ezEngine  Release 25.03
ezFollowPathComponent Class Reference

This component makes the ezGameObject, that it is attached to, move along a path defined by an ezPathComponent. More...

#include <FollowPathComponent.h>

Inheritance diagram for ezFollowPathComponent:

Public Member Functions

virtual void SerializeComponent (ezWorldWriter &ref_stream) const override
 Override this to save the current state of the component to the given stream.
 
virtual void DeserializeComponent (ezWorldReader &ref_stream) override
 Override this to load the current state of the component from the given stream. More...
 
void SetPathObject (const char *szReference)
 Sets the reference to the game object on which an ezPathComponent should be attached.
 
void SetDistanceAlongPath (float fDistance)
 Distance along the path at which the ezFollowPathComponent should start off.
 
float GetDistanceAlongPath () const
 
void SetDirectionForwards (bool bForwards)
 Whether the component should move along the path 'forwards' or 'backwards'.
 
void ToggleDirection ()
 Toggles the direction that it travels along the path.
 
bool IsDirectionForwards () const
 Whether the component currently moves 'forwards' along the path. More...
 
bool IsRunning () const
 Whether the component currently moves along the path, at all.
 
void SetRunning (bool bRunning)
 Whether to move along the path or not.
 
- Public Member Functions inherited from ezComponent
void SetActiveFlag (bool bEnabled)
 Sets the active flag of the component, which affects its active state. More...
 
bool GetActiveFlag () const
 Checks whether the 'active flag' is set on this component. Note that this does not mean that the component is also 'active'. More...
 
bool IsActive () const
 Checks whether this component is in an active state. More...
 
bool IsActiveAndInitialized () const
 Returns whether this component is active and initialized. More...
 
bool IsActiveAndSimulating () const
 Whether the component is currently active and simulation has been started as well. More...
 
ezComponentManagerBaseGetOwningManager ()
 Returns the corresponding manager for this component.
 
const ezComponentManagerBaseGetOwningManager () const
 Returns the corresponding manager for this component.
 
ezGameObjectGetOwner ()
 Returns the owner game object if the component is attached to one or nullptr.
 
const ezGameObjectGetOwner () const
 Returns the owner game object if the component is attached to one or nullptr.
 
ezWorldGetWorld ()
 Returns the corresponding world for this component.
 
const ezWorldGetWorld () const
 Returns the corresponding world for this component.
 
ezComponentHandle GetHandle () const
 Returns a handle to this component.
 
ezUInt32 GetUniqueID () const
 Returns the unique id for this component.
 
void SetUniqueID (ezUInt32 uiUniqueID)
 Sets the unique id for this component.
 
void EnsureInitialized ()
 Ensures that the component is initialized. Must only be called from another component's Initialize callback.
 
void EnsureSimulationStarted ()
 Ensures that the OnSimulationStarted method has been called. Must only be called from another component's OnSimulationStarted callback.
 
EZ_ALWAYS_INLINE bool SendMessage (ezMessage &ref_msg)
 Sends a message to this component.
 
EZ_ALWAYS_INLINE bool SendMessage (ezMessage &ref_msg) const
 
void PostMessage (const ezMessage &msg, ezTime delay=ezTime::MakeZero(), ezObjectMsgQueueType::Enum queueType=ezObjectMsgQueueType::NextFrame) const
 Queues the message for the given phase. The message is processed after the given delay in the corresponding phase.
 
virtual bool HandlesMessage (const ezMessage &msg) const
 Returns whether the given Message is handled by this component.
 
void SetUserFlag (ezUInt8 uiFlagIndex, bool bSet)
 Be careful to check which flags may already be in use by base classes.
 
bool GetUserFlag (ezUInt8 uiFlagIndex) const
 Retrieves a custom flag. Index must be between 0 and 7.
 
void SetCreatedByPrefab ()
 Adds ezObjectFlags::CreatedByPrefab to the component. See the flag for details.
 
bool WasCreatedByPrefab () const
 Checks whether the ezObjectFlags::CreatedByPrefab flag is set on this component.
 
- Public Member Functions inherited from ezReflectedClass
virtual const ezRTTIGetDynamicRTTI () const
 
bool IsInstanceOf (const ezRTTI *pType) const
 Returns whether the type of this instance is of the given type or derived from it.
 
template<typename T >
EZ_ALWAYS_INLINE bool IsInstanceOf () const
 Returns whether the type of this instance is of the given type or derived from it.
 

Public Attributes

ezEnum< ezPropertyAnimModem_Mode
 [ property ] How the path should be traversed.
 
ezEnum< ezFollowPathModem_FollowMode
 [ property ] How the transform of the follower should be affected by the path.
 
float m_fSpeed = 1.0f
 [ property ] How fast to move along the path.
 
float m_fLookAhead = 1.0f
 [ property ] How far along the path to 'look ahead' to smooth the rotation. A small distance means rotations are very abrupt.
 
float m_fSmoothing = 0.5f
 [ property ] How much to combine the current position with the new position. 0 to 1. At zero, the position follows the path perfectly, but therefore also has very abrupt changes. With a lot of smoothing, the path becomes very sluggish.
 
float m_fTiltAmount = 5.0f
 [ property ] How much to tilt when turning.
 
ezAngle m_MaxTilt = ezAngle::MakeFromDegree(30.0f)
 [ property ] The max tilt angle of the object.
 

