English | 简体中文

BoundingSphere

new Cesium.BoundingSphere(center, radius)

A bounding sphere with a center and a radius.
Name Type Default Description
center Cartesian3 Cartesian3.ZERO optional The center of the bounding sphere.
radius number 0.0 optional The radius of the bounding sphere.
See:

Members

static Cesium.BoundingSphere.packedLength : number

The number of elements used to pack the object into an array.
The center point of the sphere.
Default Value: Cartesian3.ZERO
The radius of the sphere.
Default Value: 0.0

Methods

static Cesium.BoundingSphere.clone(sphere, result)BoundingSphere

Duplicates a BoundingSphere instance.
Name Type Description
sphere BoundingSphere The bounding sphere to duplicate.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided. (Returns undefined if sphere is undefined)

static Cesium.BoundingSphere.computePlaneDistances(sphere, position, direction, result)Interval

The distances calculated by the vector from the center of the bounding sphere to position projected onto direction plus/minus the radius of the bounding sphere.
If you imagine the infinite number of planes with normal direction, this computes the smallest distance to the closest and farthest planes from position that intersect the bounding sphere.
Name Type Description
sphere BoundingSphere The bounding sphere to calculate the distance to.
position Cartesian3 The position to calculate the distance from.
direction Cartesian3 The direction from position.
result Interval optional A Interval to store the nearest and farthest distances.
Returns:
The nearest and farthest distances on the bounding sphere from position in direction.

static Cesium.BoundingSphere.distanceSquaredTo(sphere, cartesian)number

Computes the estimated distance squared from the closest point on a bounding sphere to a point.
Name Type Description
sphere BoundingSphere The sphere.
cartesian Cartesian3 The point
Returns:
The distance squared from the bounding sphere to the point. Returns 0 if the point is inside the sphere.
Example:
// Sort bounding spheres from back to front
spheres.sort(function(a, b) {
    return Cesium.BoundingSphere.distanceSquaredTo(b, camera.positionWC) - Cesium.BoundingSphere.distanceSquaredTo(a, camera.positionWC);
});

static Cesium.BoundingSphere.equals(left, right)boolean

Compares the provided BoundingSphere componentwise and returns true if they are equal, false otherwise.
Name Type Description
left BoundingSphere optional The first BoundingSphere.
right BoundingSphere optional The second BoundingSphere.
Returns:
true if left and right are equal, false otherwise.

static Cesium.BoundingSphere.expand(sphere, point, result)BoundingSphere

Computes a bounding sphere by enlarging the provided sphere to contain the provided point.
Name Type Description
sphere BoundingSphere A sphere to expand.
point Cartesian3 A point to enclose in a bounding sphere.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

static Cesium.BoundingSphere.fromBoundingSpheres(boundingSpheres, result)BoundingSphere

Computes a tight-fitting bounding sphere enclosing the provided array of bounding spheres.
Name Type Description
boundingSpheres Array.<BoundingSphere> optional The array of bounding spheres.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

static Cesium.BoundingSphere.fromCornerPoints(corner, oppositeCorner, result)BoundingSphere

Computes a bounding sphere from the corner points of an axis-aligned bounding box. The sphere tightly and fully encompasses the box.
Name Type Description
corner Cartesian3 optional The minimum height over the rectangle.
oppositeCorner Cartesian3 optional The maximum height over the rectangle.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.
Example:
// Create a bounding sphere around the unit cube
const sphere = Cesium.BoundingSphere.fromCornerPoints(new Cesium.Cartesian3(-0.5, -0.5, -0.5), new Cesium.Cartesian3(0.5, 0.5, 0.5));

static Cesium.BoundingSphere.fromEllipsoid(ellipsoid, result)BoundingSphere

Creates a bounding sphere encompassing an ellipsoid.
Name Type Description
ellipsoid Ellipsoid The ellipsoid around which to create a bounding sphere.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.
Example:
const boundingSphere = Cesium.BoundingSphere.fromEllipsoid(ellipsoid);

static Cesium.BoundingSphere.fromEncodedCartesianVertices(positionsHigh, positionsLow, result)BoundingSphere

Computes a tight-fitting bounding sphere enclosing a list of EncodedCartesian3s, where the points are stored in parallel flat arrays in X, Y, Z, order. The bounding sphere is computed by running two algorithms, a naive algorithm and Ritter's algorithm. The smaller of the two spheres is used to ensure a tight fit.
Name Type Description
positionsHigh Array.<number> optional An array of high bits of the encoded cartesians that the bounding sphere will enclose. Each point is formed from three elements in the array in the order X, Y, Z.
positionsLow Array.<number> optional An array of low bits of the encoded cartesians that the bounding sphere will enclose. Each point is formed from three elements in the array in the order X, Y, Z.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if one was not provided.
See:

static Cesium.BoundingSphere.fromOrientedBoundingBox(orientedBoundingBox, result)BoundingSphere

