# BoundingSphere

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.

### Members

#### staticBoundingSphere.packedLength :Number

The number of elements used to pack the object into an array.

#### center :Cartesian3

The center point of the sphere.
Default Value: `Cartesian3.ZERO`

Default Value: `0.0`

### Methods

#### staticBoundingSphere.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)

#### staticBoundingSphere.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.

#### staticBoundingSphere.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 estimated distance squared from the bounding sphere to the point.
##### 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);
});``````

#### staticBoundingSphere.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.

#### staticBoundingSphere.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.

#### staticBoundingSphere.fromBoundingSpheres(boundingSpheres, result) → BoundingSphere

Computes a tight-fitting bounding sphere enclosing the provided array of bounding spheres.
Name Type Description
`boundingSpheres` Array.<BoundingSphere> 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.

#### staticBoundingSphere.fromCornerPoints(corner, oppositeCorner, result) → BoundingSphere

Computes a bounding sphere from the corner points of an axis-aligned bounding box. The sphere tighly and fully encompases 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
var sphere = Cesium.BoundingSphere.fromCornerPoints(new Cesium.Cartesian3(-0.5, -0.5, -0.5), new Cesium.Cartesian3(0.5, 0.5, 0.5));``````

#### staticBoundingSphere.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:
``var boundingSphere = Cesium.BoundingSphere.fromEllipsoid(ellipsoid);``

#### staticBoundingSphere.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> 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.

#### staticBoundingSphere.fromRectangle2D(rectangle, projection, result) → BoundingSphere

Computes a bounding sphere from an rectangle projected in 2D.
Name Type Default Description
`rectangle` Rectangle 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.

#### staticBoundingSphere.fromRectangle3D(rectangle, ellipsoid, surfaceHeight, result) → BoundingSphere

Computes a bounding sphere from an 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 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.

#### staticBoundingSphere.fromRectangleWithHeights2D(rectangle, projection, minimumHeight, maximumHeight, result) → BoundingSphere

Computes a bounding sphere from an 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 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.

#### staticBoundingSphere.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> 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.
var center = new Cesium.Cartesian3(1.0, 2.0, 3.0);
var 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];
var sphere = Cesium.BoundingSphere.fromVertices(points, center, 5);``````

#### staticBoundingSphere.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.

#### staticBoundingSphere.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`.

#### staticBoundingSphere.pack(value, array, startingIndex)

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.

#### staticBoundingSphere.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.

#### staticBoundingSphere.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.

#### staticBoundingSphere.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:
``````var modelMatrix = Cesium.Transforms.eastNorthUpToFixedFrame(positionOnEllipsoid);
var boundingSphere = new Cesium.BoundingSphere();
var newBoundingSphere = Cesium.BoundingSphere.transformWithoutScale(boundingSphere, modelMatrix);``````

#### staticBoundingSphere.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.

#### staticBoundingSphere.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.

#### clone(result) → BoundingSphere

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.

#### intersectPlane(plane) → Intersect

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`.