Once you have imported the 3D model into your scene, you can easily manipulate it to set up your scene. You can even add keyframes, just like any other element, and animate it on a trajectory.
Using Peg Nodes to Control the Position of 3D Objects
You can use Peg nodes to control the position of 3D objects, and connect them as you would with 2D layers to create rigs.
Using Transformation Tools to Manipulate 3D Models
Once the 3D option is enabled, your transformation tools automatically become 3D transformation tools. This means you can now manipulate them on the Z-axis as well. The Translate , Rotate and Scale tools are found in the Advanced Animation toolbar and the Transform tool can be found in the Tools toolbar. You can use these tools to set up or animate your 3D model.
You can also set up all these position parameters using the Layer Properties window—see About 3D Parameters.
NOTE Just like with 2D layers, if you're setting up the initial position of your 3D models, you should set the Animate mode to Animate Off in the Tools toolbar, then set it back to Animate Current Frame when you're ready to animate.