public override float CalculateTimeOfImpact(CollisionObject body0,CollisionObject body1,DispatcherInfo dispatchInfo,ManifoldResult resultOut)
{
///Rather then checking ALL pairs, only calculate TOI when motion exceeds threshold
///Linear motion for one of objects needs to exceed m_ccdSquareMotionThreshold
///body0.m_worldTransform,
float resultFraction = 1.0f;
float squareMot0 = (body0.GetInterpolationWorldTransform().Translation - body0.GetWorldTransform().Translation).LengthSquared();
float squareMot1 = (body1.GetInterpolationWorldTransform().Translation - body1.GetWorldTransform().Translation).LengthSquared();
if (squareMot0 < body0.GetCcdSquareMotionThreshold() &&
squareMot1 < body1.GetCcdSquareMotionThreshold())
{
return resultFraction;
}
//An adhoc way of testing the Continuous Collision Detection algorithms
//One object is approximated as a sphere, to simplify things
//Starting in penetration should report no time of impact
//For proper CCD, better accuracy and handling of 'allowed' penetration should be added
//also the mainloop of the physics should have a kind of toi queue (something like Brian Mirtich's application of Timewarp for Rigidbodies)
/// Convex0 against sphere for Convex1
{
ConvexShape convex0 = (ConvexShape)(body0.GetCollisionShape());
SphereShape sphere1 = new SphereShape(body1.GetCcdSweptSphereRadius()); //todo: allow non-zero sphere sizes, for better approximation
CastResult result = new CastResult();
VoronoiSimplexSolver voronoiSimplex = new VoronoiSimplexSolver();
//SubsimplexConvexCast ccd0(&sphere,min0,&voronoiSimplex);
///Simplification, one object is simplified as a sphere
GjkConvexCast ccd1 = new GjkConvexCast( convex0 ,sphere1,voronoiSimplex);
//ContinuousConvexCollision ccd(min0,min1,&voronoiSimplex,0);
if (ccd1.CalcTimeOfImpact(body0.GetWorldTransform(),body0.GetInterpolationWorldTransform(),
body1.GetWorldTransform(),body1.GetInterpolationWorldTransform(),result))
{
//store result.m_fraction in both bodies
if (body0.GetHitFraction()> result.m_fraction)
{
body0.SetHitFraction( result.m_fraction );
}
if (body1.GetHitFraction() > result.m_fraction)
{
body1.SetHitFraction( result.m_fraction);
}
if (resultFraction > result.m_fraction)
{
resultFraction = result.m_fraction;
}
}
}
/// Sphere (for convex0) against Convex1
{
ConvexShape convex1 = (ConvexShape)(body1.GetCollisionShape());
SphereShape sphere0 = new SphereShape(body0.GetCcdSweptSphereRadius()); //todo: allow non-zero sphere sizes, for better approximation
CastResult result = new CastResult();
VoronoiSimplexSolver voronoiSimplex = new VoronoiSimplexSolver();
//SubsimplexConvexCast ccd0(&sphere,min0,&voronoiSimplex);
///Simplification, one object is simplified as a sphere
GjkConvexCast ccd1 = new GjkConvexCast(sphere0,convex1,voronoiSimplex);
//ContinuousConvexCollision ccd(min0,min1,&voronoiSimplex,0);
if (ccd1.CalcTimeOfImpact(body0.GetWorldTransform(),body0.GetInterpolationWorldTransform(),
body1.GetWorldTransform(),body1.GetInterpolationWorldTransform(),result))
{
//store result.m_fraction in both bodies
if (body0.GetHitFraction() > result.m_fraction)
{
body0.SetHitFraction( result.m_fraction);
}
if (body1.GetHitFraction() > result.m_fraction)
{
body1.SetHitFraction( result.m_fraction);
}
if (resultFraction > result.m_fraction)
{
resultFraction = result.m_fraction;
}
}
}
return resultFraction;
}
