### Spline Path area

Spline Path area

The Spline Path area contains several options that you can use to create a spline path to which your scan's theoretical path will be fitted.

This area does not exist for Perimeter, Rotary, UV, or Grid scans.

Using this area, you can determine whether or not the spline path will form an open or a closed path, whether the path's calculation is interpolated or approximated, whether or not the points have a weight, and whether the spacing of the points is controlled by a defined density or a certain number of hits.

When you finally calculate the spline path, the existing Theoretical Path list gets replaced with any filtered points. These points become the basis of the scan.

This area contains these items:

Item | Description
Curve list | This list contains two options: Open and Closed. An open curve passes through the start, control, and end points and then stops. A closed curve does the same but when the curve passes through the end point, it also returns to the start point.
Calculation list | This list contains two options: Approximate and Interpolated. It determines whether the spline path passes through points in the spline (interpolated) or simply approaches the points (approximate). Interpolated results in sharper curves and approximate results in smoother curves.
Weight list | This list contains two options: Yes and No. What you select determines whether or not PC-DMIS should give the points a weight when constructing the spline path. If set to yes, then PC-DMIS gives them a weight according to how close they are to other points on the curve. The further they are from other points the greater weight they have in the fitting process.
Spacing list | This list contains two options: Density and Hits.

- If you select Density, PC-DMIS will create the spline path points at a given increment defined by the value in the Density box.

- If you select Number of Hits, PC-DMIS will create the spline path points using and spacing the number of hits you specify in the Density box.

Density box | This controls the density or number of hits along the scan's path.

- If you selected Density from Spacing list above, this box holds the increment value that controls the density of hits. The smaller the increment the greater the density.

- If you selected Number of Hits from the Spacing list above, this box holds the number of hits to space along the theoretical pathway. If you typed "50", for example, PC-DMIS would attempt to fit all fifty points along the scan path.

Calculate button | This button calculates the spline and fits the theoretical data points to the spline, usually filtering out several hits. This button only becomes enabled if you have at least five hits in the Theoretical Path list.