Plane

A plane in Hessian Normal Form defined by ax + by + cz + d = 0 where [a, b, c] is the plane's normal, d is the signed distance to the plane (from the origin along the normal), and [x, y, z] is any point on the plane.

Usage

Create the plane x=0

import {Plane} from '@math.gl/culling';
const plane = new Plane([1, 0, 0], 0.0);

Create a tangent plane for a cartographic coordinate

import {Plane} from '@math.gl/culling';
import {Ellipsoid} from '@math.gl/geospatial';
const point = [-72.0, 40.0, 0];
const normal = Ellipsoid.WGS84.geodeticSurfaceNormal([-72.0, 40.0]);
const tangentPlane = new Plane().fromPointNormal(point, normal);

Fields

normal : Vector3

The plane's normal.

distance : Number

The shortest distance from the origin to the plane. The sign of distance determines which side of the plane the origin is on. If distance is positive, the origin is in the half-space in the direction of the normal; if negative, the origin is in the half-space opposite to the normal; if zero, the plane passes through the origin.

Methods

constructor(normal : Number[3], distance : Number)

  • Vector3 normal The plane's normal (normalized).
  • Number distance The shortest distance from the origin to the plane. The sign of distance determines which side of the plane the origin is on. If distance is positive, the origin is in the half-space in the direction of the normal; if negative, the origin is in the half-space opposite to the normal; if zero, the plane passes through the origin.

Throws

  • Normal must be normalized

fromPointNormal(point : Number[3], normal : Number[3]) : Plane

Creates a plane from a normal and a point on the plane.

  • Vector3 point The point on the plane.
  • Vector3 normal The plane's normal (normalized).
  • Plane [result] The object onto which to store the result.

Throws

  • Normal must be normalized

Plane.fromCoefficients(coefficients : Number[4]) : Plane

Creates a plane from the general equation

  • coefficients The plane coefficients (normalized).

Throws

  • Normal must be normalized

clone() : Plane

Duplicates a Plane instance.

Returns

  • A new Plane instance with the same values

equals(right : Plane) : Boolean

Compares the provided Planes by normal and distance and returns true if they are equal, false otherwise.

  • right The second plane.

Returns

  • true if left and right are equal, false otherwise.

getPointDistance(point : Number[3]) : Number

Computes the signed shortest distance of a point to a plane. The sign of the distance determines which side of the plane the point is on. If the distance is positive, the point is in the half-space in the direction of the normal; if negative, the point is in the half-space opposite to the normal; if zero, the plane passes through the point.

  • point The point.

Returns

  • Number The signed shortest distance of the point to the plane.

projectPointOntoPlane(point : Number[3], result : Number[3]]) : Number[3]

Projects a point onto the plane.

  • point The point to project onto the plane
  • result The result point. If undefined, a new Array will be created.

Returns

  • The modified result parameter or a new Vector3 instance if one was not provided.

transform(transform : Number[16]) : Plane

Transforms the plane by the given transformation matrix.

  • Matrix4 transform The transformation matrix.
  • Plane [result] The object into which to store the result.

Returns

  • Plane The plane transformed by the given transformation matrix.

Attribution

This class was ported from Cesium under the Apache 2 License.