The Maya Journal: An Introduction to the User Interface
Challenges to Learning 3D PerspectiveLearning to work in a virtual 3D environment for the first time is a strange experience. I think it's because 3D is both so similar to, but different from, reality. When I see a three-dimensional object like a sphere rendered within Maya's viewport, I always feel as if I'm looking at something familiar, yet also foreign. The sphere is familiar because it looks real enough to touch, however, its strangeness comes from knowing that I can't. I think this is a type of cognitive dissonance that one has to overcome in order to work effectively in 3D. Part of overcoming this requires us to attend to something we seldom think about: the difference between the movement of an object and the movement of our perspective. I'll illustrate this with a real world example: Every day my coffee cup sits at my desk next to my mouse. If I want to see the side of my cup that is presented to me, all I need to do is simply look at it. However, if I want to see the opposite side of my coffee cup, I must execute one of two actions: 1) Either reach out, grasp the cup with my hand, and rotate it around or 2) Get up out of my chair and move to the opposite side of my desk. Simply put, I can either move the cup or move myself. If I choose the first option and simply turn my coffee cup around with my hand, I've chosen to change the cup's relationship to myself. But, if I get up and move to the opposite side of my desk, I've chosen instead to change my relationship to the cup. Although these two distinctions are obvious in the real world, they become harder to differentiate in a virtual 3D environment. This confusion in 3D arrises mostly from a lack of physical references to the physical world and to our own physical bodies. These are two things we often enjoy in everyday situations. When I move my coffee cup, I have objects that orient me to it, like the desk it sits on, the office space, and my own hand reaching out. The same goes for option #2. However, in a virtual world these references can be absent or few in number. When I move a 3D object in virtual space, I again have two options: 1) I can rotate an object using the software's move tools or 2) I can change my (i.e. camera's) perspective of the object by orbiting around it. However, both of these movements can appear as if I'm doing the same thing. That is, orbiting around a 3D object can look exactly like moving the actual object itself. However, this is just an illusion, a type of spatial confusion you have to get used to in order to work effectively in 3D. [caption id="attachment_32902" align="alignnone" width="800"] Photo by Anupam_ts[/caption] A similar type of illusion was responsible for our ancestors believing in a geocentric world where the Sun revolved around the Earth and not the other way around. They, like us, couldn't feel the Earth rotating, so it was a safe to assume that it wasn't. For beginners in 3D, a similar experience happens because of the lack of physical references (i.e. a desk, an office, our bodies). Within the empty spaces of 3D environments, learning to move objects and then move your perspective can be a bit like rubbing your head while patting your stomach.
Going off the GridLuckily, 3D programs provide a great feature to serve as a reference point for any movement of an object vs. movement of the camera. This reference is the gridded plane (or "grid") located in the center of your viewport. The grid is always tied to your camera movement. When you orbit, it turns with your camera's perspective. In contrast, when you turn just the object, the grid remains stationary. Even though the grid can be turned off, it's helpful to keep it on because it helps you understand how your perspective is changing. To illustrate how the grid helps orient you in 3D space, I've provided a video of me turning the grid on and off while orbiting around an object. It also shows me rotating the object versus orbiting around it. It should become clear how these two perspective changes can be confused with one another.
Changing the Camera's PerspectiveMoving around in Maya's 3D viewport takes the mouse and the Alt key. Each mouse button used in conjunction with the Alt key will alternate your perspective in three distinct ways.
- Alt+LMB. This combination will obit your perspective around an object and/or the grid. Clicking and dragging anywhere outside of an object or on the grid itself allows you to orbit from side to side, top to bottom, and anything in between.
- Alt+MMB. This lets you move the camera only along the X and Y axis as if it were 2D. This is helpful when you need to center your objects within the viewport.
- Alt+RMB. Moving your mouse from side to side also moves your perspective closer or farther away from an object. It's good for getting a wider or closer view.