NAME

DoTransformMatrix − Create a transformation matrix geometric transformation object

SYNOPSIS

C:

DtObject DoTransformMatrix(matrix, comptype)
DtMatrix4x4 matrix;
DtCompType comptype;

FORTRAN:

INTEGER∗4 DOTMX(MATRIX, COMTYP)
REAL∗8 MATRIX(4,4)
INTEGER∗4 COMTYP

DESCRIPTION

DoTransformMatrix creates a transformation matrix geometric transformation object.  DoTransformMatrix is one of the geometric transformation objects whose value is used to determine the current transformation matrix.  Unlike other geometric transformation objects that always preconcatenate their values with the current transformation matrix so they apply first, DoTransformMatrix allows the user to decide how it affects the current transformation matrix. 

The parameter matrix specifies an arbitrary modeling transformation to be combined with the current transformation matrix.  The parameter comptype specifies the way matrix will be combined with the current transformation matrix.  Possible values for comptype are:

DcReplace <DCREPL>
matrix replaces the current transformation matrix. 

DcPreConcatenate <DCPREC>
matrix is preconcatenated to the current transformation matrix; i.e., this transformation applies before any previous transformations. 

DcPostConcatenate <DCPSTC>
matrix is postconcatenated to the current transformation matrix; i.e., this transformation applies after any previous transformations. 

Note that Doré matrices are formed assuming that points are represented as column vectors. See Chapter 7, Doré Matrix Transformations in the  Doré Reference Manual for more information. 

The parameter matrix can be an arbitrary 4x4 matrix, but singular matrices (non-invertible) will cause fatal errors. 

SEE ALSO

DoLookAtFrom(3D), DoRotate(3D), DoScale(3D), DoShear(3D), DoTranslate(3D)

September 02, 1992