Compositing in 3D Space with Action >

# About the Perspective Grid

Use the Perspective Grid node to help you with perspective alignments in your Action scene. The perspective grid creates a rectangle on a plane within the perspective of the clip. The accuracy of the plane determines whether any adjustments are properly scaled and oriented in your clip. Objects can be placed anywhere on this plane. Aligning objects to the perspective grid has multiple benefits:

- You can perform a 4-corner pin with a surface or geometry that respects the perspective.
- Aligning the grid establishes the orientation of the plane in 3D space and the Field of View (FOV) of the camera that shot the scene.
- Because the Perspective Grid node has an axis-like behaviour, objects attached to it inherit the grid's 3D transformations.

## Working with FOV

You can animate the perspective grid by positioning corner points in other frames. To create an animated transform, place the grid in the first frame, then Lock Camera in other key frames. You would also enable the Lock Camera if the camera FOV does not change over the clip.

NoteIf you enable Allow Adjustments, Action will solve for the FOV in each frame on which you edit the corners.

To use the existing value in the camera and not solve for it, regardless if you animate the perspective grid, you should lock Camera before positioning in the first frame.

NoteWhen the FOV of the camera is computed (not locked) the camera is repositioned in order to frame the media.

#### Topics in this section

- Aligning an Object with a Perspective Grid
- Perspective Grid Menu Settings