Using the Unenforce Constraints Button to Manipulate 3-D Joint Objects
You can specify that the kinematic constraints of a joint object that you select are not enforced in the 3-D Workspace as you build your model. Joints with unenforced kinematic constraints appear in pink in the 3-D Workspace and their initial conditions are not shown in the 3-D Workspace as you build your model.
You may want to perform this task if, for example, you are creating a closed-loop model in the 3-D Workspace and you need the joint to remain in a specific position as you are building and laying out your 3-D model.
To unenforce constraints to manipulate a joint object:
In the 3-D Workspace, select the sphere that represents a joint.
Click Unenforce Constraints (
) located below the 3-D Workspace. The joint object now appears in pink.
Note: The joint object initial conditions do not appear in the 3-D Workspace until you assemble the model by running a simulation or clicking 3-D View Update (
Consider a double pendulum 3-D model that contains a revolute joint with unenforced kinematic constraints and a second revolute joint with enforced kinematic constraints. If you change the initial angle of the joint with enforced kinematic constraints, the joint with the unenforced kinematic constraints remains in its original position while the joint with enforced kinematic constraints is shown at the new initial angle. To display all of the new initial conditions in the 3-D Workspace, you must assemble your model by running a simulation or clicking 3-D View Update (
The unenforce constraints button does not affect the actual initial conditions specified for joint components in the Properties tab (
); it affects the initial conditions shown in the 3-D Workspace for visualization purposes only.
Initial conditions for other joints with enforced kinematic constraints are shown in the 3-D Workspace, but do not affect any joints with unenforced kinematic constraints.
When a joint is unassembled using Unenforce Constraints (
), its initial conditions are set to Ignore.