Apple Motion 5.1.1 - Manual (Page 908)

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3D compositing overview
Motion includes a robust set of tools for creating projects that display objects in a true three-
dimensional space. You can arrange objects in a 3D environment so they intersect and interact
with one another. You can also employ cameras and lighting, and apply related effects such as
depth of field, shadows, and reflections.
Real-world coordinates
3D compositing introduces a number of new concepts to the art of motion graphics. At first
glance, these concepts might seem daunting. However, because you move around in a real three-
dimensional world, you’ll likely find the virtual 3D world of the Motion Canvas intuitively familiar.
The position of any object in the real world can be described using a simple coordinate system.
For example, you might describe your computer’s position as being four feet across from the
door, three feet up from the floor, and five feet in front of the window. In a coordinate system, the
three numbers used to describe an object’s position correspond to a coordinate axis. The place
where the zero values along each axis meet is called the origin. In this example, the X equals 4, Y
equals 3, and Z equals 5.
Coordinates and object position in space
The location of an object in Motion can be described in these terms as well. The coordinate
system used by Motion specifies the center of the Canvas as 0, 0, 0. Moving an object to the left
subtracts from the X value, while moving to the right adds to the X value. Moving an object up
adds to the Y value, and moving an object down subtracts from the Y value. Moving an object
closer adds to the Z value, while moving further away subtracts from the Z value. The main
difference between a 2D scene and a 3D scene is that in a 3D scene, you can change your point
of view, so that moving an object up doesn’t always mean increasing its Y Position value.
Note: In a new project, the Canvas is oriented with the Z axis pointing straight at you. This
orientation preserves the traditional two-dimensional orientation of the X and Y axes, which span
the default Canvas from left to right (X) and top to bottom (Y).
3D compositing
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