An oriented bounding box that optionally allows building an OBB tree. More...

#include <OBB.h>

Inheritance diagram for Moby::OBB:

Public Member Functions
	OBB (const OBB &obb)

	OBB (const Point3d &center, const Ravelin::Matrix3d &R, const Ravelin::Vector3d &l)

	OBB (const OBB &o, const Ravelin::Vector3d &v)

OBB &	operator= (const OBB &obb)
	Copies an OBB. More...

virtual void	transform (const Ravelin::Transform3d &T, BV *result) const
	Transforms the OBB using the given transform.

virtual BVPtr	calc_swept_BV (CollisionGeometryPtr g, const Ravelin::SVelocityd &v) const
	Calculates the velocity-expanded OBB for a body.

virtual bool	intersects (const LineSeg3 &seg, double &tmin, double tmax, Point3d &q) const
	Determines whether a line segment intersects the bounding volume.

virtual bool	outside (const Point3d &point, double tol=NEAR_ZERO) const
	Determines whether a point is outside the bounding volume.

virtual std::ostream &	to_vrml (std::ostream &out, const Ravelin::Pose3d &T) const
	Outputs the OBB in VRML format to the given stream.

unsigned	calc_size () const
	Constructs an OBB from a triangle mesh using the mesh inertia method [Ericson, 2003]. More...

XMLTreePtr	save_to_xml_tree () const
	Saves a OBB hiearchy to a XMLTree.

virtual boost::shared_ptr < const Ravelin::Pose3d >	get_relative_pose () const
	Gets the associated pose for this bounding volume.

virtual Point3d	get_lower_bounds () const
	Gets the lower bounds on the OBB.

virtual Point3d	get_upper_bounds () const
	Gets the upper bounds on the OBB.

template<class ForwardIterator >
void	expand_to_fit (ForwardIterator begin, ForwardIterator end)
	Expands this OBB (if necessary) to fit the given points. More...

template<class ForwardIterator >
	OBB (ForwardIterator begin, ForwardIterator end)
	Computes an OBB from a set of points. More...

template<class OutputIterator >
OutputIterator	get_vertices (OutputIterator begin) const
	Gets the eight vertices of the bounding box. More...

virtual double	calc_volume () const
	Calculates 1/8th of the volume of the bounding box.

template<class ForwardIterator >
OBB	calc_low_dim_OBB (ForwardIterator begin, ForwardIterator end)
	Computes the minimum OBB from a set of lower dimensional (< 3d) points. More...

template<class ForwardIterator >
OBB	calc_min_volume_OBB (ForwardIterator begin, ForwardIterator end)
	Computes the minimum OBB from a set of points. More...

template<class ForwardIterator >
	OBB (ForwardIterator begin, ForwardIterator end)
	Computes an OBB from a set of points. More...

template<class ForwardIterator >
void	expand_to_fit (ForwardIterator begin, ForwardIterator end)
	Expands this OBB (if necessary) to fit the given points. More...

template<class ForwardIterator >
void	align (ForwardIterator begin, ForwardIterator end, const Ravelin::Vector3d &d1, Ravelin::Vector3d &d2)
	Aligns this OBB with the minimum area bounding rectangle projected along the first dimension of the OBB.

template<class OutputIterator >
OutputIterator	get_vertices (OutputIterator begin) const
	Gets the eight vertices of the bounding box. More...

template<class ForwardIterator >
void	calc_lengths (const Ravelin::Vector3d &d1, const Ravelin::Vector3d &d2, const Ravelin::Vector3d &d3, const Point3d &center, ForwardIterator begin, ForwardIterator end, double lengths[3])

Public Member Functions inherited from Moby::BV
BVPtr	get_this ()

boost::shared_ptr< const BV >	get_this () const

bool	is_leaf () const

template<class OutputIterator >
OutputIterator	get_all_BVs (OutputIterator begin) const
	Gets all BV nodes. More...

template<class OutputIterator >
OutputIterator	get_all_leafs (OutputIterator begin) const
	Gets all leaf nodes.

template<class OutputIterator >
OutputIterator	get_all_BVs (OutputIterator begin) const
	Gets all BV nodes. More...

template<class OutputIterator >
OutputIterator	get_all_leafs (OutputIterator begin) const
	Gets all leaf nodes.

template<class OutputIterator >
OutputIterator	intersect_BV_trees (BVPtr a, BVPtr b, const Ravelin::Transform3d &aTb, const Ravelin::Transform3d &bTa, OutputIterator output_begin)
	Intersects two BV trees; returns list of all leaf-level intersecting BVs. More...

