The surface chart can be an XYZ plot such as the one shown in this figure.
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.
Each point in a XYZ series has three data values: x, y, and z. Each point is visualized as a point on a surface.
For more information on the surface series object in the API, refer to the XYZSurfaceSeries class.