• $MechUseMinimalRotation can be set to True to cause Modeler3D to use a minimal rotation formulation to transform axes that have no specified reference direction.
• The default setting of $MechUseMinimalRotation is False.
• The minimal rotation formulation rotates the given axis through the minimal rotation required to be aligned with + Z.
• The minimal rotation formulation produces a symbolic result that is much simpler, but becomes singular when the axis is pointed in the - Z direction.
• The default formulation uses the Step function to generate a more complex piecewise continuous result that is nonsingular for any configuration.
• Whether or not the symbolic axis transformation becomes singular is irrelevant if axes are specified entirely numerically, as they typically are.
• See also: ReferenceDirection.