# HermiteSurface class

Namespace: [Rhino.Geometry](https://developer.rhino3d.com/api/rhinocommon/namespace/rhino.geometry.md) · Assembly: [RhinoCommon](https://developer.rhino3d.com/api/rhinocommon/assembly/rhinocommon.md)

```cs
public class HermiteSurface : IDisposable
```

Create an ON_NurbsSurface satisfying Hermite interpolation conditions at a grid of points.

## Constructors

- [HermiteSurface](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/ctor.md): (2 overloads) Initializes a new [HermiteSurface](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface.md) instance.

## Finalizer

- [~HermiteSurface](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/finalize.md): Passively reclaims unmanaged resources when the class user did not explicitly call Dispose().

## Properties

- [IsValid](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/isvalid.md): Returns true if the all of values in all of the internal data structures contain valid values, false otherwise.
- [UCount](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/ucount.md): Gets the number of parameters in the "u" direction.
- [VCount](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/vcount.md): Gets the number of parameters in the "v" direction.

## Methods

- [Dispose](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/dispose.md): Actively reclaims unmanaged resources that this instance uses.
- [PointAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/pointat.md): Gets the interpolation point at the u,v parameter location.
- [SetPointAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/setpointat.md): Sets the interpolation point at the u,v parameter location.
- [SetTwistAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/settwistat.md): Set the twist direction (mixed second partial derivative) to interpolate at the u,v parameter location.
- [SetUParameterAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/setuparameterat.md): Sets the "u" parameter at an index. These parameters are strictly increasing.
- [SetUTangentAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/setutangentat.md): Set the "u" tangent direction (actually first derivative) to interpolate at the u,v parameter location.
- [SetVParameterAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/setvparameterat.md): Sets the "v" parameter at an index. These parameters are strictly increasing.
- [SetVTangentAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/setvtangentat.md): Set the "v" tangent direction (actually first derivative) to interpolate at the u,v parameter location.
- [ToNurbsSurface](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/tonurbssurface.md): Constructs a NURBS surface satisfying the Hermite interpolation conditions.
- [TwistAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/twistat.md): Get the twist direction (mixed second partial derivative) to interpolate at the u,v parameter location.
- [UParameterAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/uparameterat.md): Gets the "u" parameter at an index. These parameters are strictly increasing.
- [UTangentAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/utangentat.md): Get the "u" tangent direction (actually first derivative) to interpolate at the u,v parameter location.
- [VParameterAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/vparameterat.md): Gets the "v" parameter at an index. These parameters are strictly increasing.
- [VTangentAt](https://developer.rhino3d.com/api/rhinocommon/type/rhino.geometry.hermitesurface/vtangentat.md): Get the "v" tangent direction (actually first derivative) to interpolate at the u,v parameter location.