## Planes

Planes are represented by a Plane structure. Planes can be thought of as a zero-based, one-dimensional list containing four elements: the plane’s origin (point3D), the plane’s X axis direction (vector3d), the plane’s Y axis direction (vector3d), and the plane’s Z axis direction (vector3d).

```
plane contains [pointOrigin, vectorX, vectorY, vectorZ]
```

It is easy to forget that there is a specific geometric relationship between the axes. With Planes, the Y axis is automatically oriented 90-degrees to the X axis. The X axis is the only axis that can be easily defined. The Y axis is made orthogonal to the X vector, and the direction of the Z axis is computed from the cross-product of the other two vectors.

Planes can be constructed in a number of ways. One common function is `PlaneFromPoints`

:

```
import rhinoscriptsyntax as rs
corners = rs.GetRectangle()
if corners:
plane = rs.PlaneFromPoints(corners[0], corners[1], corners[3])
print plane[0] # origin point
print plane[1] # x-axis vector
print plane[2] # y-axis vector
```

Planes can also be created using the `CreatePlane()`

, PlaneFromFrame, PlaneFromNormal, and PlaneFromPoints functions.

Plane also have a number of properties that can be used to get or set the individual values in the Point object. In the example below the `.Origin`

, `.XAxis`

, `.Yaxis`

, `.Zaxis`

are used:

```
import rhinoscriptsyntax as rs
plane = rs.PlaneFromPoints([-2,-5,0],[1,2,0],[-3,3,0])
print plane.Origin # origin point
print plane.XAxis # x-axis vector
print plane.YAxis # y-axis vector
plane.Origin = rs.CreatePoint(3,4,5) # Changes the origin of the plane.
print plane.Origin
print plane.XAxis # x-axis vector
print plane.YAxis # y-axis vector
```

To change origin of a Plane, simply assign a new value to the `.Origin`

property.

Use the Python `for`

iterator to walk through each point coordinate in succession:

```
for p in plane:
print p
```

RhinoScriptSyntax contains a number of functions to manipulate planes. See Lines and Planes for details.

Also, please see the Python primer Section 8.5 Planes.