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vtkQuaternionInterpolator Class Reference

interpolate a quaternion More...

#include <vtkQuaternionInterpolator.h>

Inherits vtkObject.

Public Types

typedef vtkObject Superclass
 
enum  { INTERPOLATION_TYPE_LINEAR =0, INTERPOLATION_TYPE_SPLINE }
 

Public Member Functions

virtual int IsA (const char *type)
 
vtkQuaternionInterpolatorNewInstance () const
 
void PrintSelf (ostream &os, vtkIndent indent)
 
int GetNumberOfQuaternions ()
 
void Initialize ()
 
void RemoveQuaternion (double t)
 
double GetMinimumT ()
 
double GetMaximumT ()
 
void AddQuaternion (double t, const vtkQuaterniond &q)
 
void AddQuaternion (double t, double q[4])
 
void InterpolateQuaternion (double t, vtkQuaterniond &q)
 
void InterpolateQuaternion (double t, double q[4])
 
virtual void SetInterpolationType (int)
 
virtual int GetInterpolationType ()
 
void SetInterpolationTypeToLinear ()
 
void SetInterpolationTypeToSpline ()
 

Static Public Member Functions

static int IsTypeOf (const char *type)
 
static vtkQuaternionInterpolatorSafeDownCast (vtkObjectBase *o)
 
static vtkQuaternionInterpolatorNew ()
 

Protected Member Functions

virtual vtkObjectBase * NewInstanceInternal () const
 
 vtkQuaternionInterpolator ()
 
virtual ~vtkQuaternionInterpolator ()
 

Protected Attributes

int InterpolationType
 
vtkQuaternionList * QuaternionList
 

Detailed Description

interpolate a quaternion

This class is used to interpolate a series of quaternions representing the rotations of a 3D object. The interpolation may be linear in form (using spherical linear interpolation SLERP), or via spline interpolation (using SQUAD). In either case the interpolation is specialized to quaternions since the interpolation occurs on the surface of the unit quaternion sphere.

To use this class, specify at least two pairs of (t,q[4]) with the AddQuaternion() method. Next interpolate the tuples with the InterpolateQuaternion(t,q[4]) method, where "t" must be in the range of (t_min,t_max) parameter values specified by the AddQuaternion() method (t is clamped otherwise), and q[4] is filled in by the method.

There are several important background references. Ken Shoemake described the practical application of quaternions for the interpolation of rotation (K. Shoemake, "Animating rotation with quaternion curves", Computer Graphics (Siggraph '85) 19(3):245–254, 1985). Another fine reference (available on-line) is E. B. Dam, M. Koch, and M. Lillholm, Technical Report DIKU-TR-98/5, Dept. of Computer Science, University of Copenhagen, Denmark.

Warning
Note that for two or less quaternions, Slerp (linear) interpolation is performed even if spline interpolation is requested. Also, the tangents to the first and last segments of spline interpolation are (arbitrarily) defined by repeating the first and last quaternions.
There are several methods particular to quaternions (norms, products, etc.) implemented interior to this class. These may be moved to a separate quaternion class at some point.
See Also
vtkQuaternion

Definition at line 63 of file vtkQuaternionInterpolator.h.

Member Typedef Documentation

Definition at line 66 of file vtkQuaternionInterpolator.h.

Member Enumeration Documentation

anonymous enum

Enums to control the type of interpolation to use.

Enumerator
INTERPOLATION_TYPE_LINEAR 
INTERPOLATION_TYPE_SPLINE 

Definition at line 113 of file vtkQuaternionInterpolator.h.

Constructor & Destructor Documentation

vtkQuaternionInterpolator::vtkQuaternionInterpolator ( )
protected
virtual vtkQuaternionInterpolator::~vtkQuaternionInterpolator ( )
protectedvirtual

Member Function Documentation

static int vtkQuaternionInterpolator::IsTypeOf ( const char *  type)
static
virtual int vtkQuaternionInterpolator::IsA ( const char *  type)
virtual
static vtkQuaternionInterpolator* vtkQuaternionInterpolator::SafeDownCast ( vtkObjectBase *  o)
static
virtual vtkObjectBase* vtkQuaternionInterpolator::NewInstanceInternal ( ) const
protectedvirtual
vtkQuaternionInterpolator* vtkQuaternionInterpolator::NewInstance ( ) const
void vtkQuaternionInterpolator::PrintSelf ( ostream &  os,
vtkIndent  indent 
)
static vtkQuaternionInterpolator* vtkQuaternionInterpolator::New ( )
static

