definition of a quadric surface. Ten real values of the matrix that defines the quadric surface in projective space. Ordered Q11, Q12, Q13, Q22, Q23, Q33, P1, P2, P3, R. Takes a units attribute of dimension reciprocal length. R is scalar. P has dimension reciprocal length, and the given units. Q has dimension reciprocal length squared, and units the square of those given. An optional description of the form of the quadric surface: Path to an :ref:`NXtransformations` that defining the axis on which the orientation of the surface depends.