There are several feature requests that which an 3D import for smaller animations. I would be happy when you go some steps further and create a standalone WebGL based 3D engine because there is no professional one on the market (forget the Unity WebGL export). A engine like this with a focus for digital services, marketing web / mobile experience and rapid game dev prototyping could have a huge impact for ProtoPie. And thats the final step them. The ProtoPie integration. Use an engine like described above to handle 3D objects, camera, light, animation(?) and then integrate it in ProtoPie with several communication points. I could imagine something like an 3D environment with a 2D user interface (which is handled in ProtoPie). Already simple 3D behaviours like a camera movement and rotation through the 3D scene when interacting with the UI could be amazing for a lot of products. Maybe physical products which are prototyped with ProtoPie, too. ;)