work on rotations in the Geometry module:

- convertions are done trough constructors and operator=
 - added a EulerAngles class
This commit is contained in:
Gael Guennebaud
2008-06-21 15:01:49 +00:00
parent 574416b842
commit 32c5ea388e
8 changed files with 491 additions and 288 deletions

View File

@@ -25,6 +25,11 @@
#ifndef EIGEN_QUATERNION_H
#define EIGEN_QUATERNION_H
template<typename Other,
int OtherRows=Other::RowsAtCompileTime,
int OtherCols=Other::ColsAtCompileTime>
struct ei_quaternion_assign_impl;
/** \class Quaternion
*
* \brief The quaternion class used to represent 3D orientations and rotations
@@ -39,6 +44,7 @@
* - efficient to compose (28 flops),
* - stable spherical interpolation
*
* \sa class AngleAxis, class EulerAngles, class Transform
*/
template<typename _Scalar>
class Quaternion
@@ -53,6 +59,8 @@ public:
typedef Matrix<Scalar,3,1> Vector3;
typedef Matrix<Scalar,3,3> Matrix3;
typedef AngleAxis<Scalar> AngleAxisType;
typedef EulerAngles<Scalar> EulerAnglesType;
inline Scalar x() const { return m_coeffs.coeff(0); }
inline Scalar y() const { return m_coeffs.coeff(1); }
@@ -71,10 +79,10 @@ public:
inline Block<Coefficients,3,1> vec() { return m_coeffs.template start<3>(); }
/** \returns a read-only vector expression of the coefficients */
inline const Coefficients& _coeffs() const { return m_coeffs; }
inline const Coefficients& coeffs() const { return m_coeffs; }
/** \returns a vector expression of the coefficients */
inline Coefficients& _coeffs() { return m_coeffs; }
inline Coefficients& coeffs() { return m_coeffs; }
// FIXME what is the prefered order: w x,y,z or x,y,z,w ?
inline Quaternion(Scalar w = 1.0, Scalar x = 0.0, Scalar y = 0.0, Scalar z = 0.0)
@@ -88,14 +96,16 @@ public:
/** Copy constructor */
inline Quaternion(const Quaternion& other) { m_coeffs = other.m_coeffs; }
/** This is a special case of the templated operator=. Its purpose is to
* prevent a default operator= from hiding the templated operator=.
*/
inline Quaternion& operator=(const Quaternion& other)
{
m_coeffs = other.m_coeffs;
return *this;
}
explicit inline Quaternion(const AngleAxisType& aa) { *this = aa; }
explicit inline Quaternion(const EulerAnglesType& ea) { *this = ea; }
template<typename Derived>
explicit inline Quaternion(const MatrixBase<Derived>& other) { *this = other; }
Quaternion& operator=(const Quaternion& other);
Quaternion& operator=(const AngleAxisType& aa);
Quaternion& operator=(EulerAnglesType ea);
template<typename Derived>
Quaternion& operator=(const MatrixBase<Derived>& m);
/** \returns a quaternion representing an identity rotation
* \sa MatrixBase::identity()
@@ -116,20 +126,10 @@ public:
*/
inline Scalar norm() const { return m_coeffs.norm(); }
template<typename Derived>
Quaternion& fromRotationMatrix(const MatrixBase<Derived>& m);
Matrix3 toRotationMatrix(void) const;
template<typename Derived>
Quaternion& fromAngleAxis (const Scalar& angle, const MatrixBase<Derived>& axis);
void toAngleAxis(Scalar& angle, Vector3& axis) const;
Quaternion& fromEulerAngles(Vector3 eulerAngles);
Vector3 toEulerAngles(void) const;
template<typename Derived1, typename Derived2>
Quaternion& fromTwoVectors(const MatrixBase<Derived1>& a, const MatrixBase<Derived2>& b);
Quaternion& setFromTwoVectors(const MatrixBase<Derived1>& a, const MatrixBase<Derived2>& b);
inline Quaternion operator* (const Quaternion& q) const;
inline Quaternion& operator*= (const Quaternion& q);
@@ -142,24 +142,6 @@ public:
template<typename Derived>
Vector3 operator* (const MatrixBase<Derived>& vec) const;
protected:
/** Constructor copying the value of the expression \a other */
template<typename OtherDerived>
inline Quaternion(const Eigen::MatrixBase<OtherDerived>& other)
{
m_coeffs = other;
}
/** Copies the value of the expression \a other into \c *this.