Computes a tight-fitting bounding sphere enclosing the provided oriented bounding box.
Name Type Description
orientedBoundingBox OrientedBoundingBox The oriented bounding box.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

static Cesium.BoundingSphere.fromPoints(positions, result)BoundingSphere

Computes a tight-fitting bounding sphere enclosing a list of 3D Cartesian points. The bounding sphere is computed by running two algorithms, a naive algorithm and Ritter's algorithm. The smaller of the two spheres is used to ensure a tight fit.
Name Type Description
positions Array.<Cartesian3> optional An array of points that the bounding sphere will enclose. Each point must have x, y, and z properties.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if one was not provided.
See:

static Cesium.BoundingSphere.fromRectangle2D(rectangle, projection, result)BoundingSphere

Computes a bounding sphere from a rectangle projected in 2D.
Name Type Default Description
rectangle Rectangle optional The rectangle around which to create a bounding sphere.
projection object GeographicProjection optional The projection used to project the rectangle into 2D.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

static Cesium.BoundingSphere.fromRectangle3D(rectangle, ellipsoid, surfaceHeight, result)BoundingSphere

Computes a bounding sphere from a rectangle in 3D. The bounding sphere is created using a subsample of points on the ellipsoid and contained in the rectangle. It may not be accurate for all rectangles on all types of ellipsoids.
Name Type Default Description
rectangle Rectangle optional The valid rectangle used to create a bounding sphere.
ellipsoid Ellipsoid Ellipsoid.WGS84 optional The ellipsoid used to determine positions of the rectangle.
surfaceHeight number 0.0 optional The height above the surface of the ellipsoid.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

static Cesium.BoundingSphere.fromRectangleWithHeights2D(rectangle, projection, minimumHeight, maximumHeight, result)BoundingSphere

Computes a bounding sphere from a rectangle projected in 2D. The bounding sphere accounts for the object's minimum and maximum heights over the rectangle.
Name Type Default Description
rectangle Rectangle optional The rectangle around which to create a bounding sphere.
projection object GeographicProjection optional The projection used to project the rectangle into 2D.
minimumHeight number 0.0 optional The minimum height over the rectangle.
maximumHeight number 0.0 optional The maximum height over the rectangle.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

static Cesium.BoundingSphere.fromTransformation(transformation, result)BoundingSphere

Computes a tight-fitting bounding sphere enclosing the provided affine transformation.
Name Type Description
transformation Matrix4 The affine transformation.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

static Cesium.BoundingSphere.fromVertices(positions, center, stride, result)BoundingSphere

Computes a tight-fitting bounding sphere enclosing a list of 3D points, where the points are stored in a flat array in X, Y, Z, order. The bounding sphere is computed by running two algorithms, a naive algorithm and Ritter's algorithm. The smaller of the two spheres is used to ensure a tight fit.
Name Type Default Description
positions Array.<number> optional An array of points that the bounding sphere will enclose. Each point is formed from three elements in the array in the order X, Y, Z.
center Cartesian3 Cartesian3.ZERO optional The position to which the positions are relative, which need not be the origin of the coordinate system. This is useful when the positions are to be used for relative-to-center (RTC) rendering.
stride number 3 optional The number of array elements per vertex. It must be at least 3, but it may be higher. Regardless of the value of this parameter, the X coordinate of the first position is at array index 0, the Y coordinate is at array index 1, and the Z coordinate is at array index 2. When stride is 3, the X coordinate of the next position then begins at array index 3. If the stride is 5, however, two array elements are skipped and the next position begins at array index 5.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if one was not provided.
Example:
// Compute the bounding sphere from 3 positions, each specified relative to a center.
// In addition to the X, Y, and Z coordinates, the points array contains two additional
// elements per point which are ignored for the purpose of computing the bounding sphere.
const center = new Cesium.Cartesian3(1.0, 2.0, 3.0);
const points = [1.0, 2.0, 3.0, 0.1, 0.2,
              4.0, 5.0, 6.0, 0.1, 0.2,
              7.0, 8.0, 9.0, 0.1, 0.2];
const sphere = Cesium.BoundingSphere.fromVertices(points, center, 5);
See:

static Cesium.BoundingSphere.intersectPlane(sphere, plane)Intersect

Determines which side of a plane a sphere is located.
Name Type Description
sphere BoundingSphere The bounding sphere to test.
plane Plane The plane to test against.
Returns:
Intersect.INSIDE if the entire sphere is on the side of the plane the normal is pointing, Intersect.OUTSIDE if the entire sphere is on the opposite side, and Intersect.INTERSECTING if the sphere intersects the plane.

