Clamp To Constraint

The Clamp To constraint snaps an object or bone to a Curve. Specifically, it works as follows:

  • If no explicit Main Axis is chosen, the constraint picks one automatically based on the longest side of the Curve’s bounding box.

  • Using this axis, it compares the original coordinate of the object or bone to the minimum and maximum coordinates of the Curve, and remaps it to the range 0-1 accordingly.

  • This remapped coordinate is then used as a “curve time” to determine the position along the Curve, where a value of 0 corresponds to the first control point and 1 to the last.

Unless the Curve is a perfectly straight line, the object’s/bone’s coordinate along the Main Axis will likely change.

If the object or bone moves along the Curve in the opposite direction than the expected one, use Switch Direction to flip the order of the Curve’s control points.

Important

While the object’s/bone’s original coordinate is evaluated in world space, the Curve’s bounding box is evaluated in the Curve’s local space.

This means that, if the Curve originally stretched from -5 to 10 on the global X axis but was then moved, rotated, and scaled so that it now stretches from 20 to 90 on the global Z axis, the Main Axis will still be chosen as X, and the object/bone still needs to move from -5 to 10 on the global X axis to be successfully moved along the Curve.

For the most intuitive results, keep the Curve object at the default rotation.

Note

Bézier handles and control point radii are included in the calculation of the bounding box.

See also

The Follow Path Constraint can not just position an object/bone on a Curve, but also orient it along the Curve’s direction.

Options

../../../_images/animation_constraints_tracking_clamp-to_panel.png

Clamp To constraint.

Target

The Curve object to snap to.

Main Axis

The axis for determining the constraint owner’s coordinate and the Curve’s minimum/maximum coordinates.

Cyclic

When disabled, the constraint owner will stop at the start/end of the Curve when it leaves the range of the Curve’s bounding box. When enabled, it will jump to the opposite side and begin another run along the Curve.

This option is mainly useful for Curves that are also cyclic (closed).

Influence

How strongly the constraint affects the object.

Example