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SbRotation Class Reference
[Base classes]

The SbRotation class represents a rotation in 3D space. More...

#include <Inventor/SbLinear.h>

List of all members.

Public Methods

 SbRotation (void)
 SbRotation (const SbVec3f &axis, const float radians)
 SbRotation (const float q[4])
 SbRotation (const float q0, const float q1, const float q2, const float q3)
 SbRotation (const SbMatrix &m)
 SbRotation (const SbVec3f &rotateFrom, const SbVec3f &rotateTo)
const float * getValue (void) const
void getValue (float &q0, float &q1, float &q2, float &q3) const
SbRotation & setValue (const float q0, const float q1, const float q2, const float q3)
void getValue (SbVec3f &axis, float &radians) const
void getValue (SbMatrix &matrix) const
SbRotation & invert (void)
SbRotation inverse (void) const
SbRotation & setValue (const float q[4])
SbRotation & setValue (const SbMatrix &m)
SbRotation & setValue (const SbVec3f &axis, const float radians)
SbRotation & setValue (const SbVec3f &rotateFrom, const SbVec3f &rotateTo)
SbRotation & operator *= (const SbRotation &q)
SbRotation & operator *= (const float s)
SbBool equals (const SbRotation &r, const float tolerance) const
void multVec (const SbVec3f &src, SbVec3f &dst) const
void scaleAngle (const float scaleFactor)
void print (FILE *fp) const

Static Public Methods

SbRotation slerp (const SbRotation &rot0, const SbRotation &rot1, float t)
SbRotation identity (void)

Friends

int operator== (const SbRotation &q1, const SbRotation &q2)
int operator!= (const SbRotation &q1, const SbRotation &q2)
SbRotation operator * (const SbRotation &q1, const SbRotation &q2)


Detailed Description

The SbRotation class represents a rotation in 3D space.

SbRotation is used extensively throughout the Coin library.

An SbRotation is stored internally as a quaternion for speed and storage reasons, but inquiries can be done to get and set axis and angle values for convenience.

Note that there is one very common mistake that is easy to make when setting the value of an SbRotation, and that is to inadvertently use the wrong SbRotation constructor. This example should clarify the problem:

  SbRotation rotation(0, 0, 1, 1.5707963f);

The programmer clearly tries to set a PI/2 rotation around the Z axis, but this will fail, as the SbRotation constructor invoked above is the one that takes as arguments the 4 floats of a quaternion. What the programmer almost certainly wanted to do was to use the SbRotation constructor that takes a rotation vector and a rotation angle, which is invoked like this:

  SbRotation rotation(SbVec3f(0, 0, 1), 1.5707963f);

See also:
SbMatrix


Constructor & Destructor Documentation

SbRotation::SbRotation void   
 

The default constructor just initializes a valid rotation. The actual value is unspecified, and you should not depend on it.

SbRotation::SbRotation const SbVec3f   axis,
const float    radians
 

Construct a new SbRotation object initialized with the given axis-of-rotation and rotation angle.

SbRotation::SbRotation const float    q[4]
 

Construct a new SbRotation object initialized with the given quaternion components.

The array must be ordered as follows:

q[0] = x, q[1] = y, q[2] = z and q[3] = w, where the quaternion is specified by q=w+xi+yj+zk.

SbRotation::SbRotation const float    q0,
const float    q1,
const float    q2,
const float    q3
 

Construct a new SbRotation object initialized with the given quaternion components.

SbRotation::SbRotation const SbMatrix   m
 

Construct a new SbRotation object initialized with the given rotation matrix.

SbRotation::SbRotation const SbVec3f   rotateFrom,
const SbVec3f   rotateTo
 

Construct a rotation which is the minimum rotation necessary to make vector rotateFrom point in the direction of vector rotateTo.


Member Function Documentation

const float * SbRotation::getValue void    const
 

Return pointer to an array with the rotation expressed as four quaternion values.

See also:
setValue().

void SbRotation::getValue float &    q0,
float &    q1,
float &    q2,
float &    q3
const
 

Return the four quaternion components representing the rotation.

See also:
setValue().

SbRotation & SbRotation::setValue const float    q0,
const float    q1,
const float    q2,
const float    q3
 

Set the rotation.

See also:
getValue().

void SbRotation::getValue SbVec3f   axis,
float &    radians
const
 

Return the rotation in the form of an axis-of-rotation and a rotation angle.

See also:
setValue().

void SbRotation::getValue SbMatrix   matrix const
 

Return this rotation in the form of a matrix.

See also:
setValue().

SbRotation & SbRotation::invert void   
 

Invert the rotation. Returns reference to self.

See also:
inverse()

SbRotation SbRotation::inverse void    const
 

Non-destructively inverses the rotation and returns the result.

See also:
invert()

SbRotation & SbRotation::setValue const float    q[4]
 

Reset the rotation by the four quaternions in the array.

See also:
getValue().

SbRotation & SbRotation::setValue const SbMatrix   m
 

Set the rotation from the components of the given matrix. Returns reference to self.

See also:
getValue().

SbRotation & SbRotation::setValue const SbVec3f   axis,
const float    radians
 

Reset rotation with the given axis-of-rotation and rotation angle. Returns reference to self.

Make sure axis is not the null vector when calling this method.

See also:
getValue().

SbRotation & SbRotation::setValue const SbVec3f   rotateFrom,
const SbVec3f   rotateTo
 

Construct a rotation which is the minimum rotation necessary to make vector rotateFrom point in the direction of vector rotateTo.

Returns reference to self.

See also:
getValue().

SbRotation & SbRotation::operator *= const SbRotation &    q
 

Multiplies the quaternions.

Note that order is important when combining quaternions with the multiplication operator.

SbRotation & SbRotation::operator *= const float    s
 

Multiplies components of quaternion with scalar value s. Returns reference to self.

SbBool SbRotation::equals const SbRotation &    r,
const float    tolerance
const
 

Check the internal quaternion representation vectors for equality within the given tolerance.

void SbRotation::multVec const SbVec3f   src,
SbVec3f   dst
const
 

Rotate the src vector and put the result in dst.

void SbRotation::scaleAngle const float    scaleFactor
 

Scale the angle of rotation by scaleFactor.

SbRotation slerp const SbRotation &    rot0,
const SbRotation &    rot1,
float    t
[static]
 

Interpolates along the shortest path between the two rotation positions (from rot0 to rot1).

Returns the SbRotation which will rotate rot0 the given part t of the spherical distance towards rot1, where t=0 will yield rot0 and t=1 will yield rot1.

t should be in the interval [0, 1].

SbRotation SbRotation::identity void    [static]
 

Returns an identity rotation.

void SbRotation::print FILE *    fp const
 

Dump the state of this object to the fp file stream. Only works in debug version of library, method does nothing in an optimized compile.


Friends And Related Function Documentation

int operator== const SbRotation &    q1,
const SbRotation &    q2
[friend]
 

Check if the two rotations are equal.

See also:
equals().

int operator!= const SbRotation &    q1,
const SbRotation &    q2
[friend]
 

Check if the two rotations are unequal.

See also:
equals().

SbRotation operator * const SbRotation &    q1,
const SbRotation &    q2
[friend]
 

Multiplies the two rotations and returns the result.

Note that order is important when combining quaternions with the multiplication operator.


The documentation for this class was generated from the following files:
Generated on Sat May 24 22:39:44 2003 for Coin by doxygen1.2.18