Static Public Member Functions
static double	calc_sq_dist (const OBB &o, const Point3d &p)
	Computes the squared distance from a point to an OBB.

static double	calc_dist (const OBB &a, const OBB &b, Point3d &cpa, Point3d &cpb)
	Determines the distance between two OBBs.

static double	calc_dist (const OBB &a, const OBB &b, const Ravelin::Transform3d &aTb, Point3d &cpa, Point3d &cpb)

static bool	intersects (const OBB &a, const OBB &b)
	Determines whether two OBBs intersect another. More...

static bool	intersects (const OBB &a, const OBB &b, const Ravelin::Transform3d &aTb)

static bool	intersects (const OBB &a, const LineSeg3 &seg, double &tmin, double tmax, Point3d &q)
	Determines whether an OBB and a line/ray/line segment intersect. More...

static bool	outside (const OBB &a, const Point3d &point, double tol=NEAR_ZERO)
	Determines whether a point is outside a OBB to within the given tolerance.

static OBBPtr	load_from_xml (boost::shared_ptr< const XMLTree > root)
	Loads an OBB hierarchy from a XML tree.

template<class ForwardIterator >
static OBB	calc_min_volume_OBB (ForwardIterator begin, ForwardIterator end)
	Computes the minimum OBB from a set of points. More...

Static Public Member Functions inherited from Moby::BV
static bool	intersects (BVPtr a, BVPtr b)
	Convenience method.

static bool	intersects (BVPtr a, BVPtr b, const Ravelin::Transform3d &T)
	Convenience method.

static double	calc_distance (BVPtr a, BVPtr b, Point3d &cp1, Point3d &cp2)
	Convenience method.

static double	calc_distance (BVPtr a, BVPtr b, const Ravelin::Transform3d &aTb, Point3d &cp1, Point3d &cp2)
	Convenience method.

static bool	intersects (const BV a, const BV b)
	Computes whether two abstract bounding volumes intersect.

static bool	intersects (const BV a, const BV b, const Ravelin::Transform3d &T)

static double	calc_distance (const BV a, const BV b, Point3d &cp1, Point3d &cp2)
	Computes the distance between two abstract bounding volumes and stores the closest points. More...

static double	calc_distance (const BV a, const BV b, const Ravelin::Transform3d &aTb, Point3d &cp1, Point3d &cp2)

template<class OutputIterator >
static OutputIterator	intersect_BV_trees (BVPtr a, BVPtr b, const Ravelin::Transform3d &aTb, const Ravelin::Transform3d &bTa, OutputIterator output_begin)
	Intersects two BV trees; returns list of all leaf-level intersecting BVs. More...

Public Attributes
Point3d	center
	Center of the bounding box.

Ravelin::Vector3d	l
	Half-lengths of the OBBs in the three axes directions (i.e., in the box frame)

Ravelin::Matrix3d	R
	Orientation of this OBB.

Public Attributes inherited from Moby::BV
boost::shared_ptr< void >	userdata
	Userdata for the BV.

CollisionGeometryPtr	geom
	The collision geometry associated with this bounding volume.

std::list< BVPtr >	children
	The children of this BV.

Detailed Description

An oriented bounding box that optionally allows building an OBB tree.

Note: the OBB is generally constructed such that its frame is aligned with that of the underlying rigid body (or collision geometry). Therefore, the center of the OBB is computed relative to the center-of-mass of the body (or the center of the geometry). The orientation of the OBB will always be identical to the orientation of the rigid body (or collision geometry).

Constructor & Destructor Documentation

template<class ForwardIterator >

Moby::OBB::OBB	(	ForwardIterator	begin,
		ForwardIterator	end
	)

Computes an OBB from a set of points.

Parameters

begin	an iterator to type Point3d
end	an iterator to type Point3d Algorithm taken from [Ericson, 2005]

template<class ForwardIterator >

Moby::OBB::OBB	(	ForwardIterator	begin,
		ForwardIterator	end
	)

Computes an OBB from a set of points.

