Functions for computing the intersection between geometries such as rays, planes, triangles, and ellipsoids.
Methods
static Cesium.IntersectionTests.grazingAltitudeLocation(ray, ellipsoid) → Cartesian3
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 Cesium.IntersectionTests.lineSegmentPlane(endPoint0, endPoint1, plane, result) → Cartesian3
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 = Cesium.Cartesian3.fromDegrees(-75.59777, 40.03883);
const normal = ellipsoid.geodeticSurfaceNormal(origin);
const plane = Cesium.Plane.fromPointNormal(origin, normal);
const p0 = new Cesium.Cartesian3(...);
const p1 = new Cesium.Cartesian3(...);
// find the intersection of the line segment from p0 to p1 and the tangent plane at origin.
const intersection = Cesium.IntersectionTests.lineSegmentPlane(p0, p1, plane);
static Cesium.IntersectionTests.lineSegmentSphere(p0, p1, sphere, result) → Interval
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 Cesium.IntersectionTests.lineSegmentTriangle(v0, v1, p0, p1, p2, cullBackFaces, result) → Cartesian3
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 Cesium.IntersectionTests.rayEllipsoid(ray, ellipsoid) → Interval
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 Cesium.IntersectionTests.rayPlane(ray, plane, result) → Cartesian3
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 Cesium.IntersectionTests.raySphere(ray, sphere, result) → Interval
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 Cesium.IntersectionTests.rayTriangle(ray, p0, p1, p2, cullBackFaces, result) → Cartesian3
Computes the intersection of a ray and a triangle as a Cartesian3 coordinate.
Implements {@link https://cadxfem.org/inf/Fast%20MinimumStorage%20RayTriangle%20Intersection.pdf|
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.
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 {@link https://cadxfem.org/inf/Fast%20MinimumStorage%20RayTriangle%20Intersection.pdf|
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.
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 = Cesium.Cartesian3.fromDegrees(-75.59777, 40.03883);
const normal = ellipsoid.geodeticSurfaceNormal(origin);
const plane = Cesium.Plane.fromPointNormal(origin, normal);
const p0 = new Cesium.Cartesian3(...);
const p1 = new Cesium.Cartesian3(...);
const p2 = new Cesium.Cartesian3(...);
// convert the triangle composed of points (p0, p1, p2) to three triangles that don't cross the plane
const triangles = Cesium.IntersectionTests.trianglePlaneIntersection(p0, p1, p2, plane);