About Creating a Profile by Best Fit

Create a profile that follows the most logical path through a series of surface profiles, feature lines, COGO points, or AutoCAD 3D polylines, points, or blocks.

This tool uses a complex algorithm that you can adjust to obtain the desired results based on the type and the accuracy of the source data.

For example, when one uses COGO points as source data, the specified points are projected onto the alignment, and then sorted by station. The station on the alignment and the elevation of each point is determined; if a second path of points is specified, then the offset distance from the alignment also is determined.

Next, the algorithm calculates tangents (2) based on the sequence of the points and the specified Maximum Radius For Curve Detection setting. When a sequence of points has a radius that is greater than this setting, the points form a tangent. The apparent intersection of the tangents (3) are the points of intersection for the profile tangents. The algorithm calculates arcs or parabolas (1) by approximating the curvature by linking the sample points together with linear segments. To increase the accuracy when using either feature lines or 3D polylines, intermediate sample points may be either weeded from the original input data or created between each pair of sample points.