GJKClosestPoint Class Reference

#include <GJKClosestPoint.h>

Inheritance diagram for GJKClosestPoint:

Public Member Functions
template<typename A , typename B >
bool	Intersects (const A &inA, const B &inB, float inTolerance, Vec3 &ioV)
template<typename A , typename B >
float	GetClosestPoints (const A &inA, const B &inB, float inTolerance, float inMaxDistSq, Vec3 &ioV, Vec3 &outPointA, Vec3 &outPointB)
void	GetClosestPointsSimplex (Vec3 *outY, Vec3 *outP, Vec3 *outQ, uint &outNumPoints) const
template<typename A >
bool	CastRay (Vec3Arg inRayOrigin, Vec3Arg inRayDirection, float inTolerance, const A &inA, float &ioLambda)
template<typename A , typename B >
bool	CastShape (Mat44Arg inStart, Vec3Arg inDirection, float inTolerance, const A &inA, const B &inB, float &ioLambda)
template<typename A , typename B >
bool	CastShape (Mat44Arg inStart, Vec3Arg inDirection, float inTolerance, const A &inA, const B &inB, float inConvexRadiusA, float inConvexRadiusB, float &ioLambda, Vec3 &outPointA, Vec3 &outPointB, Vec3 &outSeparatingAxis)
Public Member Functions inherited from NonCopyable
	NonCopyable ()=default
	NonCopyable (const NonCopyable &)=delete
void	operator= (const NonCopyable &)=delete

Detailed Description

Convex vs convex collision detection Based on: A Fast and Robust GJK Implementation for Collision Detection of Convex Objects - Gino van den Bergen

Member Function Documentation

CastRay()

template<typename A >

bool GJKClosestPoint::CastRay ( Vec3Arg inRayOrigin, Vec3Arg inRayDirection, float inTolerance, const A & inA, float & ioLambda )

inline

Test if a ray inRayOrigin + lambda * inRayDirection for lambda e [0, ioLambda> intersects inA

Code based upon: Ray Casting against General Convex Objects with Application to Continuous Collision Detection - Gino van den Bergen

Parameters

inRayOrigin	Origin of the ray
inRayDirection	Direction of the ray (ioLambda * inDirection determines length)
inTolerance	The minimal distance between the ray and A before it is considered colliding
inA	A convex object that has the GetSupport(Vec3) function
ioLambda	The max fraction along the ray, on output updated with the actual collision fraction.

Returns

true if a hit was found, ioLambda is the solution for lambda.

CastShape() [1/2]

template<typename A , typename B >

bool GJKClosestPoint::CastShape ( Mat44Arg inStart, Vec3Arg inDirection, float inTolerance, const A & inA, const B & inB, float & ioLambda )

inline

Test if a cast shape inA moving from inStart to lambda * inStart.GetTranslation() + inDirection where lambda e [0, ioLambda> intersects inB

Parameters

inStart	Start position and orientation of the convex object
inDirection	Direction of the sweep (ioLambda * inDirection determines length)
inTolerance	The minimal distance between A and B before they are considered colliding
inA	The convex object A, must support the GetSupport(Vec3) function.
inB	The convex object B, must support the GetSupport(Vec3) function.
ioLambda	The max fraction along the sweep, on output updated with the actual collision fraction.

Returns

true if a hit was found, ioLambda is the solution for lambda.

CastShape() [2/2]

template<typename A , typename B >

bool GJKClosestPoint::CastShape ( Mat44Arg inStart, Vec3Arg inDirection, float inTolerance, const A & inA, const B & inB, float inConvexRadiusA, float inConvexRadiusB, float & ioLambda, Vec3 & outPointA, Vec3 & outPointB, Vec3 & outSeparatingAxis )

inline

Test if a cast shape inA moving from inStart to lambda * inStart.GetTranslation() + inDirection where lambda e [0, ioLambda> intersects inB

Parameters

inStart	Start position and orientation of the convex object
inDirection	Direction of the sweep (ioLambda * inDirection determines length)
inTolerance	The minimal distance between A and B before they are considered colliding
inA	The convex object A, must support the GetSupport(Vec3) function.
inB	The convex object B, must support the GetSupport(Vec3) function.
inConvexRadiusA	The convex radius of A, this will be added on all sides to pad A.
inConvexRadiusB	The convex radius of B, this will be added on all sides to pad B.
ioLambda	The max fraction along the sweep, on output updated with the actual collision fraction.
outPointA	is the contact point on A (if outSeparatingAxis is near zero, this may not be not the deepest point)
outPointB	is the contact point on B (if outSeparatingAxis is near zero, this may not be not the deepest point)
outSeparatingAxis	On return this will contain a vector that points from A to B along the smallest distance of separation. The length of this vector indicates the separation of A and B without their convex radius. If it is near zero, the direction may not be accurate as the bodies may overlap when lambda = 0.

Returns

true if a hit was found, ioLambda is the solution for lambda and outPoint and outSeparatingAxis are valid.

GetClosestPoints()

template<typename A , typename B >

float GJKClosestPoint::GetClosestPoints ( const A & inA, const B & inB, float inTolerance, float inMaxDistSq, Vec3 & ioV, Vec3 & outPointA, Vec3 & outPointB )

inline

Get closest points between inA and inB

Parameters

inA	The convex object A, must support the GetSupport(Vec3) function.
inB	The convex object B, must support the GetSupport(Vec3) function.
inTolerance	The minimal distance between A and B before the objects are considered colliding and processing is terminated.
inMaxDistSq	The maximum squared distance between A and B before the objects are considered infinitely far away and processing is terminated.
ioV	Initial guess for the separating axis. Start with any non-zero vector if you don't know. If return value is 0, ioV = (0, 0, 0). If the return value is bigger than 0 but smaller than FLT_MAX, ioV will be the separating axis in the direction from A to B and its length the squared distance between A and B. If the return value is FLT_MAX, ioV will be the separating axis in the direction from A to B and the magnitude of the vector is meaningless.
outPointA,outPointB	If the return value is 0 the points are invalid. If the return value is bigger than 0 but smaller than FLT_MAX these will contain the closest point on A and B. If the return value is FLT_MAX the points are invalid.

Returns

The squared distance between A and B or FLT_MAX when they are further away than inMaxDistSq.

GetClosestPointsSimplex()

void GJKClosestPoint::GetClosestPointsSimplex ( Vec3 * outY, Vec3 * outP, Vec3 * outQ, uint & outNumPoints ) const

inline

Get the resulting simplex after the GetClosestPoints algorithm finishes. If it returned a squared distance of 0, the origin will be contained in the simplex.

Intersects()

template<typename A , typename B >

bool GJKClosestPoint::Intersects ( const A & inA, const B & inB, float inTolerance, Vec3 & ioV )

inline

Test if inA and inB intersect

Parameters

inA	The convex object A, must support the GetSupport(Vec3) function.
inB	The convex object B, must support the GetSupport(Vec3) function.
inTolerance	Minimal distance between objects when the objects are considered to be colliding
ioV	is used as initial separating axis (provide a zero vector if you don't know yet)

Returns

True if they intersect (in which case ioV = (0, 0, 0)). False if they don't intersect in which case ioV is a separating axis in the direction from A to B (magnitude is meaningless)

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

• Jolt/Geometry/GJKClosestPoint.h