*/
template<typename OtherDerived>
inline Quaternion& operator=(const MatrixBase<OtherDerived>& other)
{
m_coeffs = other.derived();
return *this;
}
};
/** \returns the concatenation of two rotations as a quaternion-quaternion product */
@@ -203,16 +185,71 @@ Quaternion<Scalar>::operator* (const MatrixBase<Derived>& v) const
return v + this->w() * uv + this->vec().cross(uv);
}
template<typename Scalar>
inline Quaternion<Scalar>& Quaternion<Scalar>::operator=(const Quaternion& other)
{
m_coeffs = other.m_coeffs;
return *this;
}
/** Set \c *this from an angle-axis \a aa
* and returns a reference to \c *this
*/
template<typename Scalar>
inline Quaternion<Scalar>& Quaternion<Scalar>::operator=(const AngleAxisType& aa)
{
Scalar ha = 0.5*aa.angle();
this->w() = ei_cos(ha);
this->vec() = ei_sin(ha) * aa.axis();
return *this;
}
/** Set \c *this from the rotation defined by the Euler angles \a ea,
* and returns a reference to \c *this
*/
template<typename Scalar>
inline Quaternion<Scalar>& Quaternion<Scalar>::operator=(EulerAnglesType ea)
{
ea.coeffs() *= 0.5;
Vector3 cosines = ea.coeffs().cwiseCos();
Vector3 sines = ea.coeffs().cwiseSin();
Scalar cYcZ = cosines.y() * cosines.z();
Scalar sYsZ = sines.y() * sines.z();
Scalar sYcZ = sines.y() * cosines.z();
Scalar cYsZ = cosines.y() * sines.z();
this->w() = cosines.x() * cYcZ + sines.x() * sYsZ;
this->x() = sines.x() * cYcZ - cosines.x() * sYsZ;
this->y() = cosines.x() * sYcZ + sines.x() * cYsZ;
this->z() = cosines.x() * cYsZ - sines.x() * sYcZ;
return *this;
}
/** Set \c *this from the expression \a xpr:
* - if \a xpr is a 4x1 vector, then \a xpr is assumed to be a quaternion
* - if \a xpr is a 3x3 matrix, then \a xpr is assumed to be rotation matrix
* and \a xpr is converted to a quaternion
*/
template<typename Scalar>
template<typename Derived>
inline Quaternion<Scalar>& Quaternion<Scalar>::operator=(const MatrixBase<Derived>& xpr)
{
ei_quaternion_assign_impl<Derived>::run(*this, xpr.derived());
return *this;
}
/** Convert the quaternion to a 3x3 rotation matrix */
template<typename Scalar>
inline typename Quaternion<Scalar>::Matrix3
Quaternion<Scalar>::toRotationMatrix(void) const
{
// FIXME another option would be to declare toRotationMatrix like that:
// OtherDerived& toRotationMatrix(MatrixBase<OtherDerived>& m)
// it would fill m and returns a ref to m.
// the advantages is that way we can accept 4x4 and 3x4 matrices filling the rest of the
// matrix with I... ??
// NOTE if inlined, then gcc 4.2 and 4.4 get rid of the temporary (not gcc 4.3 !!)
// if not inlined then the cost of the return by value is huge ~ +35%,
// however, not inlining this function is an order of magnitude slower, so
// it has to be inlined, and so the return by value is not an issue
Matrix3 res;
Scalar tx = 2*this->x();
@@ -241,132 +278,13 @@ Quaternion<Scalar>::toRotationMatrix(void) const
return res;
}
/** updates \c *this from the rotation matrix \a m and returns a reference to \c *this
* \warning the size of the input matrix expression \a m must be 3x3 at compile time
*/
template<typename Scalar>
template<typename Derived>
Quaternion<Scalar>& Quaternion<Scalar>::fromRotationMatrix(const MatrixBase<Derived>& mat)
{
// FIXME maybe this function could accept 4x4 and 3x4 matrices as well ? (simply update the assert)
// FIXME this function could also be static and returns a temporary ?
