nentselp

Provides similar functionality to that of the
*nentsel* function without the need for user
input

(nentselp[msg] [pt])

Arguments

*msg*-

A string to be displayed as a prompt. If the*msg*argument is omitted, the Select object prompt is issued. *pt*-
A selection point. This allows object selection without user input.

Return Values

*nentselp* function returns a 4W4
transformation matrix, defined as follows:

The first three columns of the matrix specify scaling and rotation. The fourth column is a translation vector.

*homogeneous
coordinates,* where the fourth element of the point vector is a
*scale factor* that is normally set to 1.0. The
final row of the matrix, the vector [*M*_{30}*M*_{31}*M*_{32}*M*_{33}],
has the nominal value of [0 0 0 1]; it is currently ignored by the
functions that use this matrix format. In this convention, applying
a transformation to a point is a matrix multiplication that appears
as follows:

This multiplication gives us the individual coordinates of the point as follows:

As these equations show, the scale factor and the last row of the matrix have no effect and are ignored.