• PointOnLine2[cnum, point, axis] models a spatial slider in which point is constrained to lie on axis.
• PointOnLine2 constrains two degrees of freedom.
• axis may be specified by a Modeler3D Line, Plane, or Axis object.
• The two equations constrain a vector from point to the origin of axis to be orthogonal to a pair of vectors that are mutually perpendicular to axis.
• See also: PointOnCircle2, PointOnPlanes2, SetConstraints, SysCon.