Creates an instance of an OrientedBoundingBox.
An OrientedBoundingBox of some object is a closed and convex cuboid. It can provide a tighter bounding volume than
BoundingSphere
or AxisAlignedBoundingBox
in many cases.
Name | Type | Default | Description |
---|---|---|---|
center |
Cartesian3 |
Cartesian3.ZERO
|
optional The center of the box. |
halfAxes |
Matrix3 |
Matrix3.ZERO
|
optional The three orthogonal half-axes of the bounding box. Equivalently, the transformation matrix, to rotate and scale a 0x0x0 cube centered at the origin. |
Example:
// Create an OrientedBoundingBox using a transformation matrix, a position where the box will be translated, and a scale.
var center = new Cesium.Cartesian3(1.0, 0.0, 0.0);
var halfAxes = Cesium.Matrix3.fromScale(new Cesium.Cartesian3(1.0, 3.0, 2.0), new Cesium.Matrix3());
var obb = new Cesium.OrientedBoundingBox(center, halfAxes);
See:
Members
The number of elements used to pack the object into an array.
center : Cartesian3
The center of the box.
-
Default Value:
Cartesian3.ZERO
halfAxes : Matrix3
The transformation matrix, to rotate the box to the right position.
-
Default Value:
Matrix3.ZERO
Methods
staticCesium.OrientedBoundingBox.clone(box, result) → OrientedBoundingBox
Duplicates a OrientedBoundingBox instance.
Name | Type | Description |
---|---|---|
box |
OrientedBoundingBox | The bounding box to duplicate. |
result |
OrientedBoundingBox | optional The object onto which to store the result. |
Returns:
The modified result parameter or a new OrientedBoundingBox instance if none was provided. (Returns undefined if box is undefined)
staticCesium.OrientedBoundingBox.computePlaneDistances(box, position, direction, result) → Interval
The distances calculated by the vector from the center of the bounding box to position projected onto direction.
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 box.
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 box.
Name | Type | Description |
---|---|---|
box |
OrientedBoundingBox | The bounding box 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 box from position in direction.
Computes the estimated distance squared from the closest point on a bounding box to a point.
Name | Type | Description |
---|---|---|
box |
OrientedBoundingBox | The box. |
cartesian |
Cartesian3 | The point |
Returns:
The estimated distance squared from the bounding sphere to the point.
Example:
// Sort bounding boxes from back to front
boxes.sort(function(a, b) {
return Cesium.OrientedBoundingBox.distanceSquaredTo(b, camera.positionWC) - Cesium.OrientedBoundingBox.distanceSquaredTo(a, camera.positionWC);
});
Compares the provided OrientedBoundingBox componentwise and returns
true
if they are equal, false
otherwise.
Name | Type | Description |
---|---|---|
left |
OrientedBoundingBox | The first OrientedBoundingBox. |
right |
OrientedBoundingBox | The second OrientedBoundingBox. |
Returns:
true
if left and right are equal, false
otherwise.
staticCesium.OrientedBoundingBox.fromPoints(positions, result) → OrientedBoundingBox
Computes an instance of an OrientedBoundingBox of the given positions.
This is an implementation of Stefan Gottschalk's Collision Queries using Oriented Bounding Boxes solution (PHD thesis).
Reference: http://gamma.cs.unc.edu/users/gottschalk/main.pdf
Name | Type | Description |
---|---|---|
positions |
Array.<Cartesian3> |
optional
List of Cartesian3 points that the bounding box will enclose. |
result |
OrientedBoundingBox | optional The object onto which to store the result. |
Returns:
The modified result parameter or a new OrientedBoundingBox instance if one was not provided.
Example:
// Compute an object oriented bounding box enclosing two points.
var box = Cesium.OrientedBoundingBox.fromPoints([new Cesium.Cartesian3(2, 0, 0), new Cesium.Cartesian3(-2, 0, 0)]);
staticCesium.OrientedBoundingBox.fromRectangle(rectangle, minimumHeight, maximumHeight, ellipsoid, result) → OrientedBoundingBox
Computes an OrientedBoundingBox that bounds a
Rectangle
on the surface of an Ellipsoid
.
