Distance Constraint
The Distance Constraint makes an object stay close, far, or exactly at a specific distance to another object.
How to create a Distance Constraint
Add a Distance Constraint to an object
Use the Constraints section of the Inspector to add a Distance Constraint to an object.
Choose a target
Use the new constraint’s fly-out menu to select a target for this constraint.
Test that the Distance Constraint is working
Moving the target object now causes the constrained object to stay close (which is the default mode).
Strength
The Strength property determines how much the constrained object is affected.
A Strength of 0% means the constraint won’t have any effect.
Distance
The distance that the object will be constrained from the target object. A red constraining circle is drawn on the stage to represent this value.
Mode
Closer
The owner is constrained closer than the Distance setting. In other words, the owner is constrained inside the constraining sphere.
Further
The owner is constrained further than the Distance setting. In other words, the owner is constrained outside the constraining sphere.
Exactly
The owner is constrained exactly at the distance of the constraining sphere.