Simbody  3.6
SimTK::ContactGeometry::HalfSpace Class Reference

This ContactGeometry subclass represents an object that occupies the entire half-space x>0. More...

+ Inheritance diagram for SimTK::ContactGeometry::HalfSpace:

Public Member Functions

 HalfSpace ()
 Create a HalfSpace for contact, with surface passing through the origin and outward normal -XAxis (in its own frame). More...
 
UnitVec3 getNormal () const
 Return the HalfSpace outward normal in its own frame as a unit vector. More...
 
const Impl & getImpl () const
 Internal use only. More...
 
Impl & updImpl ()
 Internal use only. More...
 
- Public Member Functions inherited from SimTK::ContactGeometry
 ContactGeometry ()
 Base class default constructor creates an empty handle. More...
 
 ContactGeometry (const ContactGeometry &src)
 Copy constructor makes a deep copy. More...
 
ContactGeometryoperator= (const ContactGeometry &src)
 Copy assignment makes a deep copy. More...
 
 ~ContactGeometry ()
 Base class destructor deletes the implementation object. Note that this is not virtual; handles should consist of just a pointer to the implementation. More...
 
DecorativeGeometry createDecorativeGeometry () const
 Generate a DecorativeGeometry that matches the shape of this ContactGeometry. More...
 
Vec3 findNearestPoint (const Vec3 &position, bool &inside, UnitVec3 &normal) const
 Given a point, find the nearest point on the surface of this object. More...
 
Vec3 projectDownhillToNearestPoint (const Vec3 &pointQ) const
 Given a query point Q, find the nearest point P on the surface of this object, looking only down the local gradient. More...
 
bool trackSeparationFromLine (const Vec3 &pointOnLine, const UnitVec3 &directionOfLine, const Vec3 &startingGuessForClosestPoint, Vec3 &newClosestPointOnSurface, Vec3 &closestPointOnLine, Real &height) const
 Track the closest point between this implicit surface and a given line, or the point of deepest penetration if the line intersects the surface. More...
 
bool intersectsRay (const Vec3 &origin, const UnitVec3 &direction, Real &distance, UnitVec3 &normal) const
 Determine whether this object intersects a ray, and if so, find the intersection point. More...
 
void getBoundingSphere (Vec3 &center, Real &radius) const
 Get a bounding sphere which completely encloses this object. More...
 
bool isSmooth () const
 Returns true if this is a smooth surface, meaning that it can provide meaningful curvature information and continuous derivatives with respect to its parameterization. More...
 
void calcCurvature (const Vec3 &point, Vec2 &curvature, Rotation &orientation) const
 Compute the principal curvatures and their directions, and the surface normal, at a given point on a smooth surface. More...
 
const FunctiongetImplicitFunction () const
 Our smooth surfaces define a function f(P)=0 that provides an implicit representation of the surface. More...
 
Real calcSurfaceValue (const Vec3 &point) const
 Calculate the value of the implicit surface function, at a given point. More...
 
UnitVec3 calcSurfaceUnitNormal (const Vec3 &point) const
 Calculate the implicit surface outward facing unit normal at the given point. More...
 
Vec3 calcSurfaceGradient (const Vec3 &point) const
 Calculate the gradient of the implicit surface function, at a given point. More...
 
Mat33 calcSurfaceHessian (const Vec3 &point) const
 Calculate the hessian of the implicit surface function, at a given point. More...
 
Real calcGaussianCurvature (const Vec3 &gradient, const Mat33 &Hessian) const
 For an implicit surface, return the Gaussian curvature at the point p whose implicit surface function gradient g(p) and Hessian H(p) are supplied. More...
 
Real calcGaussianCurvature (const Vec3 &point) const
 This signature is for convenience; use the other one to save time if you already have the gradient and Hessian available for this point. More...
 
Real calcSurfaceCurvatureInDirection (const Vec3 &point, const UnitVec3 &direction) const
 For an implicit surface, return the curvature k of the surface at a given point p in a given direction tp. More...
 
void calcSurfacePrincipalCurvatures (const Vec3 &point, Vec2 &curvature, Rotation &R_SP) const
 For an implicit surface at a given point p, return the principal curvatures and principal curvature directions, using only the implicit function and its derivatives. More...
 
bool isConvex () const
 Returns true if this surface is known to be convex. More...
 
Vec3 calcSupportPoint (UnitVec3 direction) const
 Given a direction expressed in the surface's frame S, return the point P on the surface that is the furthest in that direction (or one of those points if there is more than one). More...
 
