotation, scale, shear, and other attributes related to its placement. See Manipulating an Object's Axis.

#### Topics in this section

- Adding Surfaces
- Modifying Surfaces
- Blending Curves
- Editing Tracker Offsets of a Bilinear Surface
- Warping an Extended Bicubic Surface
- Adding Drop Shadows
- Reordering Surfaces