Animates an object or camera along a track More...
#include <Inventor/engines/SoTrackFollower.h>
Public Member Functions | |
virtual SoType | getTypeId () const |
Returns the type identifier for this specific instance. | |
SoTrackFollower () | |
Constructor. | |
Public Member Functions inherited from SoEngine | |
virtual int | getOutputs (SoEngineOutputList &list) const |
Returns a list of outputs in this engine. | |
SoEngineOutput * | getOutput (const SbName &outputName) const |
Returns a reference to the engine output with the given name. | |
SbBool | getOutputName (const SoEngineOutput *output, SbName &outputName) const |
Returns (in outputName) the name of the engine output (output). | |
SoEngine * | copy () const |
Creates and returns an exact copy of the engine. | |
Public Member Functions inherited from SoFieldContainer | |
void | setToDefaults () |
Sets all fields in this object to their default values. | |
SbBool | hasDefaultValues () const |
Returns TRUE if all of the object's fields have their default values. | |
SbBool | fieldsAreEqual (const SoFieldContainer *fc) const |
Returns TRUE if this object's fields are exactly equal to fc's fields. | |
void | copyFieldValues (const SoFieldContainer *fc, SbBool copyConnections=FALSE) |
Copies the contents of fc's fields into this object's fields. | |
SoNONUNICODE SbBool | set (const char *fieldDataString) |
Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format. | |
SbBool | set (const SbString &fieldDataString) |
Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format. | |
void | get (SbString &fieldDataString) |
Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string. | |
virtual int | getFields (SoFieldList &list) const |
Appends references to all of this object's fields to resultList, and returns the number of fields appended. | |
virtual int | getAllFields (SoFieldList &list) const |
Returns a list of fields, including the eventIn's and eventOut's. | |
virtual SoField * | getField (const SbName &fieldName) const |
Returns a the field of this object whose name is fieldName. | |
virtual SoField * | getEventIn (const SbName &fieldName) const |
Returns a the eventIn with the given name. | |
virtual SoField * | getEventOut (const SbName &fieldName) const |
Returns the eventOut with the given name. | |
SbBool | getFieldName (const SoField *field, SbName &fieldName) const |
Returns the name of the given field in the fieldName argument. | |
SbBool | enableNotify (SbBool flag) |
Notification at this Field Container is enabled (if flag == TRUE) or disabled (if flag == FALSE). | |
SbBool | isNotifyEnabled () const |
Notification is the process of telling interested objects that this object has changed. | |
virtual void | setUserData (void *data) |
Sets application data. | |
void * | getUserData (void) const |
Gets user application data. | |
Public Member Functions inherited from SoBase | |
virtual void | touch () |
Marks an instance as modified, simulating a change to it. | |
virtual SbName | getName () const |
Returns the name of an instance. | |
virtual void | setName (const SbName &name) |
Sets the name of an instance. | |
void | setSynchronizable (const bool b) |
Sets this to be a ScaleViz synchronizable object. | |
bool | isSynchronizable () const |
Gets the ScaleViz synchronizable state of this object. | |
Public Member Functions inherited from SoRefCounter | |
void | ref () const |
Adds a reference to an instance. | |
void | unref () const |
Removes a reference from an instance. | |
void | unrefNoDelete () const |
unrefNoDelete() should be called when it is desired to decrement the reference count, but not delete the instance if this brings the reference count to zero. | |
int | getRefCount () const |
Returns current reference count. | |
void | lock () const |
lock this instance. | |
void | unlock () const |
unlock this instance. | |
Public Member Functions inherited from SoTypedObject | |
SbBool | isOfType (const SoType &type) const |
Returns TRUE if this object is of the type specified in type or is derived from that type. | |
template<typename TypedObjectClass > | |
SbBool | isOfType () const |
Returns TRUE if this object is of the type of class TypedObjectClass or is derived from that class. | |
Static Public Member Functions | |
static SoType | getClassTypeId () |
Returns the type identifier for this class. | |
Static Public Member Functions inherited from SoEngine | |
static SoType | getClassTypeId () |
Returns the type identifier for the SoEngine class. | |
