maspack.collision

Class SurfaceMeshIntersector

java.lang.Object

maspack.collision.SurfaceMeshIntersector

public class SurfaceMeshIntersector
extends java.lang.Object

A collider that determines the intersection between two meshes by first identifying and tracing the intersection contours between the meshes, and then using these to determine the interpenetration regions.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SurfaceMeshIntersector.CSG Describes CSG and intersection operations between two meshes, mesh0 and mesh1.
static class	SurfaceMeshIntersector.RegionType Describes which penetration regions should be computed for a particular mesh intersecting with another mesh.

Field Summary

Fields

Modifier and Type	Field and Description
boolean	coincidentError
static boolean	debug
static boolean	debug2
static RigidTransform3d	debugTBW
boolean	mySilentP
static int	numClosestIntersectionCalls
static int	numEdgeAdds
static int	numRegularCalls
static int	numRobustCalls
static int	numRobustClosestIntersectionCalls
boolean	triangulationError
static boolean	writeErrorFiles

Constructor Summary

Constructors

Constructor and Description
SurfaceMeshIntersector()

Method Summary

Modifier and Type	Method and Description
Vertex3d	addEmptyFaceVertices(Vertex3dList poly, HalfEdge edge, IntersectionPoint emip, IntersectionPoint xmip, PenetrationRegion region, Vertex3d curVtx, boolean clockwise, boolean debug)
PolygonalMesh	createCSGMesh(ContactInfo cinfo) Computes the boundary mesh formed by the union of the penetration regions associated with two meshes.
PolygonalMesh	createCSGMeshOld(ContactInfo cinfo)
HalfEdge	edgeIntersectingFace(Face face, Face otherFace, IntersectionContour contour)
java.util.ArrayList<IntersectionContour>	findContours(PolygonalMesh mesh0, PolygonalMesh mesh1)
ContactInfo	findContoursAndRegions(PolygonalMesh mesh0, PolygonalMesh mesh1) Finds the intersection contours between two meshes, as described by findContours(maspack.geometry.PolygonalMesh, maspack.geometry.PolygonalMesh), and then processes these further to determine inside penetration regions on each mesh.
ContactInfo	findContoursAndRegions(PolygonalMesh mesh0, SurfaceMeshIntersector.RegionType regions0, PolygonalMesh mesh1, SurfaceMeshIntersector.RegionType regions1) Finds the intersection contours between two meshes, as described by findContours(maspack.geometry.PolygonalMesh, maspack.geometry.PolygonalMesh), and then processes these further to determine either the inside or outside penetration regions for each mesh.
PolygonalMesh	findDifference01(PolygonalMesh mesh0, PolygonalMesh mesh1) Find the polyhedral boundary of the CSG (constructive solid geometry) difference of two meshes, given by
PolygonalMesh	findDifference10(PolygonalMesh mesh0, PolygonalMesh mesh1) Find the polyhedral boundary of the CSG (constructive solid geometry) difference of two meshes, given by
PolygonalMesh	findIntersection(PolygonalMesh mesh0, PolygonalMesh mesh1) Find the polyhedral boundary of the CSG (constructive solid geometry) intersection of two meshes.
int	findIntersectionContours(java.util.ArrayList<IntersectionContour> contours, Boundable[] elems0, Boundable[] elems1, boolean edgeOnMesh0) Look for intersecting triangles in elems0 and elems1.
PolygonalMesh	findMesh0Inside(PolygonalMesh mesh0, PolygonalMesh mesh1) Find the polyhedral portion of mesh0 that is inside the intersection region between mesh0 and mesh1.
PolygonalMesh	findMesh0Outside(PolygonalMesh mesh0, PolygonalMesh mesh1) Find the polyhedral portion of mesh0 that is outside the intersection region between mesh0 and mesh1.
PolygonalMesh	findMesh1Inside(PolygonalMesh mesh0, PolygonalMesh mesh1) Find the polyhedral portion of mesh1 that is inside the intersection region between mesh0 and mesh1.
PolygonalMesh	findMesh1Outside(PolygonalMesh mesh0, PolygonalMesh mesh1) Find the polyhedral portion of mesh1 that is outside the intersection region between mesh0 and mesh1.
ContactInfo	findRegions(SurfaceMeshIntersector.RegionType regions0, SurfaceMeshIntersector.RegionType regions1) Finds either the inside or outside penetration regions for the meshes and contours associated with the most recent call to either findContours(maspack.geometry.PolygonalMesh, maspack.geometry.PolygonalMesh), findContoursAndRegions(PolygonalMesh,PolygonalMesh), or findContoursAndRegions(PolygonalMesh,RegionType,PolygonalMesh,RegionType).
PolygonalMesh	findUnion(PolygonalMesh mesh0, PolygonalMesh mesh1) Find the polyhedral boundary of the CSG (constructive solid geometry) union of two meshes.
boolean	getRemoveZeroAreaFaces() Queries whether zero area faces should be removed when constructing CSG primitives.
boolean	getSilent()
void	setRemoveZeroAreaFaces(boolean enable) Sets whether zero area faces should be removed when constructing CSG primitives.
void	setSilent(boolean silent)
java.lang.String	toString(IntersectionPoint p)
java.lang.String	toString(IntersectionPoint p, RigidTransform3d T) Comprehensive string representation of a mesh intersection point, showing most relevant information.

