Editing Physics Asset Constraints

This how-to covers the procedures for editing the Constraints of a Physics Asset.


Below are a number of common procedures, and steps, associated with editing Physics Constraints in the Physics Asset Tool.

Editing Physics Constraints

The use of Physics Constraints is covered in the Physics Constraints User Guide and their properties are covered in the Physics Constraint Reference . This section will only cover workflows that are specific to the Physics Asset Tool or ones that have deviated substantially from the norm.

  1. Enable Constraint Editing Mode


  2. Select a Physics Constraint in the Viewport or in the Hierarchy Pane.

  3. Move and rotate the Physics Constraint using the Translation and Rotation to create the rotational point of the "joint" the Physics Constraint will form.

  4. Edit the Physics Constraint's properties in the Details Pane.

    You can switch Swing1, Swing2, and Twist from Limited to Locked quickly by using the "1", "2", and "3" keys respectively. The "4" key can be used cycle through them setting one to limited and the other two to locked.

  5. Save


See the Physics Asset Tool Reference for more information on the properties in the Physics Asset Tool.

Aligning Physics Constraints

If you are using the Physics Constraint's Linear or Angular limits, you will be able to see their alignment:


By then translating and rotating the Physics Constraint, you can align the limits to give the desired results. In the most basic of terms, when a Physics Constraint is limited, you can see a yellow line suspended in a green arc or cone structure. The line will be "constrained" within this arc or cone.

For more information on Physics Constraints and their properties, see the Physics Constraints User Guide .

Copying Physics Constraints

While in either mode, properties from one Constraint can be copied to other Constraints:

  1. Select Constraint you wish to copy data from.

  2. Press Ctrl + C.

  3. Select Constraints you wish to apply data to.

  4. Press Ctrl + V.

Deleting Physics Constraints

There is no easy way to recreate a Physics Constraint, be mindful of this when deleting them.

  1. Enable Constraint Editing Mode


  2. Select the Physics Constraint you wish to delete.

  3. Press the Delete key.

Recreating a Physics Constraint

There is no easy way to recreate a Physics Constraint, be mindful of this when deleting them.

Physics Constraints are only created on generation of a Physics Body and are only generated upstream. So if you remove a Physics Constraint from the shoulder, you would have to remove the upper arm Physics Body (which will remove the elbow Physics Constraint), then re-create the upper arm Physics Body. This would create the shoulder Physics Constraint, but not the elbow Physics Constraint, so you would have to continue this process down the arm.

Constraint Snapping

Snapping a Physics Constraint will take the blue locator for the Physics Constraint and snap its location and rotation to the red one's location and rotation.

You can snap the currently selected Physics Constraint(s) by using the Snap Constraint


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