static SoEngine * | getByName (const SbName &name) |
Looks up engine(s) by name. | |
static int | getByName (const SbName &name, SoEngineList &list) |
Looks up engine(s) by name. | |
Static Public Member Functions inherited from SoFieldContainer | |
static SoType | getClassTypeId () |
Returns the type of this class. | |
Static Public Member Functions inherited from SoBase | |
static SoType | getClassTypeId () |
Returns type identifier for this class. | |
Static Public Member Functions inherited from SoTypedObject | |
static SoType | getClassTypeId () |
Returns the type identifier for this class. | |
Public Attributes | |
SoMFVec3f | points |
Coordinates of the control points. | |
SoMFFloat | timeStamps |
Time stamps associated with the control points. | |
SoMFFloat | radius |
Radius of the turn at a control point. | |
SoMFFloat | rollAngle |
Roll angle during the turn at a control point. | |
SoMFFloat | rollSpeed |
Speed at which the roll angle is reached during a turn. | |
SoMFBool | keepRollAngle |
Indicates if the roll angle should be maintained after the middle of the turn. | |
SoMFRotation | headRotation |
The final rotation applied at a control point, which allows the camera or the object to be rotated while following the track. | |
SoSFFloat | alpha |
The value on which the interpolation is made. | |
SoSFBool | loop |
If loop is TRUE, the animation will loop. | |
SoSFBool | useHeadRotationOnly |
If TRUE, the orientation output field is a direct interpolation of headRotation values, without taking into consideration the roll angle or the track itself. | |
SoEngineOutput | position |
(SoSFVec3f) Position interpolated from the alpha value. | |
SoEngineOutput | orientation |
(SoSFRotation) Rotation interpolated from the alpha value. | |
Animates an object or camera along a track
This engine is designed to add animations to a scene graph. It manages a track that can be followed either by an object (a sub scene graph) or by a camera. The track is defined by a set of control points. Each control point can be associated with a time stamp, a turn angle, roll information, and a head rotation. Only the points field is required. All other data fields are optional.
The input that drives the animation is the alpha field. This value should vary between 0 and 1, assuming 0 as the position and orientation at the first control point, and 1 as the position and orientation at the last control point. Alpha values are clamped to the interval [0,1]. An SoTimerSensor or other engines can be used to dynamically modify the alpha value.
The outputs are a position field and an orientation field that can be connected directly to the corresponding fields of an SoCamera or SoTransform node (see SoField::connectFrom). The values of these fields are computed by interpolating the track points with the alpha field value.
The rollAngle values are only used if the track specified by the points field is curved.
An example .iv file using SoTrackFollower is provided in the directory $OIVHOME/data/models/toys/TrackSample.
points | 0 0 0 |
timeStamps | 0 |
radius | 0 |
rollAngle | 0 |
rollSpeed | 0 |
keepRollAngle | FALSE |
headRotation | 0 0 1 0 |
alpha | 0 |
loop | TRUE |
useHeadRotationOnly | FALSE |
Definition at line 103 of file SoTrackFollower.h.
SoTrackFollower::SoTrackFollower | ( | ) |
Constructor.
|
static |
Returns the type identifier for this class.
|
virtual |
Returns the type identifier for this specific instance.
Implements SoTypedObject.
SoSFFloat SoTrackFollower::alpha |
The value on which the interpolation is made.
It must between 0.0 and 1.0.
Definition at line 213 of file SoTrackFollower.h.
SoMFRotation SoTrackFollower::headRotation |
The final rotation applied at a control point, which allows the camera or the object to be rotated while following the track.
If there are fewer headRotation values than control points, the value of the last headRotation is used for the remaining control points.
Definition at line 208 of file SoTrackFollower.h.
SoMFBool SoTrackFollower::keepRollAngle |
Indicates if the roll angle should be maintained after the middle of the turn.
If this flag is set to TRUE for a control point, the roll speed is assumed to be 1 in the second part of the turn for the current control point and in the first part of the turn for the next control point. This allows the roll angle to be maintained between two adjacent turns.
If there are fewer keepRollAngle values than control points, the value of the last keepRollAngle is used for the remaining control points.
