3D: What Is It?

In surveying, it is called a station point. Usually, it is an iron bar painted with even divisions on it and planted into the ground, just like Armstrong’s flag. It is then sighted with surveying instruments, and all distances are calculated from it. That is exactly what a world origin is for. It is also the first thing the software needs to know before it can do anything. In your case, you don’t have to know this fact to start making objects in 3D any more than you have to understand linear perspective either. In both cases, the software has this information built in and it does the work for you. However, not knowing this information can cause a great deal of frustration later, because it affects how tools behave. These concepts are how your application sees the world, and you have to understand that if you are to smoothly interact with a 3D application.