IntersectionTests

Core/IntersectionTests.js 13
Functions for computing the intersection between geometries such as rays, planes, triangles, and ellipsoids.

Methods

static Freedo.IntersectionTests.grazingAltitudeLocation(ray, ellipsoid) → Cartesian3
Core/IntersectionTests.js 662

Provides the point along the ray which is nearest to the ellipsoid.
Name Type Description
ray Ray The ray.
ellipsoid Ellipsoid The ellipsoid.
Returns:
The nearest planetodetic point on the ray.

static Freedo.IntersectionTests.intersetRectangleWithConstraintRegion(rectangle, constraintRegions) → Number
Core/IntersectionTests.js 1109

判断矩形范围是否与限制区相交
Name Type Default Description
rectangle Rectangle 矩形范围.
constraintRegions Array.<Object> 限制区数组.
constraintRegions[i].constraintRegion Array.<Array.<Number>> 限制区，[[longitude0, latitude0], [longitude1, latitude1], [longitude2, latitude2], [longitude3, latitude3]...].
constraintRegions[i].height Number 0.0 optional 限制区拉平的高度.
Returns:
返回与rectangle相交的constraintRegions索引，或者-1表示不相交.
Example:
var constraintRegions = [{
constraintRegion: [
  [FreedoMath.toRadians(115.777349), FreedoMath.toRadians(38.947522)],
  [FreedoMath.toRadians(115.779750), FreedoMath.toRadians(38.947522)],
  [FreedoMath.toRadians(115.778750), FreedoMath.toRadians(38.947922)],
  [FreedoMath.toRadians(115.779750), FreedoMath.toRadians(38.948693)],
  [FreedoMath.toRadians(115.777349), FreedoMath.toRadians(38.948693)]
 ]
}, {
constraintRegion: [
  [FreedoMath.toRadians(115.779523), FreedoMath.toRadians(38.945631)],
  [FreedoMath.toRadians(115.781864), FreedoMath.toRadians(38.945631)],
  [FreedoMath.toRadians(115.781864), FreedoMath.toRadians(38.946725)],
  [FreedoMath.toRadians(115.779523), FreedoMath.toRadians(38.946725)]
 ]
}];
var rectangle = new Rectangle(west, south, east, north);
var intersetIndex = IntersectionTests.intersetRectangleWithConstraintRegion(rectangle, constraintRegions);

static Freedo.IntersectionTests.isCartographicInConstraintRegion(cartographic, mostPossibleIndex, constraintRegions) → Number
Core/IntersectionTests.js 1202

判断经纬度点是否在限制区内
Name Type Default Description
cartographic Cartographic 待判断的经纬度点.
mostPossibleIndex Number 最可能与哪个限制区相交.
constraintRegions Array.<Object> 限制区数组.
constraintRegions[i].constraintRegion Array.<Array.<Number>> 限制区，[[longitude0, latitude0], [longitude1, latitude1], [longitude2, latitude2], [longitude3, latitude3]...].
constraintRegions[i].height Number 0.0 optional 限制区拉平的高度.
Returns:
返回与cartographic相交的constraintRegions索引，或者-1表示不相交.
Example:
var constraintRegions = [{
constraintRegion: [
  [FreedoMath.toRadians(115.777349), FreedoMath.toRadians(38.947522)],
  [FreedoMath.toRadians(115.779750), FreedoMath.toRadians(38.947522)],
  [FreedoMath.toRadians(115.778750), FreedoMath.toRadians(38.947922)],
  [FreedoMath.toRadians(115.779750), FreedoMath.toRadians(38.948693)],
  [FreedoMath.toRadians(115.777349), FreedoMath.toRadians(38.948693)]
 ]
}, {
constraintRegion: [
  [FreedoMath.toRadians(115.779523), FreedoMath.toRadians(38.945631)],
  [FreedoMath.toRadians(115.781864), FreedoMath.toRadians(38.945631)],
  [FreedoMath.toRadians(115.781864), FreedoMath.toRadians(38.946725)],
  [FreedoMath.toRadians(115.779523), FreedoMath.toRadians(38.946725)]
 ]
}];
var cartographic = new Cartographic(FreedoMath.toRadians(115.78), FreedoMath.toRadians(38.946));
var intersetIndex = IntersectionTests.isCartographicInConstraintRegion(cartographic, -1, constraintRegions);

static Freedo.IntersectionTests.lineSegmentPlane(endPoint0, endPoint1, plane, result) → Cartesian3
Core/IntersectionTests.js 815

Computes the intersection of a line segment and a plane.
Name Type Description
endPoint0 Cartesian3 An end point of the line segment.
endPoint1 Cartesian3 The other end point of the line segment.
plane Plane The plane.
result Cartesian3 optional The object onto which to store the result.
Returns:
The intersection point or undefined if there is no intersection.
Example:
const origin = Freedo.Cartesian3.fromDegrees(-75.59777, 40.03883);
const normal = ellipsoid.geodeticSurfaceNormal(origin);
const plane = Freedo.Plane.fromPointNormal(origin, normal);

const p0 = new Freedo.Cartesian3(...);
const p1 = new Freedo.Cartesian3(...);

