maspack.geometry

Class AABB

java.lang.Object

maspack.geometry.BVNode

maspack.geometry.AABB

All Implemented Interfaces:

IsRenderable

public class AABB
extends BVNode

Field Summary

Fields inherited from interface maspack.render.IsRenderable

TRANSPARENT, TWO_DIMENSIONAL

Constructor Summary

Constructors

Constructor and Description
AABB()
AABB(double minx, double miny, double minz, double maxx, double maxy, double maxz)

Method Summary

Modifier and Type	Method and Description
boolean	containsPoint(Point3d pnt) Returns true if this bounding volume contains a prescribed point.
double	distanceAlongLine(Point3d origin, Vector3d dir, double min, double max) Code is modified from "An Efficient and Robust Ray-Box Intersection Algorithm", Amy Williams, Steve Barrus, R.
double	distanceToPoint(Point3d pnt) Returns the distance of a point to this bounding volume, or 0 if the point is on or inside it.
void	getCenter(Vector3d center) Returns a center point for this bounding volume.
void	getHalfWidths(Vector3d hw)
double	getRadius() Returns an approximate "radius" for this bounding volume.
boolean	intersectsLine(double[] dists, Point3d origin, Vector3d dir, double min, double max) Returns true if this bounding volume intersects a line.
boolean	intersectsLineSegment(Point3d p1, Point3d p2) Returns true if this bounding volume intersects a line segment.
boolean	intersectsPlane(Vector3d n, double d) Returns true if this bounding volume intersects a plane described by
boolean	intersectsSphere(Point3d pnt, double r) Returns true if this bounding volume intersects a sphere.
boolean	isContained(Boundable[] boundables, double tol) Returns true if an entire set of elements is contained within this bounding volume.
void	prerender(RenderList list) Called prior to rendering to allow this object to update the internal state required for rendering (such as by caching rendering coordinates).
void	render(Renderer renderer, int flags) Render this object using the functionality of the supplied Renderer.
void	scale(double s) Scales this bounding volume node by the indicated scale factor s.
void	set(AABB aabb, double margin)
void	set(Boundable[] elementList, int nelems, double margin)
void	setMaximums(double maxx, double maxy, double maxz)
void	setMinimums(double minx, double miny, double minz)
boolean	update(double margin) Update node
void	updateBounds(Vector3d min, Vector3d max) Update the minimum and maximum points for this object.
void	updateForAABB(AABB aabb, double margin) Grow this AABB if necessary to accommodate anothor aabb.
boolean	updateForPoint(Point3d pnt, double margin)

Methods inherited from class maspack.geometry.BVNode

addChild, getDepth, getElements, getFirstChild, getNext, getNumber, getNumElements, getParent, getRenderHints, isLeaf, numChildren, setElements, setNumber, setParent, updateFor

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AABB

public AABB()

AABB

public AABB(double minx,
            double miny,
            double minz,
            double maxx,
            double maxy,
            double maxz)

Method Detail

getRadius

public double getRadius()

Description copied from class: BVNode

Returns an approximate "radius" for this bounding volume. This does not have to be precise, but should reflect roughly the maximum distance of the volume boundary from it's center.

Specified by:

getRadius in class BVNode

Returns:

approximate radius of the volume

getCenter

public void getCenter(Vector3d center)

Description copied from class: BVNode

Returns a center point for this bounding volume.

Specified by:

getCenter in class BVNode

Parameters:

center - returns to center point

getHalfWidths

public void getHalfWidths(Vector3d hw)

setMinimums

public void setMinimums(double minx,
                        double miny,
                        double minz)

setMaximums

public void setMaximums(double maxx,
                        double maxy,
                        double maxz)

containsPoint

public boolean containsPoint(Point3d pnt)

Description copied from class: BVNode

Returns true if this bounding volume contains a prescribed point.

Specified by:

containsPoint in class BVNode

Parameters:

pnt - point to be tested

Returns:

true if this bounding volume contains pnt.

intersectsSphere

public boolean intersectsSphere(Point3d pnt,
                                double r)

Description copied from class: BVNode

Returns true if this bounding volume intersects a sphere. By specifying a negative value for the radius, the method can be used as a test to see if the center point is located a certain distance within the bounding volume.

Specified by:

intersectsSphere in class BVNode

Parameters:

pnt - center point of the sphere

r - radius of the sphere

Returns:

true if this bounding volume intersects the sphere

intersectsLine

public boolean intersectsLine(double[] dists,
                              Point3d origin,
                              Vector3d dir,
                              double min,
                              double max)

Description copied from class: BVNode

Returns true if this bounding volume intersects a line. The line is described by a point and a direction, such that points x along the line can be described by a parameter s according to

 x = origin + s dir
 

The line can be given finite bounds by specifying maximum and minimum bounds for s.

