Class SpatialConcaveHull
- Namespace
- YndigoBlue.Velocity.Functions
- Assembly
- YndigoBlue.Velocity.dll
Represents the ST_ConcaveHull spatial analysis function that computes a concave hull (alpha shape) around a geometry.
public class SpatialConcaveHull : Function, IElement, ICheckItem, IDefaultItem, IFilterItem- Inheritance
-
SpatialConcaveHull
- Implements
Remarks
Warning
Spatial functions are not available in the Community Edition of Velocity. They require the Full Edition.
The ST_ConcaveHull function returns a polygon representing a concave hull that encloses a geometry, providing a tighter fit than a convex hull by allowing concave edges. The percentConvex parameter (0.0 to 1.0) controls the level of concavity, where 0.0 produces the most concave result possible and 1.0 approaches a convex hull. This is useful for creating boundary polygons that better follow the shape of point clusters or complex geometries. For Geometry types in planar coordinate systems, helpful for spatial clustering, point cloud analysis, or generating more accurate boundaries than convex hulls.
Return Type: Polygon geometry that encloses the input geometry.
| percentConvex Value | Result Characteristics |
|---|---|
| 0.0 | Most concave hull possible - tightest fit to points |
| 0.5 | Moderate concavity - balanced fit |
| 1.0 | Equivalent to ST_ConvexHull - no concave edges |
Constructors
- SpatialConcaveHull(Geometry, float)
Initializes a new instance of ST_ConcaveHull with a geometry literal and concavity parameter.
- SpatialConcaveHull(Column, float)
Initializes a new instance of ST_ConcaveHull with a geometry column and concavity parameter.
- SpatialConcaveHull(Function, float)
Initializes a new instance of ST_ConcaveHull for a function result.
- SpatialConcaveHull(Geography, float)
Initializes a new instance of ST_ConcaveHull with a geography literal and concavity parameter.