So after creating our models by importing and tracing pre-existing images, I found this video that reminded me very much of that process. In this commercial by MSN Canada, you can see 3D models of real-life objects attached to the butterfly wings. It would make sense that these models would be easily made by tracing existing images as well. I also love how this video uses liquid and smoke effects (with the cocoon and flu shot butterfly, respectively). Check out the commercial below, it's really well done!