Crs.NearestPointOnLine3D Methods
Returns the point on the given line that is nearest the given point.
Overload List
| Name | Description | |
|---|---|---|
 Public method | NearestPointOnLine3D(PointCollection line, LineType lineType, System.Boolean lineClosed, Point point, out System.Int32 nearestSegmentIndex, out System.Double nearestSegmentFraction) | Returns the point on the given line that is nearest the given point. |
| Public method | NearestPointOnLine3D(IEnumerable< Point > line, LineType lineType, System.Boolean lineClosed, Point point, System.Int32 nearestSegmentIndex, System.Double nearestSegmentFraction) | Returns the point of the given line that is nearest the given point. |
NearestPointOnLine3D(PointCollection line, LineType lineType, System.Boolean lineClosed, Point point, out System.Int32 nearestSegmentIndex, out System.Double nearestSegmentFraction)
Returns the point on the given line that is nearest the given point.Syntax
public Point NearestPointOnLine3D (
PointCollection line,
LineType lineType,
System.Boolean lineClosed,
Point point,
out System.Int32 nearestSegmentIndex,
out System.Double nearestSegmentFraction
)Parameters
A given line as a collection of points.
The line type: either great circle, rhumb line or straight 3D.
Whether there is a line segment from the last point back to the first.
A given point.
Returns the index of the segment containing the nearest point.
Returns the fraction of the position of the nearest point along the nearest segment.
Return Value
The point on the given line that is nearest the given point.
Remarks
The method returns the point on the given line that is nearest the given point, and also the index of the nearest line segment, and the fraction of the position of the nearest point along the nearest segment.
The line may contain any number of points, and its segments may be rhumb lines, great-circle arcs, or straight in 3D space, although the line type GreatCircleApprox is not supported. Regardless of the line type, "nearest" refers to the straight distance in 3D space.
All z coordinates are assumed to represent meters above sea level.
For rhumb lines and great-circle arcs, it is assumed that altitude varies linearly with horizontal surface distance (at sea level) along each segment.
Accuracy
If the Projection is a NonGeoreferencedProjection, then the computation is done assuming the Crs describes a 3D Cartesian space. The accuracy is good within this geometry, but the coordinate transformation to the real world is unknown, so the real-world accuracy is also unknown.
Otherwise we have a georeferenced CRS, and the Straight3D line type should give sub-centimeter accuracy. The GreatCircle and RhumbLine line types should give sub-meter accuracy, although it may be worse if some line node altitudes are very high, say higher than 50 000 m.
NearestPointOnLine3D(IEnumerable< Point > line, LineType lineType, System.Boolean lineClosed, Point point, System.Int32 nearestSegmentIndex, System.Double nearestSegmentFraction)
Returns the point of the given line that is nearest the given point.Syntax
public Point NearestPointOnLine3D (
IEnumerable< Point > line,
LineType lineType,
System.Boolean lineClosed,
Point point,
System.Int32 nearestSegmentIndex,
System.Double nearestSegmentFraction
)Parameters
A given line as a collection of points.
The line type: either great circle, rhumb line or straight 3D.
Whether there is a line segment from the last point back to the first.
A given point.
The calculated index of the segment containing the nearest point.
The calculated fraction of the position of the nearest point along the nearest segment.
Return Value
The point on the given line that is nearest the given point.
Remarks
The method returns the point on the given line that is nearest the given point, and also the index of the nearest line segment, and the fraction of the position of the nearest point along the nearest segment.
The line may contain any number of points, and its segments may be rhumb lines, great-circle arcs, or straight in 3D space, although the line type GreatCircleApprox is not supported. Regardless of the line type, "nearest" refers to the straight distance in 3D space.
All z coordinates are assumed to represent meters above sea level.
For rhumb lines and great-circle arcs, it is assumed that altitude varies linearly with horizontal surface distance (at sea level) along each segment.
Accuracy
If the Projection is a NonGeoreferencedProjection, then the computation is done assuming the Crs describes a 3D Cartesian space. The accuracy is good within this geometry, but the coordinate transformation to the real world is unknown, so the real-world accuracy is also unknown.
Otherwise we have a georeferenced CRS, and the Straight3D line type should give sub-centimeter accuracy. The GreatCircle and RhumbLine line types should give sub-meter accuracy, although it may be worse if some line node altitudes are very high, say higher than 50 000 m.
Platforms
Windows, Linux, Android