# RhinoCommonExtensionMethods class

Namespace: [Grasshopper2.Extensions](https://developer.rhino3d.com/api/gh2/namespace/grasshopper2.extensions.md) · Assembly: [Grasshopper2](https://developer.rhino3d.com/api/gh2/assembly/grasshopper2.md)

```cs
public static class RhinoCommonExtensionMethods
```

Some extension methods for various RhinoCommon types.

## Methods

- [AddSphere](https://developer.rhino3d.com/api/gh2/type/grasshopper2.extensions.rhinocommonextensionmethods/addsphere.md): (2 overloads, static)
- [FindCusps](https://developer.rhino3d.com/api/gh2/type/grasshopper2.extensions.rhinocommonextensionmethods/findcusps.md): (2 overloads, static) Find parameters where cusps occur within the given interval. Note that the limits of the interval are rejected as possible cusp locations.
- [FocusWindowNAH](https://developer.rhino3d.com/api/gh2/type/grasshopper2.extensions.rhinocommonextensionmethods/focuswindownah.md): (static) Make sure the Rhino window hosting the specified document has focus.
- [GetContinuityLevel](https://developer.rhino3d.com/api/gh2/type/grasshopper2.extensions.rhinocommonextensionmethods/getcontinuitylevel.md): (static) Evaluate the level of discontinuity at a given curve parameter.
- [HasSelectableObjects](https://developer.rhino3d.com/api/gh2/type/grasshopper2.extensions.rhinocommonextensionmethods/hasselectableobjects.md): (static) Gets whether this document contains any selectable (i.e. non-hidden and non-locked) object of the given type.
- [Invert](https://developer.rhino3d.com/api/gh2/type/grasshopper2.extensions.rhinocommonextensionmethods/invert.md): (static) Create a new material with inverted back and front face properties.
- [MakeClosedViaLine](https://developer.rhino3d.com/api/gh2/type/grasshopper2.extensions.rhinocommonextensionmethods/makeclosedvialine.md): (static) Close a curve by inserting a line segment from the end to the start point.
- [RedrawAndReturnImmediately](https://developer.rhino3d.com/api/gh2/type/grasshopper2.extensions.rhinocommonextensionmethods/redrawandreturnimmediately.md): (static) Redraw all Rhino viewports. All GH code should use this method rather than [ViewTable.Redraw()](https://mcneel-apidocs-rhinocommon-7f6eb10c6967.herokuapp.com/api/rhinocommon/type/rhino.docobjects.tables.viewtable/).
- [Reflex](https://developer.rhino3d.com/api/gh2/type/grasshopper2.extensions.rhinocommonextensionmethods/reflex.md): (static) Get the reflex arc.
- [RegionIndices](https://developer.rhino3d.com/api/gh2/type/grasshopper2.extensions.rhinocommonextensionmethods/regionindices.md): (static) Find all the indices of input curves that went into a specific region.