Dummy Helper
A Dummy helper object is a wireframe cube with a pivot point at its geometric center. It has a name but no parameters, you can't modify it, and it doesn't render. Its only real feature is its pivot, used as a center for transforms. The wireframe acts as a reference for transform effects.
Create panel > 
(Helpers) > Standard > Object Type rollout > Dummy- Default menu: Create menu > Helpers > Dummy
- Alt menu: Objects menu > Helpers > Dummy
The dummy object is used primarily in hierarchical linkages. For example, you can use a dummy object as a center of rotation by linking a number of different objects to it. When you rotate the dummy, all of its linked children rotate with it. A dummy is often used this way to animate linked motion.
Another common usage of a dummy object is in the animation of target cameras. You can create a dummy and position a target camera within the dummy object. Then you can link both the camera and its target to the dummy, and animate the dummy with a path constraint. The target camera will follow the dummy along the path.
Dummy objects are always created as cubes. You can change the proportions of dummies by using non-uniform scaling, but avoid this on dummies that are within a hierarchical linkage; this can introduce unexpected results.
Procedures
To create a dummy object:
- Click Dummy and drag a cube to any convenient size.
Once added the dummy helper's size cannot be modified using the Modify panel. It can be modified using the Select and Rotate or Select and Resize tools, or by using MAXScript. Select the dummy helper and use this script in the listener window, setting the values for x, y, and z:
- $.boxsize = [x,y,z]
Interface
Dummy objects don't have any parameter rollouts or settings.