de.grogra.vecmath.geom
Class Cone

java.lang.Object
  de.grogra.vecmath.geom.VolumeBase
      de.grogra.vecmath.geom.TransformableVolume
          de.grogra.vecmath.geom.FrustumBase
              de.grogra.vecmath.geom.Cone

All Implemented Interfaces:

Volume

Direct Known Subclasses:

Frustum

public class Cone
extends FrustumBase

This class represents the geometry of a cone. In local object coordinates, the tip is located at the origin, the axis points in the z-direction, and the half opening angle is 45 degrees.

Author:

Ole Kniemeyer

Field Summary

double	base The distance of the cone's base from the tip in local units.
boolean	baseOpen
boolean	rotateUV

Fields inherited from class de.grogra.vecmath.geom.FrustumBase

BASE, LATERAL, scaleV, TOP

Fields inherited from class de.grogra.vecmath.geom.TransformableVolume

m00, m01, m02, m10, m11, m12, m20, m21, m22, t0, t1, t2

Constructor Summary

Cone()

Method Summary

boolean	computeIntersections(Line line, int which, IntersectionList list, Intersection excludeStart, Intersection excludeEnd) Computes intersections between the boundary surface of this object and the specified line.
void	computeNormal(Intersection is, Vector3d normal) This method computes the unit normal vector of an intersection is which has been computed previously by the invocation of Volume.computeIntersections(de.grogra.vecmath.geom.Line, int, de.grogra.vecmath.geom.IntersectionList, de.grogra.vecmath.geom.Intersection, de.grogra.vecmath.geom.Intersection) on this volume.
void	computeTangents(Intersection is, Vector3d dpdu, Vector3d dpdv) This method computes the derivatives of the surface point (as function of the uv-coordinates, see Volume.computeUV(de.grogra.vecmath.geom.Intersection, javax.vecmath.Vector2d)) with respect to u and v at the intersection point.
void	computeUV(Intersection is, Vector2d uv) This method computes the uv-coordinates of an intersection point is which has been computed previously by the invocation of Volume.computeIntersections(de.grogra.vecmath.geom.Line, int, de.grogra.vecmath.geom.IntersectionList, de.grogra.vecmath.geom.Intersection, de.grogra.vecmath.geom.Intersection) on this volume.
boolean	contains(Tuple3d point, boolean open) Determines if the given point lies within this object.
double	getBase()
void	getExtent(Tuple3d min, Tuple3d max, Variables temp) Computes the extent of this volume, i.e., an axis-aligned bounding box between min and max.
double	getTop()
boolean	isBaseOpen()
boolean	isTopOpen()
boolean	isUVRotated()

Methods inherited from class de.grogra.vecmath.geom.FrustumBase

boxContainsBoundary, intersect

Methods inherited from class de.grogra.vecmath.geom.TransformableVolume

getDiscExtent, getDiscsExtent, getFrobeniusNorm, getObjectToWorldRotationScale, getTransformation, invalidate, invTransformPoint, scale, setTransformation, setTransformation, transformPoint, transformTranspose, transformVector, translate

Methods inherited from class de.grogra.vecmath.geom.VolumeBase

addConvexIntersections, getId, operator$and, operator$com, operator$or, operator$sub, setId

Methods inherited from class java.lang.Object

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

Field Detail

base

public double base

The distance of the cone's base from the tip in local units.

baseOpen

public boolean baseOpen

rotateUV

public boolean rotateUV

Constructor Detail

Cone

public Cone()

Method Detail

computeIntersections

public boolean computeIntersections(Line line,
                                    int which,
                                    IntersectionList list,
                                    Intersection excludeStart,
                                    Intersection excludeEnd)

Description copied from interface: Volume

Computes intersections between the boundary surface of this object and the specified line. The intersections are added to list in ascending order of distance (i.e., of Intersection.parameter), where the parameter has to lie between line.start and line.end. Implementations of this method must not clear or modify the existing intersections in list.

The parameter which has to be one of Intersection.ALL, Intersection.CLOSEST, Intersection.ANY. It determines if all intersections have to be added to the list, only the closest (minimal value of Intersection.parameter), or an arbitrary of the set of all intersections. Only in case of ALL, the return value of this method is precise.

If specific intersection points should be excluded from the list of computed intersections, they have to be specified in excludeStart and excludeEnd. The intersection point of excludeStart has to be the starting point of line, the intersection point of excludeEnd has to be the end point of line. The exclusion of intersections is a useful feature for ray-tracing, e.g., when a ray is re-emitted at an intersection point in another direction.

Parameters:

line - a line

which - one of Intersection.ALL, Intersection.CLOSEST, Intersection.ANY, this determines which intersections have to be added to list

list - the intersections are added to this list

excludeStart - intersection at start point which shall be excluded, or null

excludeEnd - intersection at end point which shall be excluded, or null

Returns:

true iff the beginning of the line lies within the volume (i.e., if the line starts within the volume or enters the volume at the starting point); however note that the returned value is valid only if which == Intersection.ALL

computeNormal

public void computeNormal(Intersection is,
                          Vector3d normal)

Description copied from interface: Volume

This method computes the unit normal vector of an intersection is which has been computed previously by the invocation of Volume.computeIntersections(de.grogra.vecmath.geom.Line, int, de.grogra.vecmath.geom.IntersectionList, de.grogra.vecmath.geom.Intersection, de.grogra.vecmath.geom.Intersection) on this volume.

Parameters:

is - a previously computed intersection

normal - resulting unit vector is placed in here

computeTangents

public void computeTangents(Intersection is,
                            Vector3d dpdu,
                            Vector3d dpdv)

Description copied from interface: Volume

This method computes the derivatives of the surface point (as function of the uv-coordinates, see Volume.computeUV(de.grogra.vecmath.geom.Intersection, javax.vecmath.Vector2d)) with respect to u and v at the intersection point.

Parameters:

is - a previously computed intersection

dpdu - resulting derivative with respect to u

dpdv - resulting derivative with respect to v

computeUV

public void computeUV(Intersection is,
                      Vector2d uv)

Description copied from interface: Volume

This method computes the uv-coordinates of an intersection point is which has been computed previously by the invocation of Volume.computeIntersections(de.grogra.vecmath.geom.Line, int, de.grogra.vecmath.geom.IntersectionList, de.grogra.vecmath.geom.Intersection, de.grogra.vecmath.geom.Intersection) on this volume.

Parameters:

is - a previously computed intersection

uv - resulting uv-coordinates are placed in here

contains

public boolean contains(Tuple3d point,
                        boolean open)

Description copied from interface: Volume

Determines if the given point lies within this object. If open is true, the interior of the volume is considered (the largest open set contained in the volume, i.e., excluding the boundary), otherwise the closure of the volume.

Parameters:

point - a point in global world coordinates

open - consider open or closed set

Returns:

true iff point is an element of the set

getBase

public double getBase()

getExtent

public void getExtent(Tuple3d min,
                      Tuple3d max,
                      Variables temp)

Description copied from interface: Volume

Computes the extent of this volume, i.e., an axis-aligned bounding box between min and max.

Parameters:

min - minimum coordinates of bounding box are placed in here

max - maximum coordinates of bounding box are placed in here

temp - has to be provided by the invoker, may be used in implementations

getTop

public double getTop()

isBaseOpen

public boolean isBaseOpen()

isTopOpen

public boolean isTopOpen()

isUVRotated

public boolean isUVRotated()