de.grogra.vecmath.geom
Class SimpleUnion

java.lang.Object
  extended by de.grogra.vecmath.geom.VolumeBase
      extended by de.grogra.vecmath.geom.CompoundVolume
          extended by de.grogra.vecmath.geom.UnionBase
              extended by de.grogra.vecmath.geom.SimpleUnion
All Implemented Interfaces:
Volume

public class SimpleUnion
extends UnionBase

An instance of this class represents a simple union of a list of volumes. In constrast to CSGUnion, all intersections of volume components are reported so that inner surfaces are not removed.

Author:
Ole Kniemeyer

Field Summary
 
Fields inherited from class de.grogra.vecmath.geom.CompoundVolume
volumes
 
Constructor Summary
SimpleUnion()
           
 
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.
 
Methods inherited from class de.grogra.vecmath.geom.UnionBase
contains, getExtent
 
Methods inherited from class de.grogra.vecmath.geom.CompoundVolume
boxContainsBoundary, computeNormal, computeTangents, computeUV
 
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
 

Constructor Detail

SimpleUnion

public SimpleUnion()
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