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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 Methods

 AnimationTrack (Animation *parent)
 Constructor. More...

 AnimationTrack (Animation *parent, Node *targetNode)
 Constructor, associates with a Node. More...

virtual ~AnimationTrack ()
unsigned short getNumKeyFrames (void) const
 Returns the number of keyframes in this animation. More...

KeyFrame * getKeyFrame (unsigned short index) const
 Returns the KeyFrame at the specified index. More...

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. More...

KeyFrame * createKeyFrame (Real timePos)
 Creates a new KeyFrame and adds it to this animation at the given time index. More...

void removeKeyFrame (unsigned short index)
 Removes a KeyFrame by it's index. More...

void removeAllKeyFrames (void)
 Removes all the KeyFrames from this track. More...

KeyFrame getInterpolatedKeyFrame (Real timeIndex) const
 Gets a KeyFrame object which contains the interpolated transforms at the time index specified. More...

void apply (Real timePos, Real weight=1.0, bool accumulate=false)
 Applies an animation track at a certain position to the target node. More...

Node * getAssociatedNode (void) const
 Returns a pointer to the associated Node object (if any). More...

void setAssociatedNode (Node *node)
 Sets the associated Node object which will be automatically affected by calls to 'apply'. More...

void applyToNode (Node *node, Real timePos, Real weight=1.0, bool accumulate=false)
 As the 'apply' method but applies to a specified Node instead of associated node. More...


Protected Types

typedef std::vector< KeyFrame * > KeyFrameList

Protected Methods

void buildInterpolationSplines (void) const

Protected Attributes

KeyFrameList mKeyFrames
Real mMaxKeyFrameTime
Animation * mParent
Node * mTargetNode
bool mSplineBuildNeeded
SimpleSpline mPositionSpline
SimpleSpline mScaleSpline
RotationalSpline mRotationSpline

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.

Member Typedef Documentation

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

Constructor & Destructor Documentation

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

Constructor.

Ogre::AnimationTrack::AnimationTrack (  Animation *    parent,
Node *    targetNode
) 
 

Constructor, associates with a Node.

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

Member Function Documentation

void Ogre::AnimationTrack::apply (  Real    timePos,
Real    weight = 1.0,
bool    accumulate = false
) 
 

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.

void Ogre::AnimationTrack::applyToNode (  Node *    node,
Real    timePos,
Real    weight = 1.0,
bool    accumulate = false
) 
 

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.

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'.

Member Data Documentation

KeyFrameList Ogre::AnimationTrack::mKeyFrames [protected]
 

Real Ogre::AnimationTrack::mMaxKeyFrameTime [protected]
 

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

SimpleSpline Ogre::AnimationTrack::mPositionSpline [protected]
 

RotationalSpline Ogre::AnimationTrack::mRotationSpline [protected]
 

SimpleSpline Ogre::AnimationTrack::mScaleSpline [protected]
 

bool Ogre::AnimationTrack::mSplineBuildNeeded [protected]
 

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

Copyright © 2002 by The OGRE Team