There are different ways of calculating rotation
axes, depending on the reference geometry you select.
From the Model section of the action bar, click Rotation.
Select the Definition mode in the list.
Axis-Angle (default mode): The rotation axis is defined by a linear
element. The angle is defined by a value that can be modified in the dialog
box or in the 3D area using the handles.
Axis-Two Elements: The rotation axis is defined by a linear element and the angle is defined by two geometric elements (point, line or plane).
Axis/point/point: The angle between the vectors is defined by the
selected points and their orthogonal projection onto the rotation
axis.
Axis/point/line: The angle between the vector is defined by the selected point and its orthogonal projection onto the rotation axis and the selected line.
Axis/line/line: The angle between the direction vectors of the projection is defined by the two selected lines in the plane normal to the rotation axis. In case both lines are parallel to the rotation axis, the angle is defined by the intersection points of the plane normal to the rotation axis and these lines.
Axis/line/plane: The angle is defined between the selected line and the normal to the plane.
Axis/plane/plane: The angle is defined between the lines normal to the two selected planes.
Three Points:
The rotation is defined by three points.
The rotation axis is defined by the normal of the plane
created by the three points passing through the second point.
The rotation angle is defined by the two vectors created
by the three points (between vector Point2-Point1 and vector
Point2-Point3).
The orientation of the elements is visualized
in the 3D area by a red arrow. By default, it is the direction normal to
the feature. The angle is automatically recomputed if you invert the orientation.
.