CONSTRUCT TRANSFRM ROTATE [tnam] definition

    

This command is used to define a rotational transformation.

tnam = name of the transformation

definition = definition of the transformation (see below).

Definition Comments

pnam1 pnam2 angle The transformation is defined by specifying an axis of rotation from point `pnam1' to point `pnam2' and giving an `angle' (in degrees) through which coordinates are to move about this axis. Note that the right hand rule defines the positive direction of rotation (see figure below). The points may be identified by name or picked using the graphics cursor.

pnam1 pnam2 pnam3 The transformation is defined as a rotation about the origin point (`pnam1') such that a line from `pnam1' through point `pnam2' will rotate to a new position through point `pnam3'. The points may be identified by name or picked using the graphics cursor.

pnam1 pnam2 pnam3 pnam4 The transformation is defined by specifying an axis of rotation from point `pnam1' to point `pnam2'. The angle of rotation is defined such that the plane `pnam1', `pnam2', `pnam3' is rotated about the axis to pass through point `pnam4'. The points may be identified by name or picked using the graphics cursor.

This command is used to define rotations for use in GEOMETRY SWEEP, GEOMETRY COPY and GEOMETRY MOVE commands.

 

Figure 2.58: Definition of the direction of rotation

Examples:

1.

CONSTRUCT TRANSFRM ROTATE TR2 P1 P2 22.5

This defines a rotation, called TR2, of 22.5 deg around an axis defined by P1 and P2.

2.

CONSTRUCT TRANSFRM ROTATE P1 P2 P3

This defines a rotation using point P1 as its origin and such that point P2 would move to point P3. As no name is specified for the transformation a name will be automatically generated.

See also the following commands

'GEOMETRY COPY'
'GEOMETRY MOVE'
'GEOMETRY SWEEP'