Protected Member Functions

virtual void OnActivated () override
 This method is called when the component gets activated. More...
 
virtual void OnSimulationStarted () override
 This method is called once for active components, at the start of the next world update, but only when the world is simulated. More...
 
void Update (bool bForce=false)
 
const char * DummyGetter () const
 
- Protected Member Functions inherited from ezComponent
 ezComponent ()
 Keep the constructor private or protected in derived classes, so it cannot be called manually.
 
bool IsDynamic () const
 Returns whether this component is dynamic and thus can only be attached to dynamic game objects.
 
virtual ezWorldModuleTypeId GetTypeId () const =0
 
virtual ezComponentMode::Enum GetMode () const =0
 
virtual void Initialize ()
 Can be overridden for basic initialization that depends on a valid hierarchy and position. More...
 
virtual void Deinitialize ()
 This method is called before the component is destroyed. A derived type can override this method to do common de-initialization work. More...
 
virtual void OnDeactivated ()
 This method is called when the component gets deactivated. More...
 
void EnableUnhandledMessageHandler (bool enable)
 By default disabled. Enable to have OnUnhandledMessage() called for every unhandled message.
 
virtual bool OnUnhandledMessage (ezMessage &msg, bool bWasPostedMsg)
 When EnableUnhandledMessageHandler() was activated, this is called for all messages for which there is no dedicated message handler. More...
 
virtual bool OnUnhandledMessage (ezMessage &msg, bool bWasPostedMsg) const
 When EnableUnhandledMessageHandler() was activated, this is called for all messages for which there is no dedicated message handler. More...
 
bool IsInitialized () const
 
bool IsInitializing () const
 
bool IsSimulationStarted () const
 

Protected Attributes

ezEventMessageSender< ezMsgAnimationReachedEndm_ReachedEndEvent
 
ezGameObjectHandle m_hPathObject
 
ezPathComponent::LinearSampler m_PathSampler
 
float m_fStartDistance = 0.0f
 
bool m_bLastStateValid = false
 
bool m_bIsRunning = true
 
bool m_bIsRunningForwards = true
 
ezVec3 m_vLastPosition
 
ezVec3 m_vLastTargetPosition
 
ezVec3 m_vLastUpDir
 
ezAngle m_LastTiltAngle
 
- Protected Attributes inherited from ezComponent
const ezRTTIm_pMessageDispatchType = nullptr
 Messages will be dispatched to this type. Default is what GetDynamicRTTI() returns, can be redirected if necessary.
 

Additional Inherited Members

- Static Public Member Functions inherited from ezNoBase
static const ezRTTIGetStaticRTTI ()
 

Detailed Description

This component makes the ezGameObject, that it is attached to, move along a path defined by an ezPathComponent.

Build a path using an ezPathComponent and ezPathNodeComponents. Then attach an ezFollowPathComponent to a free-standing ezGameObject and reference the object with the ezPathComponent in it.

During simulation the ezFollowPathComponent will now move and rotate its owner object such that it moves along the path.

The start location of the 'hook' (the object with the ezFollowPathComponent on it) may be anywhere. It will be teleported onto the path. For many objects this is not a problem, but physically simulated objects may be very sensitive about this.

One option is to align the 'hook' perfectly with the start location. You can achieve this, using the "Keep Simulation Changes" feature of the editor (simulate with zero speed, press K, stop simulation). Another option is to instead delay the spawning of the object below the hook, by using an ezSpawnComponent next to the ezFollowPathComponent, and thus have the payload spawn only after the hook has been placed properly.

Member Function Documentation

◆ DeserializeComponent()

void ezFollowPathComponent::DeserializeComponent ( ezWorldReader inout_stream)
overridevirtual

Override this to load the current state of the component from the given stream.

The active state will be automatically serialized. The 'initialized' state is not serialized, all components will be initialized after creation, even if they were already in an initialized state when they were serialized.

Reimplemented from ezComponent.

◆ IsDirectionForwards()

bool ezFollowPathComponent::IsDirectionForwards ( ) const

Whether the component currently moves 'forwards' along the path.

Note that if the 'speed' property is negative, moving 'forwards' along the path still means that it effectively moves backwards.

◆ OnActivated()

void ezFollowPathComponent::OnActivated ( )
overrideprotectedvirtual

This method is called when the component gets activated.

By default a component is active, but it can be created in an inactive state. In such a case OnActivated() is only called once a component is activated. If a component gets switched between active and inactive at runtime, OnActivated() and OnDeactivated() are called accordingly. In contrast Initialize() and Deinitialize() are only ever called once.

See also
OnActivated(), OnDeactivated(), Initialize(), Deinitialize(), OnSimulationStarted()

Reimplemented from ezComponent.

◆ OnSimulationStarted()

void ezFollowPathComponent::OnSimulationStarted ( )
overrideprotectedvirtual

This method is called once for active components, at the start of the next world update, but only when the world is simulated.

This is the one preferred method to setup typical game logic. In a pure game environment there is no practical difference between OnActivated() and OnSimulationStarted(), as OnSimulationStarted() will be called right after OnActivated().

However, when a scene is open inside the editor, there is an important difference: OnActivated() is called once the component was created. OnSimulationStarted() is only called once the game simulation is started inside the editor. As an example, if a component starts a sound in OnActivated(), that sound will play right after the scene has been loaded into the editor. If instead the sound gets started in OnSimulationStarted(), it will only play once the user starts the game mode inside the editor.

Additionally, OnSimulationStarted() is only executed once, even if the ezWorld pauses and resumes world simulation multiple times. However, note that it will be called again after the component has been deactivated and is activated again.

See also
OnActivated(), OnDeactivated(), Initialize(), Deinitialize(), OnSimulationStarted()

Reimplemented from ezComponent.


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