EIGEN_STATIC_ASSERT(Derived::RowsAtCompileTime==3 && Derived::ColsAtCompileTime==3,you_did_a_programming_error);
// This algorithm comes from "Quaternion Calculus and Fast Animation",
// Ken Shoemake, 1987 SIGGRAPH course notes
Scalar t = mat.trace();
if (t > 0)
{
t = ei_sqrt(t + 1.0);
this->w() = 0.5*t;
t = 0.5/t;
this->x() = (mat.coeff(2,1) - mat.coeff(1,2)) * t;
this->y() = (mat.coeff(0,2) - mat.coeff(2,0)) * t;
this->z() = (mat.coeff(1,0) - mat.coeff(0,1)) * t;
}
else
{
int i = 0;
if (mat.coeff(1,1) > mat.coeff(0,0))
i = 1;
if (mat.coeff(2,2) > mat.coeff(i,i))
i = 2;
int j = (i+1)%3;
int k = (j+1)%3;
t = ei_sqrt(mat.coeff(i,i)-mat.coeff(j,j)-mat.coeff(k,k) + 1.0);
m_coeffs.coeffRef(i) = 0.5 * t;
t = 0.5/t;
this->w() = (mat.coeff(k,j)-mat.coeff(j,k))*t;
m_coeffs.coeffRef(j) = (mat.coeff(j,i)+mat.coeff(i,j))*t;
m_coeffs.coeffRef(k) = (mat.coeff(k,i)+mat.coeff(i,k))*t;
}
return *this;
}
/** updates \c *this from the rotation defined by axis \a axis and angle \a angle
* and returns a reference to \c *this
* \warning the size of the input vector expression \a axis must be 3 at compile time
*/
template<typename Scalar>
template<typename Derived>
inline Quaternion<Scalar>& Quaternion<Scalar>
::fromAngleAxis(const Scalar& angle, const MatrixBase<Derived>& axis)
{
ei_assert(Derived::SizeAtCompileTime==3);
Scalar ha = 0.5*angle;
this->w() = ei_cos(ha);
this->vec() = ei_sin(ha) * axis;
return *this;
}
/** Computes and returns the angle and axis of the rotation represented by the quaternion.
* The values are returned in the arguments \a angle and \a axis respectively.
* The returned axis is normalized.
*/
template <typename Scalar>
void Quaternion<Scalar>::toAngleAxis(Scalar& angle, Vector3& axis) const
{
// FIXME should we split this function to an "angle" and an "axis" functions ?
// the drawbacks is that this approach would require to compute twice the norm of (x,y,z)...
// or we returns a Vector4, or a small AngleAxis object... ???
Scalar n2 = this->vec().norm2();
if (ei_isMuchSmallerThan(n2,Scalar(1)))
{
angle = 0;
axis << 1, 0, 0;
}
else
{
angle = 2*std::acos(this->w());
axis = this->vec() / ei_sqrt(n2);
}
}
/** updates \c *this from the rotation defined by the Euler angles \a eulerAngles,
* and returns a reference to \c *this
*/
template <typename Scalar>
Quaternion<Scalar>& Quaternion<Scalar>::fromEulerAngles(Vector3 eulerAngles)
{
// FIXME should the arguments be 3 scalars or a single Vector3 ?
eulerAngles *= 0.5;
Vector3 cosines = eulerAngles.cwiseCos();
Vector3 sines = eulerAngles.cwiseSin();
Scalar cYcZ = cosines.y() * cosines.z();
Scalar sYsZ = sines.y() * sines.z();
Scalar sYcZ = sines.y() * cosines.z();
Scalar cYsZ = cosines.y() * sines.z();
this->w() = cosines.x() * cYcZ + sines.x() * sYsZ;
this->x() = sines.x() * cYcZ - cosines.x() * sYsZ;
this->y() = cosines.x() * sYcZ + sines.x() * cYsZ;
this->z() = cosines.x() * cYsZ - sines.x() * sYcZ;
return *this;
}
/** Computes and returns the Euler angles corresponding to the quaternion \c *this.
