# HalfEdge class

Namespace: [Grasshopper2.Geometry.HalfEdges](https://developer.rhino3d.com/api/gh2/namespace/grasshopper2.geometry.halfedges.md) · Assembly: [Grasshopper2](https://developer.rhino3d.com/api/gh2/assembly/grasshopper2.md)

```cs
public class HalfEdge
```

Represents a halfedge in the half-edge mesh data structure. Derived from Plankton, (c) 2013 Daniel Piker and Will Pearson, licensed LGPL v3 or later.

## Fields

- [Face](https://developer.rhino3d.com/api/gh2/type/grasshopper2.geometry.halfedges.halfedge/face.md): Index of the first face adjacent to this edge.
- [Next](https://developer.rhino3d.com/api/gh2/type/grasshopper2.geometry.halfedges.halfedge/next.md): Index of the next half edge.
- [Prev](https://developer.rhino3d.com/api/gh2/type/grasshopper2.geometry.halfedges.halfedge/prev.md): Index of the previous half edge.
- [Vertex](https://developer.rhino3d.com/api/gh2/type/grasshopper2.geometry.halfedges.halfedge/vertex.md): Index of the vertex at the start of the edge.

## Properties

- [IsUnset](https://developer.rhino3d.com/api/gh2/type/grasshopper2.geometry.halfedges.halfedge/isunset.md): Whether this halfedge is unset, meaning it has no start vertex index.
- [Unset](https://developer.rhino3d.com/api/gh2/type/grasshopper2.geometry.halfedges.halfedge/unset.md): (static) Gets an unset HalfEdge. Unset halfedges have a start vertex index of -1.