• Parallel2[cnum, vector1, vector2] constrains the vectori to be parallel in 3D space.
• Parallel2 constrains two degrees of freedom.
• Parallel2 is not sensitive to the sign of the vectori.
• The constraint is satisfied if the two vectors are pointing in exact opposite directions.
• See also: Orthogonal1, Parallel1, SetConstraints, SysCon.