Real Curve3<Real>::GetTorsion ( Real t ) const
{
Vector3<Real> velocity = GetFirstDerivative( t );
Vector3<Real> acceleration = GetSecondDerivative( t );
Vector3<Real> cross = velocity.Cross( acceleration );
Real denom = cross.SquaredLength();
if ( denom >= Math<Real>::ZERO_TOLERANCE )
{
Vector3<Real> jerk = GetThirdDerivative( t );
Real numer = cross.Dot( jerk );
return numer / denom;
}
else
{
// Torsion is indeterminate, just return 0.
return ( Real )0;
}
}
Real Curve<Real>::GetTorsion (Real t)
{
Vector3 velocity = GetFirstDerivative(t);
Vector3 acceleration = GetSecondDerivative(t);
Vector3 _cross = velocity.cross(acceleration);
Real denom = _cross.squaredNorm();
if (denom >= REAL_ZERO_TOLERANCE)
{
Vector3 jerk = GetThirdDerivative(t);
Real numer = dot(_cross,jerk);
return numer/denom;
}
else
{
// Torsion is indeterminate, just return 0.
return (Real)0;
}
}
