Ogre::AnimationTrack Class Reference

A 'track' in an animation sequence, ie a sequence of keyframes which affect a certain type of animable object. More...

#include <OgreAnimationTrack.h>

List of all members.

Public Member Functions

AnimationTrack (Animation *parent)

Constructor.

AnimationTrack (Animation *parent, Node *targetNode)

Constructor, associates with a Node.

virtual ~AnimationTrack ()

unsigned short getNumKeyFrames (void) const

Returns the number of keyframes in this animation.

KeyFrame * getKeyFrame (unsigned short index) const

Returns the KeyFrame at the specified index.

Real getKeyFramesAtTime (Real timePos, KeyFrame **keyFrame1, KeyFrame **keyFrame2, unsigned short *firstKeyIndex=0) const

Gets the 2 KeyFrame objects which are active at the time given, and the blend value between them.

KeyFrame * createKeyFrame (Real timePos)

Creates a new KeyFrame and adds it to this animation at the given time index.

void removeKeyFrame (unsigned short index)

Removes a KeyFrame by it's index.

void removeAllKeyFrames (void)

Removes all the KeyFrames from this track.

KeyFrame getInterpolatedKeyFrame (Real timeIndex) const

Gets a KeyFrame object which contains the interpolated transforms at the time index specified.

void apply (Real timePos, Real weight=1.0, bool accumulate=false, Real scale=1.0f)

Applies an animation track at a certain position to the target node.

Node * getAssociatedNode (void) const

Returns a pointer to the associated Node object (if any).

void setAssociatedNode (Node *node)

Sets the associated Node object which will be automatically affected by calls to 'apply'.

void applyToNode (Node *node, Real timePos, Real weight=1.0, bool accumulate=false, Real scale=1.0f)

As the 'apply' method but applies to a specified Node instead of associated node.

void setUseShortestRotationPath (bool useShortestPath)

Sets the method of rotation calculation.

bool getUseShortestRotationPath () const

Gets the method of rotation calculation.

void _keyFrameDataChanged (void) const

Internal method used to tell the track that keyframe data has been changed, which may cause it to rebuild some internal data.

bool hasNonZeroKeyFrames (void) const

Method to determine if this track has any KeyFrames which are doing anything useful - can be used to determine if this track can be optimised out.

void optimise (void)

Optimise the current track by removing any duplicate keyframes.

Protected Types

typedef std::vector< KeyFrame * > KeyFrameList

Protected Member Functions

void buildInterpolationSplines (void) const

Protected Attributes

KeyFrameList mKeyFrames

Real mMaxKeyFrameTime

Animation * mParent

Node * mTargetNode

bool mSplineBuildNeeded

SimpleSpline mPositionSpline

SimpleSpline mScaleSpline

RotationalSpline mRotationSpline

bool mUseShortestRotationPath

Defines if rotation is done using shortest path.

Detailed Description

A 'track' in an animation sequence, ie a sequence of keyframes which affect a certain type of animable object.

Remarks:

This class is intended as a base for more complete classes which will actually animate specific types of object, e.g. a bone in a skeleton to affect skeletal animation. An animation will likely include multiple tracks each of which can be made up of many KeyFrame instances. Note that the use of tracks allows each animable object to have it's own number of keyframes, i.e. you do not have to have the maximum number of keyframes for all animable objects just to cope with the most animated one.

Since the most common animable object is a Node, there are options in this class for associating the track with a Node which will receive keyframe updates automatically when the 'apply' method is called.

By default rotation is done using shortest-path algorithm. It is possible to change this behaviour using setUseShortestRotationPath() method.

Definition at line 54 of file OgreAnimationTrack.h.

Member Typedef Documentation

typedef std::vector<KeyFrame*> Ogre::AnimationTrack::KeyFrameList [protected]

Definition at line 165 of file OgreAnimationTrack.h.

Constructor & Destructor Documentation

Ogre::AnimationTrack::AnimationTrack ( Animation * parent )

Constructor.

Ogre::AnimationTrack::AnimationTrack ( Animation * parent,

Node * targetNode

)

Constructor, associates with a Node.

virtual Ogre::AnimationTrack::~AnimationTrack ( ) [virtual]

Member Function Documentation

void Ogre::AnimationTrack::_keyFrameDataChanged ( void ) const

Internal method used to tell the track that keyframe data has been changed, which may cause it to rebuild some internal data.

void Ogre::AnimationTrack::apply ( Real timePos,

Real weight = 1.0,

bool accumulate = false,

Real scale = 1.0f

)

Applies an animation track at a certain position to the target node.

