Understanding the Perspective Corner Pinning option

When you track using the Perspective Corner Pinning option, you simultaneously track four points in the source footage. When applied to the target footage, the Corner Pin Effect uses the movement of the four points to distort the layer, simulating changes in perspective.

For example, if you are replacing a sign on the side of a moving bus, the edges of the sign may be partially obscured because of shadows or objects; but a window on the bus may be visible throughout the footage. You can first define four feature regions that are distinct and easy to track, and then move the attach points to the four corners of the sign. When the new image appears in the sign, After Effects calculates the relative movement between the feature regions to create the correct perspective.


When you choose perspective corner pinning, the default positions of the attach points form a rectangle in the center of the motion footage layer (left). Moving each feature region extends the rectangle in the direction of motion (center). You can place the attach points anywhere in the motion footage layer (right).