## Introduction

The geometry menu contains components for working with geometry.

### Components

###### Fold Angle

Given four points ABCD, and planes ABC, and ABD, where points C and D represent points on each plane, point C represents a point on plane ABC and point D a point on plane ABD, the angle from the reference plane ABC to plane ABD about fold line AB is calculated.

###### Brep Closest Point

Given a reverence point, the point on a given Brep closest to this reference point is obtained. The normal or tangent vector to the brep at the closest point is returned. Additional information about the component/s of the brep at the closest point is also returned.

###### Master Slave

For a list of geometry inputs, for a given tolerance, the master geometry is obtained. The master geometry is defined as being a unique instance of a geometry. Any other geometry that is identical based on the user defined tolerances is defined as a slave to the master. The index of the slave with respect to the original source geometry is returned in addition to the slave index of the newly created master geometry

###### Master Slaves

For a list of master geometry and a list of slave geometry, any slave geometry that falls within the tolerance of the user defined source master geometry is defined. If a master slave relationship is identified, only the master and slave geometry is output .

###### Model Units

The component allows the user to change the rhino document units. A model can be scaled or not scaled due to changes to the document units.

###### Geometry Order

Geometry can be sorted based on user defined geometry systems, Cartesian, cylindrical and spherical. A local or default world plane can be used to reference the ordering. Both global and local coordinates are returned in Cartesian, cylindrical and spherical systems.

###### Geometry Replace

Given a reference geometry in rhino, the geometry may be replaced by new geometry defined by the user. The original reference GUID of the geometry is unchanged including the attributes of the object. The only thing changed is the geometry itself.

###### Transform Plane Rotation

Given a Cartesian coordinate system x,y,z, defined by a user defined plane, a new local Cartesian system x”,y”,z” and plane may be defined by three successive angular rotations. Firstly, the Yaw angle about the original z axis of the reference plane is defined, this gives the plane with coordinate Cartesian axes x’,y’,z. Next a new transformation for an angular rotation of Pitch about the Cartesian y’ axes is given to give the new axis system x”,y’,z’. Next an angular rotation of Roll about the x” axis is given to give the final coordinate axis system of x”,y”,z”.