static Cesium.BoundingSphere.isOccluded(sphere, occluder)boolean

Determines whether or not a sphere is hidden from view by the occluder.
Name Type Description
sphere BoundingSphere The bounding sphere surrounding the occludee object.
occluder Occluder The occluder.
Returns:
true if the sphere is not visible; otherwise false.

static Cesium.BoundingSphere.pack(value, array, startingIndex)Array.<number>

Stores the provided instance into the provided array.
Name Type Default Description
value BoundingSphere The value to pack.
array Array.<number> The array to pack into.
startingIndex number 0 optional The index into the array at which to start packing the elements.
Returns:
The array that was packed into

static Cesium.BoundingSphere.projectTo2D(sphere, projection, result)BoundingSphere

Creates a bounding sphere in 2D from a bounding sphere in 3D world coordinates.
Name Type Default Description
sphere BoundingSphere The bounding sphere to transform to 2D.
projection object GeographicProjection optional The projection to 2D.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

static Cesium.BoundingSphere.transform(sphere, transform, result)BoundingSphere

Applies a 4x4 affine transformation matrix to a bounding sphere.
Name Type Description
sphere BoundingSphere The bounding sphere to apply the transformation to.
transform Matrix4 The transformation matrix to apply to the bounding sphere.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

static Cesium.BoundingSphere.transformWithoutScale(sphere, transform, result)BoundingSphere

Applies a 4x4 affine transformation matrix to a bounding sphere where there is no scale The transformation matrix is not verified to have a uniform scale of 1. This method is faster than computing the general bounding sphere transform using BoundingSphere.transform.
Name Type Description
sphere BoundingSphere The bounding sphere to apply the transformation to.
transform Matrix4 The transformation matrix to apply to the bounding sphere.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.
Example:
const modelMatrix = Cesium.Transforms.eastNorthUpToFixedFrame(positionOnEllipsoid);
const boundingSphere = new Cesium.BoundingSphere();
const newBoundingSphere = Cesium.BoundingSphere.transformWithoutScale(boundingSphere, modelMatrix);

static Cesium.BoundingSphere.union(left, right, result)BoundingSphere

Computes a bounding sphere that contains both the left and right bounding spheres.
Name Type Description
left BoundingSphere A sphere to enclose in a bounding sphere.
right BoundingSphere A sphere to enclose in a bounding sphere.
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

static Cesium.BoundingSphere.unpack(array, startingIndex, result)BoundingSphere

Retrieves an instance from a packed array.
Name Type Default Description
array Array.<number> The packed array.
startingIndex number 0 optional The starting index of the element to be unpacked.
result BoundingSphere optional The object into which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if one was not provided.
Duplicates this BoundingSphere instance.
Name Type Description
result BoundingSphere optional The object onto which to store the result.
Returns:
The modified result parameter or a new BoundingSphere instance if none was provided.

computePlaneDistances(position, direction, result)Interval

The distances calculated by the vector from the center of the bounding sphere to position projected onto direction plus/minus the radius of the bounding sphere.
If you imagine the infinite number of planes with normal direction, this computes the smallest distance to the closest and farthest planes from position that intersect the bounding sphere.
Name Type Description
position Cartesian3 The position to calculate the distance from.
direction Cartesian3 The direction from position.
result Interval optional A Interval to store the nearest and farthest distances.
Returns:
The nearest and farthest distances on the bounding sphere from position in direction.

distanceSquaredTo(cartesian)number

Computes the estimated distance squared from the closest point on a bounding sphere to a point.
Name Type Description
cartesian Cartesian3 The point
Returns:
The estimated distance squared from the bounding sphere to the point.
Example:
// Sort bounding spheres from back to front
spheres.sort(function(a, b) {
    return b.distanceSquaredTo(camera.positionWC) - a.distanceSquaredTo(camera.positionWC);
});

equals(right)boolean

Compares this BoundingSphere against the provided BoundingSphere componentwise and returns true if they are equal, false otherwise.
Name Type Description
right BoundingSphere optional The right hand side BoundingSphere.
Returns:
true if they are equal, false otherwise.
Determines which side of a plane the sphere is located.
Name Type Description
plane Plane The plane to test against.
Returns:
Intersect.INSIDE if the entire sphere is on the side of the plane the normal is pointing, Intersect.OUTSIDE if the entire sphere is on the opposite side, and Intersect.INTERSECTING if the sphere intersects the plane.

isOccluded(occluder)boolean

Determines whether or not a sphere is hidden from view by the occluder.
Name Type Description
occluder Occluder The occluder.
Returns:
true if the sphere is not visible; otherwise false.
Computes the radius of the BoundingSphere.
Returns:
The radius of the BoundingSphere.
Need help? The fastest way to get answers is from the community and team on the Cesium Forum.