Rotate structural entities around a certain axis

The 'Rotate' icon is situated on the 'Geometry manipulations' toolbar:

The rotation of the member can be done by vectors. You need to determine 3 points:

• 1st point is the center of rotation (common point for both vectors);
• 2nd point is the start point (this point determines the first vector);
• 3rd point is the end point (this point determined the second vector).

However, in a 3D environment, there’s a choice between three more options how to rotate a member:

The three possibilities are:

• Working plane normal vector: this means that the rotation axis (= a direction vector) is defined perpendicular to the active working plane. The active working plane can be chosen at the bottom of the command line:


If for instance the active working plane = Plane XY, the rotation will be done around the Z axis of the GCS (or active UCS). Furthermore, only the center of rotation has to be defined.

• Define axis by cursor: in this case 2 points on the rotation axis have to be selected, or their co-ordinates have to be entered on the command line.

It might be convenient to select the first point with the cursor, and to use subsequently relative co-ordinates. E.g. “@0 1 0“: the ‘at’-sign indicates that the co-ordinates (0 1 0) have to be taken relatively with regard to the first point.

• Enter custom axis vector: in this case the rotation axis is defined as a direction vector with regard to the origin (0 0 0). If for instance 0 / 0 / 1 is filled in, it means that the Z axis of the GCS (or active UCS) has been chosen as rotation axis.