SimTK::PointContact Class Reference

This subclass of Contact represents a symmetric contact centered at a single point, such as between two spheres or a sphere and a half space. More...

#include <Contact.h>

Inheritance diagram for SimTK::PointContact:

List of all members.

Public Member Functions
	PointContact (ContactSurfaceIndex surf1, ContactSurfaceIndex surf2, Vec3 &location, Vec3 &normal, Real radius1, Real radius2, Real depth)
	Create a PointContact object representing a general (elliptical) contact.
	PointContact (ContactSurfaceIndex surf1, ContactSurfaceIndex surf2, Vec3 &location, Vec3 &normal, Real radius, Real depth)
	Create a PointContact object representing a circularly symmetric contact.
Vec3	getLocation () const
	The location where the two surfaces touch, specified in the ground frame.
Vec3	getNormal () const
	Get the surface normal at the contact location.
Real	getRadiusOfCurvature1 () const
	Get the first principal relative radius of curvature of the contact surface.
Real	getRadiusOfCurvature2 () const
	Get the second principal relative radius of curvature of the contact surface.
Real	getEffectiveRadiusOfCurvature () const
	Get the effective relative radius of curvature of the contact surface.
Real	getDepth () const
	Get the penetration depth.
Static Public Member Functions
static bool	isInstance (const Contact &contact)
	Determine whether a Contact object is a PointContact.
static ContactTypeId	classTypeId ()
	Obtain the unique small-integer id for the PointContact class.

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Detailed Description

This subclass of Contact represents a symmetric contact centered at a single point, such as between two spheres or a sphere and a half space.

It characterizes the contact by the center location and radius of the contact patch, the normal vector, and the penetration depth.

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Constructor & Destructor Documentation

SimTK::PointContact::PointContact	(	ContactSurfaceIndex	surf1,
		ContactSurfaceIndex	surf2,
		Vec3 &	location,
		Vec3 &	normal,
		Real	radius1,
		Real	radius2,
		Real	depth
	)

Create a PointContact object representing a general (elliptical) contact.

Parameters:

surf1	the index of the first surface involved in the contact, specified by its index within its contact set
surf2	the index of the second surface involved in the contact, specified by its index within its contact set
location	the location where the two surfaces touch, specified in the ground frame
normal	the surface normal at the contact location. This is specified in the ground frame, and points outward from surface1 towards surface2
radius1	the first principal relative radius of curvature of the contact surface
radius2	the second principal relative radius of curvature of the contact surface
depth	the penetration depth

SimTK::PointContact::PointContact	(	ContactSurfaceIndex	surf1,
		ContactSurfaceIndex	surf2,
		Vec3 &	location,
		Vec3 &	normal,
		Real	radius,
		Real	depth
	)

Create a PointContact object representing a circularly symmetric contact.

Parameters:

surf1	the index of the first surface involved in the contact, specified by its index within its contact set
surf2	the index of the second surface involved in the contact, specified by its index within its contact set
location	the location where the two surfaces touch, specified in the ground frame
normal	the surface normal at the contact location. This is specified in the ground frame, and points outward from surface1 towards surface2
radius	the relative radius of curvature of the contact surface
depth	the penetration depth

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Member Function Documentation

Vec3 SimTK::PointContact::getLocation

(

)

const

The location where the two surfaces touch, specified in the ground frame.

More precisely, the contact region is represented as a circular patch centered at this point and perpendicular to the normal vector.

Vec3 SimTK::PointContact::getNormal

(

)

const

Get the surface normal at the contact location.

This is specified in the ground frame, and points outward from surface1 towards surface2.

Real SimTK::PointContact::getRadiusOfCurvature1

(

)

const

Get the first principal relative radius of curvature of the contact surface.

Real SimTK::PointContact::getRadiusOfCurvature2

(

)

const

Get the second principal relative radius of curvature of the contact surface.

Real SimTK::PointContact::getEffectiveRadiusOfCurvature

(

)

const

Get the effective relative radius of curvature of the contact surface.

This is equal to sqrt(R1*R2), where R1 and R2 are the principal relative radii of curvature.

Real SimTK::PointContact::getDepth

(

)

const

Get the penetration depth.

This is defined as the minimum distance you would need to translate one surface along the normal vector to make the surfaces no longer overlap.

static bool SimTK::PointContact::isInstance

(

const Contact &

contact

)

[static]

Determine whether a Contact object is a PointContact.

static ContactTypeId SimTK::PointContact::classTypeId

(

)

[static]

Obtain the unique small-integer id for the PointContact class.

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

• Contact.h