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EllipsoidTangentPlane

A two-dimensional east-north plane tangent to the WGS84 ellipsoid. It converts WGS84 Cartesian positions into local coordinates near a point on the ellipsoid.

Usage​

import {Ellipsoid, EllipsoidTangentPlane} from '@math.gl/geospatial';

const origin = Ellipsoid.WGS84.cartographicToCartesian([-122.4, 37.8, 0]);
const tangentPlane = new EllipsoidTangentPlane(origin);
const position = Ellipsoid.WGS84.cartographicToCartesian([-122.399, 37.801, 20]);
const localPosition = tangentPlane.projectPointToNearestOnPlane(position);

The returned Vector2 is expressed in meters. Its x component points east and its y component points north.

Fields​

origin : Vector3​

The Cartesian point where the plane touches the WGS84 ellipsoid. An input point away from the surface is projected onto the ellipsoid when the plane is constructed.

plane : Plane​

The tangent plane in Hessian normal form.

xAxis : Vector3​

The unit vector pointing east from origin.

yAxis : Vector3​

The unit vector pointing north from origin.

zAxis : Vector3​

The outward-facing unit normal of the ellipsoid at origin.

Methods​

constructor(origin : Number[3])​

Creates a tangent plane from a nonzero WGS84 Cartesian point.

projectPointToNearestOnPlane(cartesian : Number[3], result? : Vector2) : Vector2​

Projects a WGS84 Cartesian point orthogonally onto the plane and expresses it in local east-north coordinates.

  • cartesian - The WGS84 Cartesian point to project.
  • result - Optional Vector2 in which to store the result.

Returns the supplied result or a new Vector2.