Inspired 3D Character Setup: Basic Building Blocks of Effective Character Creation

Michael Ford and Alan Lehman take us through the step-by-step process of planning the setup of a 3D character. While these steps may sound time consuming the authors assure us it will pay off in the end! The second of several excerpts from the book, Inspired 3D Character Setup.

By Mike Ford and Mike Ford | Friday, July 25, 2003 at 12:00 am

Posted In | Magazines: VFXWorld

[Figure 5] The joint’s translation manipulator in object space takes into account how the object’s rotational axis is oriented.

World Space Translation
An object’s translation in world space is relative to the global center of the world coordinate system, known as the origin. (See Figure 6.) Any object manipulated in world space will translate on the axis that is the same as the world coordinate system, regardless of what transformations have accumulated on it or its parents. If you have multiple objects selected, they will all translate relative to the world coordinate system regardless of a particular object’s place in a hierarchy or transformation.

[Figure 6] The joint translates relative to the global center of the world space coordinate system.

Local Space Translation
Local space translation is aligned to the rotation axis of the object’s parent. As you can see in Figure 7, the translation manipulator of the selected joint is lined up with the rotational axis of its immediate parent. If the object has no parent, then the local space of an object is the same as the world space. If you select multiple objects and translate them in local mode, they will all translate relative to their immediate parent’s rotational axis.

When you use a manipulator to transform an object in Maya, you’re only changing the way in which you interact with the object — the values that are calculated are always based on how the software calculates its transforms. For example, if you create a sphere and rotate it 90 degrees in Y, you have changed the direction in which the Z and X axes are oriented. If you try to interactively translate the sphere using the Z arrow on your manipulator in object mode, you’re adding values to the X translation channel, not the Z translation channel. Be very careful when you translate and rotate objects using manipulators. Your movement may look correct, but the results of your transformations may not match the visual feedback you see in the manipulator. In this case, for an accurate display of your manipulator, you would have to switch to local mode. Try the same exercise again and you’ll see the difference. (For more on channels, see Chapter 8, “Attributes, Channels and Constraints.”)