Methods inherited from class java.lang.Object

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

Field Detail

writeErrorFiles

public static boolean writeErrorFiles

mySilentP

public boolean mySilentP

debug

public static boolean debug

debug2

public static boolean debug2

debugTBW

public static RigidTransform3d debugTBW

triangulationError

public boolean triangulationError

coincidentError

public boolean coincidentError

numRegularCalls

public static int numRegularCalls

numRobustCalls

public static int numRobustCalls

numEdgeAdds

public static int numEdgeAdds

numClosestIntersectionCalls

public static int numClosestIntersectionCalls

numRobustClosestIntersectionCalls

public static int numRobustClosestIntersectionCalls

Constructor Detail

SurfaceMeshIntersector

public SurfaceMeshIntersector()

Method Detail

getSilent

public boolean getSilent()

setSilent

public void setSilent(boolean silent)

getRemoveZeroAreaFaces

public boolean getRemoveZeroAreaFaces()

Queries whether zero area faces should be removed when constructing CSG primitives. See setRemoveZeroAreaFaces(boolean).

setRemoveZeroAreaFaces

public void setRemoveZeroAreaFaces(boolean enable)

Sets whether zero area faces should be removed when constructing CSG primitives. A face is taken to have zero area if its area is less that a tolerance given by double precision times the square of the maximum ``radius'' of the two meshes.

toString

public java.lang.String toString(IntersectionPoint p)

toString

public java.lang.String toString(IntersectionPoint p,
                                 RigidTransform3d T)

Comprehensive string representation of a mesh intersection point, showing most relevant information. Used for debugging. The string contains the following information: 1) index of the point with respect to the contour 2) the degeneracy code for the intersection (as a two digit hex number) 3) 'C' if the point is coincident, or ' ' otherwise 4) the point's edge and face, if edge belongs to mesh, or the point's face and edge 5) the segment faces of the point with respect to the mesh and the other mesh (or blank if this is the last point of an open contour) 6) the point's coordinates

findContours

public java.util.ArrayList<IntersectionContour> findContours(PolygonalMesh mesh0,
                                                             PolygonalMesh mesh1)

findRegions

public ContactInfo findRegions(SurfaceMeshIntersector.RegionType regions0,
                               SurfaceMeshIntersector.RegionType regions1)

Finds either the inside or outside penetration regions for the meshes and contours associated with the most recent call to either findContours(maspack.geometry.PolygonalMesh, maspack.geometry.PolygonalMesh), findContoursAndRegions(PolygonalMesh,PolygonalMesh), or findContoursAndRegions(PolygonalMesh,RegionType,PolygonalMesh,RegionType). The type of region (inside, outside, or none) that should be computed for each mesh is controlled by the arguments regions0 and regions1. This method functions identically to findContoursAndRegions(PolygonalMesh,RegionType,PolygonalMesh,RegionType), except that the meshes and contours are those associated with the last of the aforementioned calls. If no such previous call was made, this method throws an IllegalStateException. If the call did not result in an intersection, this method returns null.