Remarks:
When a track has bee associated with a target node, you can eaisly apply the animation to the target by calling this method.

Parameters:

timePos The time position in the animation to apply.

weight The influence to give to this track, 1.0 for full influence, less to blend with other animations.

scale The scale to apply to translations and scalings, useful for adapting an animation to a different size target.

void Ogre::AnimationTrack::applyToNode ( Node * node,

Real timePos,

Real weight = 1.0,

bool accumulate = false,

Real scale = 1.0f

)

As the 'apply' method but applies to a specified Node instead of associated node.

void Ogre::AnimationTrack::buildInterpolationSplines ( void ) const [protected]

KeyFrame* Ogre::AnimationTrack::createKeyFrame ( Real timePos )

Creates a new KeyFrame and adds it to this animation at the given time index.

Remarks:
It is better to create KeyFrames in time order. Creating them out of order can result in expensive reordering processing. Note that a KeyFrame at time index 0.0 is always created for you, so you don't need to create this one, just access it using getKeyFrame(0);

Parameters:

timePos The time from which this KeyFrame will apply.

Node* Ogre::AnimationTrack::getAssociatedNode ( void ) const

Returns a pointer to the associated Node object (if any).

KeyFrame Ogre::AnimationTrack::getInterpolatedKeyFrame ( Real timeIndex ) const

Gets a KeyFrame object which contains the interpolated transforms at the time index specified.

Remarks:
The KeyFrame objects held by this class are transformation snapshots at discrete points in time. Normally however, you want to interpolate between these keyframes to produce smooth movement, and this method allows you to do this easily. In animation terminology this is called 'tweening'.

Parameters:

timeIndex The time (in relation to the whole animation sequence)

Returns:
A new keyframe object containing the interpolated transforms. Note that the position and scaling transforms are linearly interpolated (lerp), whilst the rotation is spherically linearly interpolated (slerp) for the most natural result.

KeyFrame* Ogre::AnimationTrack::getKeyFrame ( unsigned short index ) const

Returns the KeyFrame at the specified index.

Real Ogre::AnimationTrack::getKeyFramesAtTime ( Real timePos,

KeyFrame ** keyFrame1,

KeyFrame ** keyFrame2,

unsigned short * firstKeyIndex = 0

) const

Gets the 2 KeyFrame objects which are active at the time given, and the blend value between them.

Remarks:
At any point in time in an animation, there are either 1 or 2 keyframes which are 'active', 1 if the time index is exactly on a keyframe, 2 at all other times i.e. the keyframe before and the keyframe after.

This method returns those keyframes given a time index, and also returns a parametric value indicating the value of 't' representing where the time index falls between them. E.g. if it returns 0, the time index is exactly on keyFrame1, if it returns 0.5 it is half way between keyFrame1 and keyFrame2 etc.

Parameters:

timePos The time index in seconds.

keyFrame1 Pointer to a KeyFrame pointer which will receive the pointer to the keyframe just before or at this time index.

keyFrame2 Pointer to a KeyFrame pointer which will receive the pointer to the keyframe just after this time index.

firstKeyIndex Pointer to an unsigned short which, if supplied, will receive the index of the 'from' keyframe incase the caller needs it.

Returns:
Parametric value indicating how far along the gap between the 2 keyframes the timePos value is, e.g. 0.0 for exactly at 1, 0.25 for a quarter etc. By definition the range of this value is: 0.0 <= returnValue < 1.0 .

unsigned short Ogre::AnimationTrack::getNumKeyFrames ( void ) const

Returns the number of keyframes in this animation.

bool Ogre::AnimationTrack::getUseShortestRotationPath ( ) const

Gets the method of rotation calculation.

bool Ogre::AnimationTrack::hasNonZeroKeyFrames ( void ) const

Method to determine if this track has any KeyFrames which are doing anything useful - can be used to determine if this track can be optimised out.

void Ogre::AnimationTrack::optimise ( void )

Optimise the current track by removing any duplicate keyframes.

void Ogre::AnimationTrack::removeAllKeyFrames ( void )

Removes all the KeyFrames from this track.

void Ogre::AnimationTrack::removeKeyFrame ( unsigned short index )

Removes a KeyFrame by it's index.

void Ogre::AnimationTrack::setAssociatedNode ( Node * node )

Sets the associated Node object which will be automatically affected by calls to 'apply'.

void Ogre::AnimationTrack::setUseShortestRotationPath ( bool useShortestPath )

Sets the method of rotation calculation.

