The surface chart can be an XYZ plot such as the one shown in this figure.
Each point in an XYZ series has three data values: x, y, and z. Each point is visualized as a point on a surface.
An XYZ surface series can be assigned a fill effect for the surface. Assigning null for the fill effect indicates that the property is unset.
For more information on the surface series object in the API, refer to the XYZSurfaceSeries class.