Which tool is primarily used for animating 3D layers in After Effects?

The Transform Tool is pivotal for animating 3D layers in After Effects because it encompasses the key properties necessary for manipulating layers in a three-dimensional space. This tool allows users to adjust position, scale, rotation, and opacity, which are essential for creating dynamic animations. When working with 3D layers, transforming these attributes effectively gives the illusion of depth and movement in the three-dimensional environment.

For example, by adjusting the rotation of a layer on the X, Y, or Z axis, you create realistic movements that can simulate a 3D object turning or spinning, making layered compositions visually engaging. Additionally, the Transform Tool integrates smoothly with keyframes, enabling users to animate these changes over time, further enhancing the complexity and fluidity of the animation.

While the Camera Tool is also important in 3D environments because it allows for interaction with and navigation through 3D space, it does not directly perform the transformations on layers themselves. The 3D Orbit Tool is specifically designed for changing the viewpoint around 3D layers rather than animating them. The Animation Pane, while useful for managing and previewing animations, does not function as a tool for directly modifying or animating 3D layers. Hence, the Transform Tool is the