2.2.5 Axes The axis object is used by Mech to reference an axis in 2D or 3D space. An axis object is specified by origin and direction. Optionally, 3D axis objects may have a reference direction specified. The reference direction is a vector that is not parallel to the direction of the axis. The reference direction is used by some Modeler3D constraints to control rotation about the axis.
An axis object may have the head Axis, Line, or Plane. If a Line is used to specify an axis object, the origin and direction of the Line are used as the origin and direction of the axis. Because a Line object has no specific reference direction, a Line should not be used in place of a Modeler3D axis object in a function where the reference direction is relevant.
If a Plane is used to specify an axis object, the origin of the Plane is used as the origin of the axis, the normal direction of the Plane is used as the direction of the axis, and the line from point1 to point2 on the Plane is used as the reference direction of the axis.
Any Mech function that calls for an axis object accepts any of the following syntax. 2DMethods of defining 2D axis objects. 3DMethods of defining 3D axis objects. Assuming that the appropriate body object definitions have been made, any axis with origin and direction specified with coordinates on a single body or multiple bodies can be referenced with a combination of global points, local points, or local point numbers. The following example shows several axis objects that are functionally identical. This loads the Modeler2D package. Local points are defined on the two bodies. Here are three functionally identical axis definitions. Here are three more identical axis definitions.
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