ContactGeometryTypeId getTypeId () const
 ContactTrackerSubsystem uses this id for fast identification of specific surface shapes. More...
 
 ContactGeometry (ContactGeometryImpl *impl)
 Internal use only. More...
 
bool isOwnerHandle () const
 Internal use only. More...
 
bool isEmptyHandle () const
 Internal use only. More...
 
bool hasImpl () const
 Internal use only. More...
 
const ContactGeometryImpl & getImpl () const
 Internal use only. More...
 
ContactGeometryImpl & updImpl ()
 Internal use only. More...
 
void initGeodesic (const Vec3 &xP, const Vec3 &xQ, const Vec3 &xSP, const GeodesicOptions &options, Geodesic &geod) const
 Given two points, find a geodesic curve connecting them. More...
 
void continueGeodesic (const Vec3 &xP, const Vec3 &xQ, const Geodesic &prevGeod, const GeodesicOptions &options, Geodesic &geod) const
 Given the current positions of two points P and Q moving on this surface, and the previous geodesic curve G' connecting prior locations P' and Q' of those same two points, return the geodesic G between P and Q that is closest in length to the previous one. More...
 
void makeStraightLineGeodesic (const Vec3 &xP, const Vec3 &xQ, const UnitVec3 &defaultDirectionIfNeeded, const GeodesicOptions &options, Geodesic &geod) const
 Produce a straight-line approximation to the (presumably short) geodesic between two points on this implicit surface. More...
 
void shootGeodesicInDirectionUntilLengthReached (const Vec3 &xP, const UnitVec3 &tP, const Real &terminatingLength, const GeodesicOptions &options, Geodesic &geod) const
 Compute a geodesic curve starting at the given point, starting in the given direction, and terminating at the given length. More...
 
void calcGeodesicReverseSensitivity (Geodesic &geodesic, const Vec2 &initSensitivity=Vec2(0, 1)) const
 Given an already-calculated geodesic on this surface connecting points P and Q, fill in the sensitivity of point P with respect to a change of tangent direction at Q. More...
 
void shootGeodesicInDirectionUntilPlaneHit (const Vec3 &xP, const UnitVec3 &tP, const Plane &terminatingPlane, const GeodesicOptions &options, Geodesic &geod) const
 Compute a geodesic curve starting at the given point, starting in the given direction, and terminating when it hits the given plane. More...
 
void calcGeodesic (const Vec3 &xP, const Vec3 &xQ, const Vec3 &tPhint, const Vec3 &tQhint, Geodesic &geod) const
 Utility method to find geodesic between P and Q using split geodesic method with initial shooting directions tPhint and -tQhint. More...
 
void calcGeodesicUsingOrthogonalMethod (const Vec3 &xP, const Vec3 &xQ, const Vec3 &tPhint, Real lengthHint, Geodesic &geod) const
 Utility method to find geodesic between P and Q using the orthogonal method, with initial direction tPhint and initial length lengthHint. More...
 
void calcGeodesicUsingOrthogonalMethod (const Vec3 &xP, const Vec3 &xQ, Geodesic &geod) const
 This signature makes a guess at the initial direction and length and then calls the other signature. More...
 
Vec2 calcSplitGeodError (const Vec3 &P, const Vec3 &Q, const UnitVec3 &tP, const UnitVec3 &tQ, Geodesic *geod=0) const
 Utility method to calculate the "geodesic error" between one geodesic shot from P in the direction tP and another geodesic shot from Q in the direction tQ. More...
 
void shootGeodesicInDirectionUntilLengthReachedAnalytical (const Vec3 &xP, const UnitVec3 &tP, const Real &terminatingLength, const GeodesicOptions &options, Geodesic &geod) const
 Analytically compute a geodesic curve starting at the given point, starting in the given direction, and terminating at the given length. More...
 
void shootGeodesicInDirectionUntilPlaneHitAnalytical (const Vec3 &xP, const UnitVec3 &tP, const Plane &terminatingPlane, const GeodesicOptions &options, Geodesic &geod) const
 Analytically compute a geodesic curve starting at the given point, starting in the given direction, and terminating when it hits the given plane. More...
 
void calcGeodesicAnalytical (const Vec3 &xP, const Vec3 &xQ, const Vec3 &tPhint, const Vec3 &tQhint, Geodesic &geod) const
 Utility method to analytically find geodesic between P and Q with initial shooting directions tPhint and tQhint. More...
 
