Working with the Construction Plane
	A construction plane is like a tabletop that the cursor normally moves on. It can be set in different ways to aid with modeling.
Part of	Rhinoceros , Rhinoceros for OSX
Part Type	Method
Screenshot

Introduction to the Construction Plane

The construction plane, or CPlane, represents the local coordinate system for the viewport and can be different from the world coordinate system. There is a grid on the CPlane.

The plane can be set to any orientation, and each viewport’s construction plane is independent of those in other viewports. It is important to pay attention to the CPlane's orientation because lines, points, or objects often need to be in the same plane in order for certain commands to work (and generally results in a cleaner model). Commands such as PlanarSrf , which creates a surface from a curve, requires that the curves be in the same plane.

Set CPlane Origin

Because each CPlane has a grid, moving the origin of the CPlane will move the origin of the grid. This is useful if snapping to the grid is turned on as it aids in modeling more precisely.

Set CPlane by X-axis

This aligns the X-axis of the grid to any axis chosen in the model. It is useful for rotating the CPlane.

Set CPlane to Object

Setting the CPlane to a surface ensures that the subsequent objects are in plane with that surface. This may also rotate the CPlane.

Saving the CPlane

The position of the CPlane can be saved for easy access later.

The CPlane Toolbar

The options for the CPlane can be accessed in three ways. The icon to look for on the Main Toolbar is a grid with X- and Y-axes. If the CPlane tab is not shown, right click a blank area of the Toolbar and select "CPlanes" from the drop-down menu. The second way to access the options is to right-click the Viewport tab and highlight "Set CPlane" so that the options menu appears. The third way is to enter the CPlane command into the command prompt and entering in the name of the option.

Set CPlane Origin

To move the origin of the CPlane anywhere in the 3D space, click on the Set CPlane Origin icon (if the command prompt is used, setting by origin is the default option). Then, you can set the origin and orientation of the construction plane in the active viewport. To draw on the new construction plane, it is useful to make sure Project is turned on so that objects are projected to the CPlane. Remember that the construction plane of each viewport is independent from that of the other viewports. To link construction planes, enter "A" while in the "Set CPlane Origin" command settings to change "All" to "Yes." To unlink construction planes, enter "A" again the next time the command is used.

Set CPlane by X-axis

Setting the construction plane by axis allows the CPlane to be rotated and oriented according to an axis. To do this, click on the "Set CPlane by X-axis" icon (or select the "3Point" option if using the CPlane command). First, click on the origin of the contruction plane. Then, choose another point with which the X-axis aligns. Now, the construction plane's X-axis has been moved.

Set CPlane to Object

Setting the construction plane by object constrains the plane so that it is tangent to the surface of the object selected. This is especially useful when the plane is not orthogonal in the X, Y, and Z directions. To do this, click on the "Set CPlane to Object" icon (or select the "Surface" option if using the CPlane command). Then, choose the surface of the object that will define the construction plane.

Saving the CPlane

The construction plane's position can be saved for later use. When the plane is oriented the way you want it, make sure you are in the correct active viewport, and click on the "Save CPlane by Name" icon, or use the NamedCPlanes command. Enter a name for the CPlane and save it. To access saved CPlanes, use the NamedCPlanes command, choose the name of the CPlane, and click Restore.