CRETFM ( matrix, transf, ifail )
================================

  Creates a general transformation from the given matrix.

Receives:
  double                    matrix[16]     --- transformation components

Returns:
  KI_tag_transform         *transf         --- the transformation
  KI_cod_error             *ifail          --- failure code

Specific errors:
  KI_wrong_transf           determinant is zero
  KI_sc_factor_le_0         scale must be greater than zero
  KI_bad_component          array positions 12, 13, 14 must be zero

Description:
  The array 'matrix' contains the components that make up the
  transformation.

  The matrix operates as a post-multiplier on row vectors containing
  homogenous coordinates thus:

  (x',y',z',s') = (x,y,z,s) T

  where the conventional 3-d coordinates are

  (x/s,y/s,z/s).

  The matrix thus consists of

      (             , 0 )
      (      R      , 0 )
      (             , 0 )
      ( Tx, Ty, Tz,   S )

  R = a non singular transformation matrix. This matrix contains the rotation,
      reflection, local scaling and shearing components.
  T = a translation vector.
  S = a global scaling factor. It has to be greater than zero.

  'matrix' should be filled as follows:

           Positions in array         Contents
           ------------------        ----------
             0 through 2,           transformation elements r    r    r
                                                             11   21   31

             4 through 6,                   "         "     r    r    r
                                                             12   22   32

         and 8 through 10                   "         "     r    r    r
                                                             13   23   33
             3,7, and 11            translation vector

            12 through 14           0.0

                 15                 scale



  Note that only rotation and translation are permitted in transformations
  attached to instances.

  Note that transformations where R is non-orthogonal (contains shearing or
  local scaling) cannot be applied to many entities (see APPTRA).