Parameters:

regions0 - specifies which type of penetration regions should be computed for the first mesh

regions1 - specifies which type of penetration regions should be computed for the second mesh

Returns:

a ContactInfo structure containing the computed region information, or null if no intersection was previously found.

findContoursAndRegions

public ContactInfo findContoursAndRegions(PolygonalMesh mesh0,
                                          PolygonalMesh mesh1)

Finds the intersection contours between two meshes, as described by findContours(maspack.geometry.PolygonalMesh, maspack.geometry.PolygonalMesh), and then processes these further to determine inside penetration regions on each mesh. This is identical to the call

   findContoursAndRegions (mesh0, true, mesh1, true);
 

and for more information see the documentation for findContoursAndRegions(PolygonalMesh,RegionType,PolygonalMesh,RegionType).

Parameters:

mesh0 - first mesh

mesh1 - second mesh

Returns:

ContactInfo object containing the contours and regions, or null if there is no intersection.

findContoursAndRegions

public ContactInfo findContoursAndRegions(PolygonalMesh mesh0,
                                          SurfaceMeshIntersector.RegionType regions0,
                                          PolygonalMesh mesh1,
                                          SurfaceMeshIntersector.RegionType regions1)

Finds the intersection contours between two meshes, as described by findContours(maspack.geometry.PolygonalMesh, maspack.geometry.PolygonalMesh), and then processes these further to determine either the inside or outside penetration regions for each mesh. These are the sub-regions of the mesh which are either inside or outside of the intersection volume. The type of region (inside, outside, or none) that should be computed for each mesh is controlled by the arguments regions0 and regions1. Contours that do not partition a mesh into distinct regions are ignored.

The region information for each mesh, along with the generated contours, is returned in a ContactInfo object, for which the methods ContactInfo.getContours(), getRegions(0), and getRegions(1) can be used to query the contours and the respective regions for mesh0 and mesh1.

If no intersection contours are discovered between the two meshes, the contour list returned in the ContactInfo will have zero length.

Parameters:

mesh0 - first mesh

regions0 - specifies which type of penetration regions should be computed for mesh0

mesh1 - second mesh

regions1 - specifies which type of penetration regions should be computed for mesh1

Returns:

ContactInfo object containing the contours and regions

findIntersection

public PolygonalMesh findIntersection(PolygonalMesh mesh0,
                                      PolygonalMesh mesh1)

Find the polyhedral boundary of the CSG (constructive solid geometry) intersection of two meshes. The resulting mesh will be empty if mesh0 and mesh1 do not intersect.

Parameters:

mesh0 - first intersecting mesh

mesh1 - second intersecting mesh

Returns:

mesh describing the intersection boundary, or null if no such mesh exists.

findUnion

public PolygonalMesh findUnion(PolygonalMesh mesh0,
                               PolygonalMesh mesh1)

Find the polyhedral boundary of the CSG (constructive solid geometry) union of two meshes.

Parameters:

mesh0 - first intersecting mesh

mesh1 - second intersecting mesh

Returns:

mesh describing the union boundary.

findDifference01

public PolygonalMesh findDifference01(PolygonalMesh mesh0,
                                      PolygonalMesh mesh1)

Find the polyhedral boundary of the CSG (constructive solid geometry) difference of two meshes, given by

 mesh0 - mesh1
 

The resulting mesh will be empty if mesh0 is entirely inside mesh1.

Parameters:

mesh0 - first intersecting mesh

mesh1 - second intersecting mesh

Returns:

mesh describing the difference boundary.

findDifference10

public PolygonalMesh findDifference10(PolygonalMesh mesh0,
                                      PolygonalMesh mesh1)

Find the polyhedral boundary of the CSG (constructive solid geometry) difference of two meshes, given by

 mesh1 - mesh0
 

The resulting mesh will be empty if mesh1 is entirely inside mesh0.

