Limit Distance Constraint
Mode: Object and Pose modes
Panel: Constraints (Object context and sub-context, F7, or Editing context, F9, when in Pose mode)
The Limit Distance constraint forces its owner to stay either farer than, nearer than, or exactly at a given distance from its target. In other words, the owner’s location is constrained either outside, inside, or at the surface of a sphere centered on its target.
When you specify a (new) target, the Distance value is automatically set to correspond to the distance between the owner and this target.
- This constraint uses one target, and is not functional (red state) when it has none.
- (Bone Target)
- When using a bone target, you can chose where along this bone lays the target point, using the Head/Tail numeric field.
- This numeric field sets the limit distance, i.e. the radius of the constraining sphere.
- When clicked, this small button will recalculate the Distance value, so that it corresponds to the actual distance between the owner and its target (i.e. the distance before this constraint is applied).
- Clamp Region
- The Limit Mode drop-down menu allows you to chose how to use the sphere defined by the Distance setting and target’s center:
- Inside (default)
- The owner is constrained inside the sphere.
- The owner is constrained outside the sphere.
- The owner is constrained on the surface of the sphere.
A Limit Distance constraint applied to
Owner empty, using
Target_1 empty as target.
The yellow dashed circle materializes the sphere defined by the Distance value and the target center.
In (The Limit Distance constraint just added), as Distance is set to the distance between
Target_1, the owner does not move.
The two green constrained bones have a Limit Distance constraint, with the same target bone (the selected one). In the three pictures, the yellow dashed (arcs of) circles materializes their respective Distance spheres. In (Inside clamp region, moving the target nearer…), both owner bones are inside their sphere, everything’s perfect… In (Inside clamp region, moving the target farer…), the target is moved so that both owner bones are outside of their clamp sphere. As you can see, the unconnected (though parented) bone moves, to stay inside its sphere, whereas the connected bone cannot move, and hence is not effectively constrained…