Instantiate the class.

int vtkQuaternionInterpolator::GetNumberOfQuaternions ( )

Return the number of quaternions in the list of quaternions to be interpolated.

double vtkQuaternionInterpolator::GetMinimumT ( )

Obtain some information about the interpolation range. The numbers returned (corresponding to parameter t, usually thought of as time) are undefined if the list of transforms is empty. This is a convenience method for interpolation.

double vtkQuaternionInterpolator::GetMaximumT ( )

Obtain some information about the interpolation range. The numbers returned (corresponding to parameter t, usually thought of as time) are undefined if the list of transforms is empty. This is a convenience method for interpolation.

void vtkQuaternionInterpolator::Initialize ( )

Reset the class so that it contains no data; i.e., the array of (t,q[4]) information is discarded.

void vtkQuaternionInterpolator::AddQuaternion ( double  t,
const vtkQuaterniond q 
)

Add another quaternion to the list of quaternions to be interpolated. Note that using the same time t value more than once replaces the previous quaternion at t. At least one quaternions must be added to define an interpolation functios.

void vtkQuaternionInterpolator::AddQuaternion ( double  t,
double  q[4] 
)

Add another quaternion to the list of quaternions to be interpolated. Note that using the same time t value more than once replaces the previous quaternion at t. At least one quaternions must be added to define an interpolation functios.

void vtkQuaternionInterpolator::RemoveQuaternion ( double  t)

Delete the quaternion at a particular parameter t. If there is no quaternion tuple defined at t, then the method does nothing.

void vtkQuaternionInterpolator::InterpolateQuaternion ( double  t,
vtkQuaterniond q 
)

Interpolate the list of quaternions and determine a new quaternion (i.e., fill in the quaternion provided). If t is outside the range of (min,max) values, then t is clamped to lie within the range.

void vtkQuaternionInterpolator::InterpolateQuaternion ( double  t,
double  q[4] 
)

Interpolate the list of quaternions and determine a new quaternion (i.e., fill in the quaternion provided). If t is outside the range of (min,max) values, then t is clamped to lie within the range.

virtual void vtkQuaternionInterpolator::SetInterpolationType ( int  )
virtual

Specify which type of function to use for interpolation. By default (SetInterpolationFunctionToSpline()), cubic spline interpolation using a modifed Kochanek basis is employed. Otherwise, if SetInterpolationFunctionToLinear() is invoked, linear spherical interpolation is used between each pair of quaternions.

virtual int vtkQuaternionInterpolator::GetInterpolationType ( )
virtual

Specify which type of function to use for interpolation. By default (SetInterpolationFunctionToSpline()), cubic spline interpolation using a modifed Kochanek basis is employed. Otherwise, if SetInterpolationFunctionToLinear() is invoked, linear spherical interpolation is used between each pair of quaternions.

void vtkQuaternionInterpolator::SetInterpolationTypeToLinear ( )
inline

Specify which type of function to use for interpolation. By default (SetInterpolationFunctionToSpline()), cubic spline interpolation using a modifed Kochanek basis is employed. Otherwise, if SetInterpolationFunctionToLinear() is invoked, linear spherical interpolation is used between each pair of quaternions.

Definition at line 128 of file vtkQuaternionInterpolator.h.

void vtkQuaternionInterpolator::SetInterpolationTypeToSpline ( )
inline

Specify which type of function to use for interpolation. By default (SetInterpolationFunctionToSpline()), cubic spline interpolation using a modifed Kochanek basis is employed. Otherwise, if SetInterpolationFunctionToLinear() is invoked, linear spherical interpolation is used between each pair of quaternions.

Definition at line 130 of file vtkQuaternionInterpolator.h.

Member Data Documentation

int vtkQuaternionInterpolator::InterpolationType
protected

Definition at line 139 of file vtkQuaternionInterpolator.h.

vtkQuaternionList* vtkQuaternionInterpolator::QuaternionList
protected

Definition at line 142 of file vtkQuaternionInterpolator.h.


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