Parameters:

mesh0 - first intersecting mesh

mesh1 - second intersecting mesh

Returns:

mesh describing the difference boundary.

findMesh0Inside

public PolygonalMesh findMesh0Inside(PolygonalMesh mesh0,
                                     PolygonalMesh mesh1)

Find the polyhedral portion of mesh0 that is inside the intersection region between mesh0 and mesh1. The resulting mesh will be empty if the intersection results in no closed intersection contours.

Parameters:

mesh0 - first intersecting mesh

mesh1 - second intersecting mesh

Returns:

mesh describing the part of mesh0 inside the intersection

findMesh0Outside

public PolygonalMesh findMesh0Outside(PolygonalMesh mesh0,
                                      PolygonalMesh mesh1)

Find the polyhedral portion of mesh0 that is outside the intersection region between mesh0 and mesh1. The resulting mesh will be empty if the intersection results in no closed intersection contours.

Parameters:

mesh0 - first intersecting mesh

mesh1 - second intersecting mesh

Returns:

mesh describing the part of mesh0 outside the intersection

findMesh1Inside

public PolygonalMesh findMesh1Inside(PolygonalMesh mesh0,
                                     PolygonalMesh mesh1)

Find the polyhedral portion of mesh1 that is inside the intersection region between mesh0 and mesh1. The resulting mesh will be empty if the intersection results in no closed intersection contours.

Parameters:

mesh0 - first intersecting mesh

mesh1 - second intersecting mesh

Returns:

mesh describing the part of mesh1 inside the intersection

findMesh1Outside

public PolygonalMesh findMesh1Outside(PolygonalMesh mesh0,
                                      PolygonalMesh mesh1)

Find the polyhedral portion of mesh1 that is outside the intersection region between mesh0 and mesh1. The resulting mesh will be empty if the intersection results in no closed intersection contours.

Parameters:

mesh0 - first intersecting mesh

mesh1 - second intersecting mesh

Returns:

mesh describing the part of mesh1 outside the intersection

createCSGMesh

public PolygonalMesh createCSGMesh(ContactInfo cinfo)

Computes the boundary mesh formed by the union of the penetration regions associated with two meshes. The meshes, intersection contours, and penetration regions are described in the supplied ContactInfo object. These meshes and contours must also correspond to those associated with the most recent intersection contours computed by this intersector.

Whether or not the penetration regions for each mesh are "inside" or "outside" the opposite mesh determines the type of CSG volume produced:

mesh0 regions	mesh1 regions	CSG volume
inside	inside	intersection
outside	outside	union
outside	inside	difference (mesh0-mesh1)
inside	outside	difference (mesh1-mesh0)
inside	none	portion of mesh0 inside intersection
outside	none	portion of mesh0 outside intersection
none	inside	portion of mesh1 inside intersection
none	outside	portion of mesh1 outside intersection

Parameters:

cinfo - meshes, contours and penetration regions from which the CSG boundary is to be constructed

Returns:

bounding mesh for resulting CSG volume

Throws:

java.lang.IllegalStateException - if the contours and meshes do not match the contours most recently produced by this intersector

createCSGMeshOld

public PolygonalMesh createCSGMeshOld(ContactInfo cinfo)

findIntersectionContours

public int findIntersectionContours(java.util.ArrayList<IntersectionContour> contours,
                                    Boundable[] elems0,
                                    Boundable[] elems1,
                                    boolean edgeOnMesh0)

Look for intersecting triangles in elems0 and elems1. If a new intersection is found, use this as the starting point for tracing a new intersection contour.

edgeIntersectingFace

public HalfEdge edgeIntersectingFace(Face face,
                                     Face otherFace,
                                     IntersectionContour contour)

addEmptyFaceVertices

public Vertex3d addEmptyFaceVertices(Vertex3dList poly,
                                     HalfEdge edge,
                                     IntersectionPoint emip,
                                     IntersectionPoint xmip,
                                     PenetrationRegion region,
                                     Vertex3d curVtx,
                                     boolean clockwise,
                                     boolean debug)