How does 3d vision work with one eye compared to two eyes?

Depends on both eyes. 3d vision depends on both eyes. The brain takes the inputs from both eyes and uses the different perspectives to create the 3d image with depth perception. If you go to a 3d movie you can get an idea of how this works. If you take your glasses off you can see that there are two images projected onto the screen that combine to create the illusion of depth.
Depth perception. 3d vision requires both eyes ti work together. Each eye looking at an object at a slightly different angle creates depth perception. 3d vision is not possible with only one properly working eye, but we can gauge distances (depth perception) to some degree by the position of shadows relative to objects. So, a one-eyed person can drive well, but cannot watch a 3-d movie.
Not the same. True 3d vision (medically called stereopsis) requires good vision in both eyes. Both eyes have to be working at the same time. One lazy (amblyopic) eye will prevent true stereopsis. ~1 out of every 20 people lacks true stereopsis for any of a variety of reasons. One-eyed people usually develop compensating mechanisms that let them function just about as well as folks with true stereopsis.