Faced with steep learning curves and limited personnel, we looked for alternatives to creating all of our 3D environments and objects from scratch. We had two game industry professionals who donated time to create early prototypes of a girl character, and who provided tips and guidance. But soon we found other sources of 3D assets. 

Established online stores such as Turbosquid and The 3D Studio offer a vast array of models, some of them free. The trick to using those assets is making sure you acquire them in file formats that your working software can handle. The best format for Unity is FBX, but it is also simple to import OBJ, .ma (Maya) and .max (3DS Max).

Unity Technologies introduced their own Asset Store early in our project, and it has expanded to include a wide variety of models, most of them free or inexpensive, as well as add-ons to Unity that make the mechanics and scripting easier. With the Unity Asset Store, you are assured that all models are compatible.

Other sources are attractive but more difficult to use. The Google 3D Warehouse has many models available for download, but the Collada format is more difficult to use with Unity. Sketchup Pro lets you convert Collada to FBX, as does a limited time evaluation copy of the program. In our project, the Emily Dickinson house, modeled by Beryl Reid, was found in the Literary Landmarks collection, a valuable resource for homes and places associated with authors.

One of the most difficult aspects of using a game engine is the modeling, rigging and animation of characters. Some digital asset stores carry rigged and animated characters, but Mixamo has pioneered a streamlined, online method of designing a character, rigging it, and assigning animations to it. Some characters and animations are free, others are inexpensive enough to make it worthwhile to avoid doing it yourself. It is also possible to design your own character and then have Mixamo rig it through its website, and supply the animations.

A recent development with great potential is the rise of 3D scanners and other ways to record real world objects and convert them to meshes for use in modeling programs and games. Autodesk, makers of Maya and AutoCad, entered the low-end and hobbyist market with the free 123D series of programs. 123D Catch allows a creator to take multiple photos of an object, upload them to the "cloud" and have Autodesk's servers return a 3D mesh. Other programs in the series provide 3D modeling and a connection laser cutters and 3D printer services.