Sometimes you need more 3D content than what Photoshop will give you. There are some great 3D resources that you can access right from within Photoshop. Just go under the 3D menu to the bottom and choose Browse 3D Content Online. This will open you browser to an Adobe landing page for 3D. Here you can download free materials, access stock 3D libraries like 3dvia and Archive 3D. There are also links to other news and training for 3D in Photoshop.