The volume of space viewed by the camera eye is called the frustum. The frustum is in effect a viewing pyramid. The camera eye is located at the apex of the pyramid, and the far clipping plane forms the base. The pyramid may be truncated by the near clipping plane.

If you place a surface within the frustum, it is visible in the final animation. If the surface is located outside the scope of the frustum, it is not visible at that frame in the animation.

To see the camera and frustum:

1. From the View box, select Side.

   
   

2. In the image window controls, click to zoom out from the scene.
3. Select Pan in the Edit Mode box and pan around the scene until you see the camera eye icon. Alternatively, use Orbit mode to pan around the scene in circular motion.
4. Go to the Camera menu and drag the Roll field until you see the four sides of the frustum.
5. To modify the frustum, do one of the following:
   • Change the position of the near clipping planes to alter the depth of the frustum. See Moving the Clipping Planes.
   • Change the position of either the camera eye or the camera's point of interest to alter the orientation of the frustum. See Moving the Camera Eye and Point of Interest.
   • If the Physical Camera button is disabled, enter a value in the FOV (field of view) field to adjust the width of the camera frustum.
   • If the Physical Cam button is enabled, enter a value in the Focal Length field to narrow or widen the frustum. You can also alter the depth of the frustum using only the near clipping plane.