There are no guarantees about the orientation of the bounding box.
Name | Type | Default | Description |
---|---|---|---|
rectangle |
Rectangle | The cartographic rectangle on the surface of the ellipsoid. | |
minimumHeight |
Number |
0.0
|
optional The minimum height (elevation) within the tile. |
maximumHeight |
Number |
0.0
|
optional The maximum height (elevation) within the tile. |
ellipsoid |
Ellipsoid |
Ellipsoid.WGS84
|
optional The ellipsoid on which the rectangle is defined. |
result |
OrientedBoundingBox | optional The object onto which to store the result. |
Returns:
The modified result parameter or a new OrientedBoundingBox instance if none was provided.
Throws:
-
DeveloperError : rectangle.width must be between 0 and pi.
-
DeveloperError : rectangle.height must be between 0 and pi.
-
DeveloperError : ellipsoid must be an ellipsoid of revolution (
radii.x == radii.y
)
staticCesium.OrientedBoundingBox.intersectPlane(box, plane) → Intersect
Determines which side of a plane the oriented bounding box is located.
Name | Type | Description |
---|---|---|
box |
OrientedBoundingBox | The oriented bounding box to test. |
plane |
Plane | The plane to test against. |
Returns:
Intersect.INSIDE
if the entire box is on the side of the plane
the normal is pointing, Intersect.OUTSIDE
if the entire box is
on the opposite side, and Intersect.INTERSECTING
if the box
intersects the plane.
Determines whether or not a bounding box is hidden from view by the occluder.
Name | Type | Description |
---|---|---|
box |
OrientedBoundingBox | The bounding box surrounding the occludee object. |
occluder |
Occluder | The occluder. |
Returns:
true
if the box is not visible; otherwise false
.
Stores the provided instance into the provided array.
Name | Type | Default | Description |
---|---|---|---|
value |
OrientedBoundingBox | 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
staticCesium.OrientedBoundingBox.unpack(array, startingIndex, result) → OrientedBoundingBox
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 |
OrientedBoundingBox | optional The object into which to store the result. |
Returns:
The modified result parameter or a new OrientedBoundingBox instance if one was not provided.
clone(result) → OrientedBoundingBox
Duplicates this OrientedBoundingBox instance.
Name | Type | Description |
---|---|---|
result |
OrientedBoundingBox | optional The object onto which to store the result. |
Returns:
The modified result parameter or a new OrientedBoundingBox instance if one was not provided.
computePlaneDistances(position, direction, result) → Interval
The distances calculated by the vector from the center of the bounding box to position projected onto direction.
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 box.
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 box.
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 box from position in direction.
Computes the estimated distance squared from the closest point on a bounding box 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 boxes from back to front
boxes.sort(function(a, b) {
return b.distanceSquaredTo(camera.positionWC) - a.distanceSquaredTo(camera.positionWC);
});
Compares this OrientedBoundingBox against the provided OrientedBoundingBox componentwise and returns
true
if they are equal, false
otherwise.
Name | Type | Description |
---|---|---|
right |
OrientedBoundingBox | optional The right hand side OrientedBoundingBox. |
Returns:
true
if they are equal, false
otherwise.
intersectPlane(plane) → Intersect
Determines which side of a plane the oriented bounding box is located.
Name | Type | Description |
---|---|---|
plane |
Plane | The plane to test against. |
Returns:
Intersect.INSIDE
if the entire box is on the side of the plane
the normal is pointing, Intersect.OUTSIDE
if the entire box is
on the opposite side, and Intersect.INTERSECTING
if the box
intersects the plane.
Determines whether or not a bounding box is hidden from view by the occluder.
Name | Type | Description |
---|---|---|
occluder |
Occluder | The occluder. |
Returns:
true
if the sphere is not visible; otherwise false
.