After Effects is slowly shifting from a 2.5D environment( Flat surfaces distributed in 3D space)  to a platform which supports importing 3D models.

After Effects gives you the option to extrude shape layers and text layers.

 

Currently – these are 2 options for  full 3D models in AE:

Built in 3D integration between After Effects and Cinema 4D:

This Means that you also have to own Cinema 4D ( Students get free license) but all of the animation is done in Cinema 4D.

https://www.youtube.com/watch?v=YJ0Z7iI7oXA

https://helpx.adobe.com/after-effects/how-to/insert-objects-after-effects.html

External Plugin – Element 3d (Paid – $199):

With Element 3D – ALL of the animation is done within After Effects:

https://www.videocopilot.net/products/element2/