// find the intersection of the line segment from p0 to p1 and the tangent plane at origin.
const intersection = Freedo.IntersectionTests.lineSegmentPlane(p0, p1, plane);

static Freedo.IntersectionTests.lineSegmentSphere(p0, p1, sphere, result) → Interval
Core/IntersectionTests.js 381

Computes the intersection points of a line segment with a sphere.
Name Type Description
p0 Cartesian3 An end point of the line segment.
p1 Cartesian3 The other end point of the line segment.
sphere BoundingSphere The sphere.
result Interval optional The result onto which to store the result.
Returns:
The interval containing scalar points along the ray or undefined if there are no intersections.

static Freedo.IntersectionTests.lineSegmentTriangle(v0, v1, p0, p1, p2, cullBackFaces, result) → Cartesian3
Core/IntersectionTests.js 228

Computes the intersection of a line segment and a triangle.
Name Type Default Description
v0 Cartesian3 The an end point of the line segment.
v1 Cartesian3 The other end point of the line segment.
p0 Cartesian3 The first vertex of the triangle.
p1 Cartesian3 The second vertex of the triangle.
p2 Cartesian3 The third vertex of the triangle.
cullBackFaces Boolean false optional If true, will only compute an intersection with the front face of the triangle and return undefined for intersections with the back face.
result Cartesian3 optional The Cartesian3 onto which to store the result.
Returns:
The intersection point or undefined if there is no intersections.

static Freedo.IntersectionTests.rayEllipsoid(ray, ellipsoid) → Interval
Core/IntersectionTests.js 421

Computes the intersection points of a ray with an ellipsoid.
Name Type Description
ray Ray The ray.
ellipsoid Ellipsoid The ellipsoid.
Returns:
The interval containing scalar points along the ray or undefined if there are no intersections.

static Freedo.IntersectionTests.rayPlane(ray, plane, result) → Cartesian3
Core/IntersectionTests.js 28

Computes the intersection of a ray and a plane.
Name Type Description
ray Ray The ray.
plane Plane The plane.
result Cartesian3 optional The object onto which to store the result.
Returns:
The intersection point or undefined if there is no intersections.

static Freedo.IntersectionTests.raySphere(ray, sphere, result) → Interval
Core/IntersectionTests.js 350

Computes the intersection points of a ray with a sphere.
Name Type Description
ray Ray The ray.
sphere BoundingSphere The sphere.
result Interval optional The result onto which to store the result.
Returns:
The interval containing scalar points along the ray or undefined if there are no intersections.

static Freedo.IntersectionTests.rayTriangle(ray, p0, p1, p2, cullBackFaces, result) → Cartesian3
Core/IntersectionTests.js 185

Computes the intersection of a ray and a triangle as a Cartesian3 coordinate. Implements Fast Minimum Storage Ray/Triangle Intersection by Tomas Moller and Ben Trumbore.
Name Type Default Description
ray Ray The ray.
p0 Cartesian3 The first vertex of the triangle.
p1 Cartesian3 The second vertex of the triangle.
p2 Cartesian3 The third vertex of the triangle.
cullBackFaces Boolean false optional If true, will only compute an intersection with the front face of the triangle and return undefined for intersections with the back face.
result Cartesian3 optional The Cartesian3 onto which to store the result.
Returns:
The intersection point or undefined if there is no intersections.

static Freedo.IntersectionTests.rayTriangleParametric(ray, p0, p1, p2, cullBackFaces) → Number
Core/IntersectionTests.js 84

Computes the intersection of a ray and a triangle as a parametric distance along the input ray. The result is negative when the triangle is behind the ray. Implements Fast Minimum Storage Ray/Triangle Intersection by Tomas Moller and Ben Trumbore.
Name Type Default Description
ray Ray The ray.
p0 Cartesian3 The first vertex of the triangle.
p1 Cartesian3 The second vertex of the triangle.
p2 Cartesian3 The third vertex of the triangle.
cullBackFaces Boolean false optional If true, will only compute an intersection with the front face of the triangle and return undefined for intersections with the back face.
Returns:
The intersection as a parametric distance along the ray, or undefined if there is no intersection.

static Freedo.IntersectionTests.trianglePlaneIntersection(p0, p1, p2, plane) → Object
Core/IntersectionTests.js 885

Computes the intersection of a triangle and a plane
Name Type Description
p0 Cartesian3 First point of the triangle
p1 Cartesian3 Second point of the triangle
p2 Cartesian3 Third point of the triangle
plane Plane Intersection plane
Returns:
An object with properties positions and indices, which are arrays that represent three triangles that do not cross the plane. (Undefined if no intersection exists)
Example:
const origin = Freedo.Cartesian3.fromDegrees(-75.59777, 40.03883);
const normal = ellipsoid.geodeticSurfaceNormal(origin);
const plane = Freedo.Plane.fromPointNormal(origin, normal);

const p0 = new Freedo.Cartesian3(...);
const p1 = new Freedo.Cartesian3(...);
const p2 = new Freedo.Cartesian3(...);

// convert the triangle composed of points (p0, p1, p2) to three triangles that don't cross the plane
const triangles = Freedo.IntersectionTests.trianglePlaneIntersection(p0, p1, p2, plane);