Definition at line 199 of file SoTrackFollower.h.
SoSFBool SoTrackFollower::loop |
If loop is TRUE, the animation will loop.
For N control points, there must be N+1 time stamps. The last time stamp is used for interpolating between the last control point and the first control point at the end of the animation loop. For example, if there are four points (P1, P2, P3, and P4), there must be five time stamps (T1,... T5) as shown below:
Definition at line 225 of file SoTrackFollower.h.
SoEngineOutput SoTrackFollower::orientation |
(SoSFRotation) Rotation interpolated from the alpha value.
It's a rotation from the -Z vector to the heading vector, with the initial up vector along the Y vector.
Definition at line 246 of file SoTrackFollower.h.
SoMFVec3f SoTrackFollower::points |
Coordinates of the control points.
Definition at line 113 of file SoTrackFollower.h.
SoEngineOutput SoTrackFollower::position |
(SoSFVec3f) Position interpolated from the alpha value.
Definition at line 239 of file SoTrackFollower.h.
SoMFFloat SoTrackFollower::radius |
Radius of the turn at a control point.
If radius is zero for a control point (the default), the orientation changes immediately when the animation reachs that point. For many animations this is an unrealistic or undesirable behavior. Radius values allow the orientation to change smoothly, following a curve.
If there are fewer radius values than control points, the value of the last radius is used for the remaining control points.
Definition at line 156 of file SoTrackFollower.h.
SoMFFloat SoTrackFollower::rollAngle |
Roll angle during the turn at a control point.
The roll angle inclines the track inside the turn. If the specified roll angle is negative, the track is inclined outside the turn.
If rollAngle is zero for a control point (the default), the animated object will rotate around a vector perpendicular to the plane defined by the preceding and following segments of the track. This is typically the desired behavior, for example, when animating a vehicle on the ground. However rollAngle allows a more realistic animation of a flying vehicle.
If there are fewer rollAngle values than control points, the value of the last rollAngle is used for the remaining control points.
Definition at line 174 of file SoTrackFollower.h.
SoMFFloat SoTrackFollower::rollSpeed |
Speed at which the roll angle is reached during a turn.
By default, (value = 0) the roll angle varies from 0 at the beginning of the turn to the specified roll angle value in the middle of the turn and then back to 0 at the end of the turn. A value of 1 means the roll angle is immediately reached at the begining of the turn. Intermediate values vary the point at which the full roll angle is reached.
If there are fewer rollSpeed values than control points, the value of the last rollSpeed is used for the remaining control points.
Definition at line 187 of file SoTrackFollower.h.
SoMFFloat SoTrackFollower::timeStamps |
Time stamps associated with the control points.
A time stamp represents the time at which a control point must be reached; the "scale" of the time is independent of the animation time. However, it is proportional to it. For example, if point 1 has a time stamp value of 10, point 2 has a time stamp value of 30, and point 3 has a time stamp value of 40, it means that the interpolation will take twice as long to go from point 1 to point 2 (20 time units) as it will to go from point 2 to point 3 (10 time units). The actual time to complete an animation, and therefore the overall speed, is determined by the time it takes for the alpha value to go from 0 to 1. In other words, the overall speed is controlled by the application or another engine which is updating the alpha input.
If a time stamp has a value of SO_UNDEFINED_TIME_STAMP (default value), then the computed time stamp is proportional to the distance between the previous and the next control point, i.e., speed is constant. If all the time stamps are set to SO_UNDEFINED_TIME_STAMP or are not set at all, they are all computed to be proportional to the distance between the points, and speed is constant over the entire track.
If the time stamp field contains one more value than the points field, the last time stamp is assumed to apply to the first/last control point in a loop. If fewer than 3 time stamps are provided, the track is interpolated proportional to the distance between control points.
Definition at line 144 of file SoTrackFollower.h.
SoSFBool SoTrackFollower::useHeadRotationOnly |
If TRUE, the orientation output field is a direct interpolation of headRotation values, without taking into consideration the roll angle or the track itself.
Definition at line 232 of file SoTrackFollower.h.