The SG_Plane node represents a reference geometrical plane. This is useful in feature-based modeling, or as construction geometry. The SG_Plane structure itself has no parameters. The intrinsic node orientation is the normal vector (the a, b, c coefficients) of the plane, and the d coefficient is obtained from the node's world coordinates.
The SG_PlaneNew() function creates a new reference plane.
The SG_Plane node class first appeared in Agar 1.6.0.