Specified by:

intersectsLine in class BVNode

Parameters:

dists - if non-null, returns the lower and upper values of s that define the intersection region

origin - originating point for the line

dir - direction of the line

min - minimum s value for the line, or -infinity if there is no minimum value

max - maximum s value for the line, or +infinity if there is no maximum value

Returns:

true if this bounding volume intersects the line

intersectsPlane

public boolean intersectsPlane(Vector3d n,
                               double d)

Description copied from class: BVNode

Returns true if this bounding volume intersects a plane described by

 n^T x = d
 

Specified by:

intersectsPlane in class BVNode

Parameters:

n - normal direction of the plane

d - dot product offset

Returns:

true if this bounding volume intersects the plane

intersectsLineSegment

public boolean intersectsLineSegment(Point3d p1,
                                     Point3d p2)

Description copied from class: BVNode

Returns true if this bounding volume intersects a line segment.

Specified by:

intersectsLineSegment in class BVNode

Parameters:

p1 - first segment end point

p2 - second segment end point

Returns:

true if this bounding volume intersects the line segment.

set

public void set(Boundable[] elementList,
                int nelems,
                double margin)

set

public void set(AABB aabb,
                double margin)

updateForPoint

public boolean updateForPoint(Point3d pnt,
                              double margin)

update

public boolean update(double margin)

Description copied from class: BVNode

Update node

Parameters:

margin - supplied margin around boundary

Returns:

true if node was modified

isContained

public boolean isContained(Boundable[] boundables,
                           double tol)

Description copied from class: BVNode

Returns true if an entire set of elements is contained within this bounding volume. This method is mainly intended for diagnostic purposes.

Specified by:

isContained in class BVNode

Parameters:

boundables - set of boundable elements to check

tol - specifies the minimum amount by which each element must be inside

updateForAABB

public void updateForAABB(AABB aabb,
                          double margin)

Grow this AABB if necessary to accommodate anothor aabb.

Parameters:

aabb - AABB that should fit inside this box

margin - additional tolerance margin

distanceToPoint

public double distanceToPoint(Point3d pnt)

Description copied from class: BVNode

Returns the distance of a point to this bounding volume, or 0 if the point is on or inside it.

Specified by:

distanceToPoint in class BVNode

Parameters:

pnt - point to check distance for

Returns:

distance of pnt to this volume

distanceAlongLine

public double distanceAlongLine(Point3d origin,
                                Vector3d dir,
                                double min,
                                double max)

Code is modified from "An Efficient and Robust Ray-Box Intersection Algorithm", Amy Williams, Steve Barrus, R. Keith Morley, Peter Shirley, University of Utah.

Specified by:

distanceAlongLine in class BVNode

Parameters:

origin - originating point for the line

dir - direction of the line

min - minimum s value for the line, or -infinity if there is no minimum value

max - maximum s value for the line, or +infinity if there is no maximum value

Returns:

distance of the point to the volume along the line

updateBounds

public void updateBounds(Vector3d min,
                         Vector3d max)

Description copied from interface: IsRenderable

Update the minimum and maximum points for this object. In an x-y-z coordinate system with x directed to the right and y directed upwards, the minimum and maximum points can be thought of as defining the left-lower-far and right-upper-near corners of a bounding cube. This method should only reduce the elements of the minimum point and increase the elements of the maximum point, since it may be used as part of an iteration to determine the bounding cube for several different objects.

Parameters:

min - minimum point

max - maximum point

prerender

public void prerender(RenderList list)

Description copied from interface: IsRenderable

Called prior to rendering to allow this object to update the internal state required for rendering (such as by caching rendering coordinates). The object may add internal objects to the list of objects being rendered, by calling

list.addIfVisible (obj);

for each of the objects in question.

Parameters:

list - list of objects to be rendered

render

public void render(Renderer renderer,
                   int flags)

Description copied from interface: IsRenderable

Render this object using the functionality of the supplied Renderer.

Parameters:

renderer - provides the functionality used to perform the rendering.

flags - flags that may be used to control different aspects of the rendering. Flags are defined in Renderer and currently include Renderer.HIGHLIGHT and Renderer.SORT_FACES.

scale

public void scale(double s)

Scales this bounding volume node by the indicated scale factor s. This can be used to enlarge a volume to accommodate a margin.

Parameters:

s - scaling factor