2.2.4 PlanesThe Plane object is used by Modeler3D to reference a planar surface in 3D space. A Plane is defined by three points and has a specific origin, normal direction, and reference direction (see Axis). The first of the three points is the origin, and the vector from the first point to the second point is the reference direction. The third coplanar point cannot be colinear with the first two points. The positive normal is given by the cross product of the vector from the first point to the second point and the vector from the first point to the third point. Because a Plane object possesses the properties of direction and location, it can be used in place of a vector object or an axis object in any Mech function that calls for a vector or an axis. If a Plane object is used to specify direction, the normal direction is used as the direction vector. Any Modeler3D function that calls for a vector or axis object accepts any of the following syntax. 3DMethods of defining plane objects. Assuming that the appropriate body object definition has been made, a plane spanning any one, two, or three bodies can be referenced with a combination of global points, local points, or local point numbers. The following example shows several plane objects that are functionally identical. This loads the Modeler3D package. Local points are defined on the two bodies. Here are two identical plane definitions. Here are three more identical plane definitions.
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