CesiumGeometry::OrientedBoundingBox Class Reference

A bounding volume defined as a closed and convex cuboid with any orientation. More...

#include <CesiumGeometry/OrientedBoundingBox.h>

Public Member Functions
	OrientedBoundingBox (const glm::dvec3 &center, const glm::dmat3 &halfAxes) noexcept
	Constructs a new instance. More...
constexpr const glm::dvec3 &	getCenter () const noexcept
	Gets the center of the box.
constexpr const glm::dmat3 &	getHalfAxes () const noexcept
	Gets the three orthogonal half-axes of the bounding box. Equivalently, the transformation matrix to rotate and scale a 2x2x2 cube centered at the origin.
constexpr const glm::dmat3 &	getInverseHalfAxes () const noexcept
	Gets the inverse transformation matrix, to rotate from world space to local space relative to the box.
constexpr const glm::dvec3 &	getLengths () const noexcept
	Gets the lengths of the box on each local axis respectively.
CullingResult	intersectPlane (const Plane &plane) const noexcept
	Determines on which side of a plane the bounding box is located. More...
double	computeDistanceSquaredToPosition (const glm::dvec3 &position) const noexcept
	Computes the distance squared from a given position to the closest point on this bounding volume. The bounding volume and the position must be expressed in the same coordinate system. More...
bool	contains (const glm::dvec3 &position) const noexcept
	Computes whether the given position is contained within the bounding box. More...
OrientedBoundingBox	transform (const glm::dmat4 &transformation) const noexcept
	Transforms this bounding box to another coordinate system using a 4x4 matrix. More...
AxisAlignedBox	toAxisAligned () const noexcept
	Converts this oriented bounding box to an axis-aligned bounding box.
BoundingSphere	toSphere () const noexcept
	Converts this oriented bounding box to a bounding sphere.

Static Public Member Functions
static OrientedBoundingBox	fromAxisAligned (const AxisAlignedBox &axisAligned) noexcept
	Creates an oriented bounding box from the given axis-aligned bounding box.
static OrientedBoundingBox	fromSphere (const BoundingSphere &sphere) noexcept
	Creates an oriented bounding box from the given bounding sphere.

Detailed Description

A bounding volume defined as a closed and convex cuboid with any orientation.

See also

BoundingSphere

BoundingRegion

Definition at line 22 of file OrientedBoundingBox.h.

Constructor & Destructor Documentation

OrientedBoundingBox()

CesiumGeometry::OrientedBoundingBox::OrientedBoundingBox ( const glm::dvec3 &  center, const glm::dmat3 &  halfAxes  )

inlinenoexcept

Constructs a new instance.

Parameters

center	The center of the box.
halfAxes	The three orthogonal half-axes of the bounding box. Equivalently, the transformation matrix to rotate and scale a 2x2x2 cube centered at the origin.

  // Create an OrientedBoundingBox using a transformation matrix, a position
  // where the box will be translated, and a scale.
  glm::dvec3 center = glm::dvec3(1.0, 0.0, 0.0);
  glm::dmat3 halfAxes = glm::dmat3(
      glm::dvec3(1.0, 0.0, 0.0),
      glm::dvec3(0.0, 3.0, 0.0),
      glm::dvec3(0.0, 0.0, 2.0));
 
  auto obb = OrientedBoundingBox(center, halfAxes);

Definition at line 34 of file OrientedBoundingBox.h.

Member Function Documentation

computeDistanceSquaredToPosition()

double CesiumGeometry::OrientedBoundingBox::computeDistanceSquaredToPosition ( const glm::dvec3 &  position ) const

noexcept

Computes the distance squared from a given position to the closest point on this bounding volume. The bounding volume and the position must be expressed in the same coordinate system.

Parameters

position

The position

Returns

The estimated distance squared from the bounding box to the point.

  // Sort bounding boxes from back to front
  glm::dvec3 cameraPosition = anyOldCameraPosition();
  std::vector<OrientedBoundingBox> boxes = anyOldBoxArray();
  std::sort(boxes.begin(), boxes.end(), [&cameraPosition](auto& a, auto& b) {
    return a.computeDistanceSquaredToPosition(cameraPosition) >
           b.computeDistanceSquaredToPosition(cameraPosition);
  });

contains()

bool CesiumGeometry::OrientedBoundingBox::contains ( const glm::dvec3 &  position ) const

noexcept

Computes whether the given position is contained within the bounding box.

Parameters

position

The position.

Returns

Whether the position is contained within the bounding box.

intersectPlane()

CullingResult CesiumGeometry::OrientedBoundingBox::intersectPlane ( const Plane &  plane ) const

noexcept

Determines on which side of a plane the bounding box is located.

Parameters

plane

The plane to test against.

Returns

The CullingResult:

• Inside if the entire box is on the side of the plane the normal is pointing.
• Outside if the entire box is on the opposite side.
• Intersecting if the box intersects the plane.

transform()

OrientedBoundingBox CesiumGeometry::OrientedBoundingBox::transform ( const glm::dmat4 &  transformation ) const

noexcept

Transforms this bounding box to another coordinate system using a 4x4 matrix.

Parameters

transformation

The transformation.

Returns

The oriented bounding box in the new coordinate system.

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The documentation for this class was generated from the following file:

• /home/runner/work/cesium-native/cesium-native/CesiumGeometry/include/CesiumGeometry/OrientedBoundingBox.h