Member Data Documentation

KeyFrameList Ogre::AnimationTrack::mKeyFrames [protected]

Definition at line 166 of file OgreAnimationTrack.h.

Real Ogre::AnimationTrack::mMaxKeyFrameTime [protected]

Definition at line 167 of file OgreAnimationTrack.h.

Animation* Ogre::AnimationTrack::mParent [protected]

Definition at line 168 of file OgreAnimationTrack.h.

SimpleSpline Ogre::AnimationTrack::mPositionSpline [mutable, protected]

Definition at line 176 of file OgreAnimationTrack.h.

RotationalSpline Ogre::AnimationTrack::mRotationSpline [mutable, protected]

Definition at line 178 of file OgreAnimationTrack.h.

SimpleSpline Ogre::AnimationTrack::mScaleSpline [mutable, protected]

Definition at line 177 of file OgreAnimationTrack.h.

bool Ogre::AnimationTrack::mSplineBuildNeeded [mutable, protected]

Definition at line 175 of file OgreAnimationTrack.h.

Node* Ogre::AnimationTrack::mTargetNode [protected]

Definition at line 169 of file OgreAnimationTrack.h.

bool Ogre::AnimationTrack::mUseShortestRotationPath [mutable, protected]

Defines if rotation is done using shortest path.

Definition at line 180 of file OgreAnimationTrack.h.

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

OgreAnimationTrack.h


Public Member Functions
	AnimationTrack (Animation *parent)
	Constructor.
	AnimationTrack (Animation parent, Node targetNode)
	Constructor, associates with a Node.
virtual	~AnimationTrack ()
unsigned short	getNumKeyFrames (void) const
	Returns the number of keyframes in this animation.
KeyFrame *	getKeyFrame (unsigned short index) const
	Returns the KeyFrame at the specified index.
Real	getKeyFramesAtTime (Real timePos, KeyFrame keyFrame1, KeyFrame keyFrame2, unsigned short *firstKeyIndex=0) const
	Gets the 2 KeyFrame objects which are active at the time given, and the blend value between them.
KeyFrame *	createKeyFrame (Real timePos)
	Creates a new KeyFrame and adds it to this animation at the given time index.
void	removeKeyFrame (unsigned short index)
	Removes a KeyFrame by it's index.
void	removeAllKeyFrames (void)
	Removes all the KeyFrames from this track.
KeyFrame	getInterpolatedKeyFrame (Real timeIndex) const
	Gets a KeyFrame object which contains the interpolated transforms at the time index specified.
void	apply (Real timePos, Real weight=1.0, bool accumulate=false, Real scale=1.0f)
	Applies an animation track at a certain position to the target node.
Node *	getAssociatedNode (void) const
	Returns a pointer to the associated Node object (if any).
void	setAssociatedNode (Node *node)
	Sets the associated Node object which will be automatically affected by calls to 'apply'.
void	applyToNode (Node *node, Real timePos, Real weight=1.0, bool accumulate=false, Real scale=1.0f)
	As the 'apply' method but applies to a specified Node instead of associated node.
void	setUseShortestRotationPath (bool useShortestPath)
	Sets the method of rotation calculation.
bool	getUseShortestRotationPath () const
	Gets the method of rotation calculation.
void	_keyFrameDataChanged (void) const
	Internal method used to tell the track that keyframe data has been changed, which may cause it to rebuild some internal data.
bool	hasNonZeroKeyFrames (void) const
	Method to determine if this track has any KeyFrames which are doing anything useful - can be used to determine if this track can be optimised out.
void	optimise (void)
	Optimise the current track by removing any duplicate keyframes.
Protected Types
typedef std::vector< KeyFrame * >	KeyFrameList
Protected Member Functions
void	buildInterpolationSplines (void) const
Protected Attributes
KeyFrameList	mKeyFrames
Real	mMaxKeyFrameTime
Animation *	mParent
Node *	mTargetNode
bool	mSplineBuildNeeded
SimpleSpline	mPositionSpline
SimpleSpline	mScaleSpline
RotationalSpline	mRotationSpline
bool	mUseShortestRotationPath
	Defines if rotation is done using shortest path.