Specify Surface Modeling

The Specify Surface Modeling toolbar button is used to refine the 3D rendering.

Interpolation

The Interpolate algorithm uses a triangular interpolant to generate a surface through each point. There is no smoothing.

The Fast Smooth algorithm uses a Loess 3D nearest neighbor smoothing algorithm, and the same triangular interpolant is passed through the smoothed points.

Surface Type

The C0 Continuous Surface generates a continuous but not smooth surface through the points. C0 means zero times continuously differentiable; the surface does not have continuous dx/dz and dy/dz derivatives.

The C1 Continuous Surface generates a surface through the points. C1 means one time continuously differentiable; the surface has continuous but not smooth dx/dz and dy/dz derivatives.

Nearest Neighbor Smoothing

You can choose Model Order 1 (Linear), 2 (Quadratic), or 3 (Cubic). The higher order models will offer a higher accuracy but require more points for an effective fit in the Loess smoothing algorithm.

The Neighbor Count will range from the minimum permissible to the maximum data count. For a higher order fit, you may need to specify all of the points if the amount of data is small.

If you are smoothing the data you will probably wish to use the C1 interpolant. In general, you will want to use the lowest level of smoothing that gives you a smooth surface free of artifacts. You should use this procedure extensively to optimize the smoothing for any surface for which you wish to infer trends.