*/
template <typename Scalar>
typename Quaternion<Scalar>::Vector3 Quaternion<Scalar>::toEulerAngles(void) const
{
Scalar y2 = this->y() * this->y();
return Vector3(
std::atan2(2*(this->w()*this->x() + this->y()*this->z()), (1 - 2*(this->x()*this->x() + y2))),
std::asin( 2*(this->w()*this->y() - this->z()*this->x())),
std::atan2(2*(this->w()*this->z() + this->x()*this->y()), (1 - 2*(y2 + this->z()*this->z()))));
}
/** Makes a quaternion representing the rotation between two vectors \a a and \a b.
* \returns a reference to the actual quaternion
* Note that the two input vectors have \b not to be normalized.
*/
template<typename Scalar>
template<typename Derived1, typename Derived2>
inline Quaternion<Scalar>& Quaternion<Scalar>::fromTwoVectors(const MatrixBase<Derived1>& a, const MatrixBase<Derived2>& b)
inline Quaternion<Scalar>& Quaternion<Scalar>::setFromTwoVectors(const MatrixBase<Derived1>& a, const MatrixBase<Derived2>& b)
{
Vector3 v0 = a.normalized();
Vector3 v1 = b.normalized();
@@ -399,11 +317,11 @@ inline Quaternion<Scalar> Quaternion<Scalar>::inverse() const
// FIXME should this funtion be called multiplicativeInverse and conjugate() be called inverse() or opposite() ??
Scalar n2 = this->norm2();
if (n2 > 0)
return conjugate()._coeffs() / n2;
return Quaternion(conjugate().coeffs() / n2);
else
{
// return an invalid result to flag the error
return Coefficients::zero();
return Quaternion(Coefficients::zero());
}
}
@@ -448,4 +366,54 @@ Quaternion<Scalar> Quaternion<Scalar>::slerp(Scalar t, const Quaternion& other)
return scale0 * (*this) + scale1 * other;
}
// set from a rotation matrix
template<typename Other>
struct ei_quaternion_assign_impl<Other,3,3>
{
typedef typename Other::Scalar Scalar;
inline static void run(Quaternion<Scalar>& q, const Other& mat)
{
// This algorithm comes from "Quaternion Calculus and Fast Animation",
// Ken Shoemake, 1987 SIGGRAPH course notes
Scalar t = mat.trace();
if (t > 0)
{
t = ei_sqrt(t + 1.0);
q.w() = 0.5*t;
t = 0.5/t;
q.x() = (mat.coeff(2,1) - mat.coeff(1,2)) * t;
q.y() = (mat.coeff(0,2) - mat.coeff(2,0)) * t;
q.z() = (mat.coeff(1,0) - mat.coeff(0,1)) * t;
}
else
{
int i = 0;
if (mat.coeff(1,1) > mat.coeff(0,0))
i = 1;
if (mat.coeff(2,2) > mat.coeff(i,i))
i = 2;
int j = (i+1)%3;
int k = (j+1)%3;
t = ei_sqrt(mat.coeff(i,i)-mat.coeff(j,j)-mat.coeff(k,k) + 1.0);
q.coeffs().coeffRef(i) = 0.5 * t;
t = 0.5/t;
q.w() = (mat.coeff(k,j)-mat.coeff(j,k))*t;
q.coeffs().coeffRef(j) = (mat.coeff(j,i)+mat.coeff(i,j))*t;
q.coeffs().coeffRef(k) = (mat.coeff(k,i)+mat.coeff(i,k))*t;
}
}
};
// set from a vector of coefficients assumed to be a quaternion
template<typename Other>
struct ei_quaternion_assign_impl<Other,4,1>
{
typedef typename Other::Scalar Scalar;
inline static void run(Quaternion<Scalar>& q, const Other& vec)
{
q.coeffs() = vec;
}
};
#endif // EIGEN_QUATERNION_H