Vec2 calcSplitGeodErrorAnalytical (const Vec3 &P, const Vec3 &Q, const UnitVec3 &tP, const UnitVec3 &tQ, Geodesic *geod=0) const
 Utility method to analytically calculate the "geodesic error" between one geodesic shot from P in the direction tP and another geodesic shot from Q in the direction tQ. More...
 
const PlanegetPlane () const
 Get the plane associated with the geodesic hit plane event handler. More...
 
void setPlane (const Plane &plane) const
 Set the plane associated with the geodesic hit plane event handler. More...
 
const GeodesicgetGeodP () const
 Get the geodesic for access by visualizer. More...
 
const GeodesicgetGeodQ () const
 Get the geodesic for access by visualizer. More...
 
const int getNumGeodesicsShot () const
 Get the plane associated with the geodesic hit plane event handler. More...
 
void addVizReporter (ScheduledEventReporter *reporter) const
 Get the plane associated with the geodesic hit plane event handler. More...
 

Static Public Member Functions

static bool isInstance (const ContactGeometry &geo)
 Return true if the supplied ContactGeometry object is a halfspace. More...
 
static const HalfSpacegetAs (const ContactGeometry &geo)
 Cast the supplied ContactGeometry object to a const halfspace. More...
 
static HalfSpaceupdAs (ContactGeometry &geo)
 Cast the supplied ContactGeometry object to a writable halfspace. More...
 
static ContactGeometryTypeId classTypeId ()
 Obtain the unique id for HalfSpace contact geometry. More...
 
- Static Public Member Functions inherited from SimTK::ContactGeometry
static Vec2 evalParametricCurvature (const Vec3 &P, const UnitVec3 &nn, const Vec3 &dPdu, const Vec3 &dPdv, const Vec3 &d2Pdu2, const Vec3 &d2Pdv2, const Vec3 &d2Pdudv, Transform &X_EP)
 Calculate surface curvature at a point using differential geometry as suggested by Harris 2006, "Curvature of ellipsoids and other surfaces" Ophthal. More...
 
static void combineParaboloids (const Rotation &R_SP1, const Vec2 &k1, const UnitVec3 &x2, const Vec2 &k2, Rotation &R_SP, Vec2 &k)
 This utility method is useful for characterizing the relative geometry of two locally-smooth surfaces in contact, in a way that is useful for later application of Hertz compliant contact theory for generating forces. More...
 
static void combineParaboloids (const Rotation &R_SP1, const Vec2 &k1, const UnitVec3 &x2, const Vec2 &k2, Vec2 &k)
 This is a much faster version of combineParaboloids() for when you just need the curvatures of the difference paraboloid, but not the directions of those curvatures. More...
 

Additional Inherited Members

- Protected Attributes inherited from SimTK::ContactGeometry
ContactGeometryImpl * impl
 Internal use only. More...
 

Detailed Description

This ContactGeometry subclass represents an object that occupies the entire half-space x>0.

This is useful for representing walls and floors. This object has infinite extent.

Constructor & Destructor Documentation

◆ HalfSpace()

Create a HalfSpace for contact, with surface passing through the origin and outward normal -XAxis (in its own frame).

Thus the half-space is all of x>0. When this is placed on a Body, a Transform is provided that repositions the half-space to the desired location and orientation in the Body's frame.

Member Function Documentation

◆ getNormal()

UnitVec3 SimTK::ContactGeometry::HalfSpace::getNormal ( ) const

Return the HalfSpace outward normal in its own frame as a unit vector.

◆ isInstance()

static bool SimTK::ContactGeometry::HalfSpace::isInstance ( const ContactGeometry geo)
inlinestatic

Return true if the supplied ContactGeometry object is a halfspace.

◆ getAs()

static const HalfSpace& SimTK::ContactGeometry::HalfSpace::getAs ( const ContactGeometry geo)
inlinestatic

Cast the supplied ContactGeometry object to a const halfspace.

◆ updAs()

static HalfSpace& SimTK::ContactGeometry::HalfSpace::updAs ( ContactGeometry geo)
inlinestatic

Cast the supplied ContactGeometry object to a writable halfspace.

◆ classTypeId()

static ContactGeometryTypeId SimTK::ContactGeometry::HalfSpace::classTypeId ( )
static

Obtain the unique id for HalfSpace contact geometry.

◆ getImpl()

const Impl& SimTK::ContactGeometry::HalfSpace::getImpl ( ) const

Internal use only.

Internal use only.

◆ updImpl()

Impl& SimTK::ContactGeometry::HalfSpace::updImpl ( )

Internal use only.


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