Parameters

begin	an iterator to type Point3d
end	an iterator to type Point3d Algorithm taken from [Ericson, 2005]

References Moby::IndexedTri::a, Moby::IndexedTri::b, and Moby::IndexedTri::c.

Member Function Documentation

template<class ForwardIterator >

OBB Moby::OBB::calc_low_dim_OBB	(	ForwardIterator	begin,
		ForwardIterator	end
	)

Computes the minimum OBB from a set of lower dimensional (< 3d) points.

Parameters

begin	an iterator to type Point3d
end	an iterator to type Point3d

References center, l, and R.

template<class ForwardIterator >

OBB Moby::OBB::calc_min_volume_OBB	(	ForwardIterator	begin,
		ForwardIterator	end
	)

static

Computes the minimum OBB from a set of points.

Parameters

begin	an iterator to type Point3d
end	an iterator to type Point3d Algorithm taken from http://www.geometrictools.com - thanks Dave Eberly!

template<class ForwardIterator >

OBB Moby::OBB::calc_min_volume_OBB	(	ForwardIterator	begin,
		ForwardIterator	end
	)

Computes the minimum OBB from a set of points.

Parameters

begin	an iterator to type Point3d
end	an iterator to type Point3d Algorithm taken from http://www.geometrictools.com - thanks Dave Eberly!

References calc_volume(), center, Moby::IndexedTriArray::determine_edge_facet_map(), Moby::IndexedTriArray::determine_vertex_edge_map(), Moby::IndexedTriArray::get_triangle(), Moby::IndexedTriArray::get_vertices(), Moby::IndexedTriArray::is_coplanar(), l, and R.

unsigned OBB::calc_size ( ) const

Constructs an OBB from a triangle mesh using the mesh inertia method [Ericson, 2003].

Requires a O(n) operation to compute the inertial properties of the triangle meshCalculates the size (number of elements in) of an OBB tree

template<class ForwardIterator >

void Moby::OBB::expand_to_fit	(	ForwardIterator	begin,
		ForwardIterator	end
	)

Expands this OBB (if necessary) to fit the given points.

Parameters

begin	an iterator to the beginning of a container of type Ravelin:Point3d:
end	an iterator to the end of a container of type Point3d

template<class ForwardIterator >

void Moby::OBB::expand_to_fit	(	ForwardIterator	begin,
		ForwardIterator	end
	)

Expands this OBB (if necessary) to fit the given points.

Parameters

begin	an iterator to the beginning of a container of type Ravelin:Point3d:
end	an iterator to the end of a container of type Point3d

template<class OutputIterator >

OutputIterator Moby::OBB::get_vertices ( OutputIterator begin ) const

Gets the eight vertices of the bounding box.

Note: vertices are output in no particular order

template<class OutputIterator >

OutputIterator Moby::OBB::get_vertices ( OutputIterator begin ) const

Gets the eight vertices of the bounding box.

Note: vertices are output in no particular order

bool OBB::intersects	(	const OBB &	a,
		const OBB &	b
	)

static

Determines whether two OBBs intersect another.

Code adapted from [Ericson, 2005]

References get_relative_pose().

Referenced by intersects().

bool OBB::intersects	(	const OBB &	a,
		const LineSeg3 &	seg,
		double &	tmin,
		double	tmax,
		Point3d &	q
	)

static

Determines whether an OBB and a line/ray/line segment intersect.

When intersecting, return intersection distance tmin and point q of intersection.

Parameters

a	the OBB to check for intersection
seg	the line segment to check for intersection
tmin	on entry, contains the minimum value of the line parameter- for a line segment, this will generally be 0; when an intersection occurs, this will contain the distance of intersection from the tmin that was input on return
tmax	the maximum value of the line parameter- for a line segment, this will generally be 1
q	contains the point of intersection, if any, on return

Returns: true if the OBB and line intersect, false otherwise

Note: code adapted from [Ericson, 2005], pp. 180-181

References center, get_relative_pose(), and R.

OBB & OBB::operator= ( const OBB & obb )

Copies an OBB.

Note: userdata and node info (children) are not copied

References center, Moby::BV::geom, l, and R.

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

/home/drum/Moby/include/Moby/OBB.h
/home/drum/Moby/include/Moby/OBB.inl
/home/drum/Moby/src/OBB.cpp

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation