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dtCrowd

Provides local steering behaviors for a group of agents.

API > API/Runtime > API/Runtime/Navmesh

Provides local steering behaviors for a group of agents.

This is the core class of the Crowd module. See the Crowd documentation for a summary of the crowd features.

A common method for setting up the crowd is as follows:

Allocate the crowd using dtAllocCrowd.

Initialize the crowd using init().

Set the avoidance configurations using setObstacleAvoidanceParams().

Add agents using addAgent() and make an initial movement request using requestMoveTarget().

A common process for managing the crowd is as follows:

Call update() to allow the crowd to manage its agents.

Retrieve agent information using getActiveAgents().

Make movement requests using requestMoveTarget() when movement goal changes.

Repeat every frame.

Some agent configuration settings can be updated using updateAgentParameters(). But the crowd owns the agent position. So it is not possible to update an active agent's position. If agent position must be fed back into the crowd, the agent must be removed and re-added.

Notes:

  • Path related information is available for newly added agents only after an update() has been performed.
  • Agent objects are kept in a pool and re-used. So it is important when using agent objects to check the value of dtCrowdAgent::active to determine if the agent is actually in use or not.
  • This class is meant to provide 'local' movement. There is a limit of 256 polygons in the path corridor. So it is not meant to provide automatic pathfinding services over long distances.
   
Name dtCrowd
Type class
Header File /Engine/Source/Runtime/Navmesh/Public/DetourCrowd/DetourCrowd.h
Include Path #include "DetourCrowd/DetourCrowd.h"

Syntax

class dtCrowd

Constructors

Name Remarks Include Path Unreal Specifiers

dtCrowd()

   DetourCrowd/DetourCrowd.h  

Destructors

Name Remarks Include Path Unreal Specifiers

~dtCrowd()

   DetourCrowd/DetourCrowd.h  

Variables

Protected

Name Type Remarks Include Path Unreal Specifiers
m_activeAgents dtCrowdAgent **   DetourCrowd/DetourCrowd.h  
m_agentAnims dtCrowdAgentAnimation *   DetourCrowd/DetourCrowd.h  
m_agents dtCrowdAgent *   DetourCrowd/DetourCrowd.h  
m_agentStateCheckInterval dtReal [UE] time between attempts to restore agents state DetourCrowd/DetourCrowd.h  
m_earlyReachTest bool [UE] if set, crowd agents will use early reach test DetourCrowd/DetourCrowd.h  
m_ext dtReal   DetourCrowd/DetourCrowd.h  
m_filters dtQueryFilter   DetourCrowd/DetourCrowd.h  
m_grid dtProximityGrid *   DetourCrowd/DetourCrowd.h  
m_keepOffmeshConnections bool [UE] if set, offmesh connections won't be cut from corridor DetourCrowd/DetourCrowd.h  
m_maxAgentRadius dtReal   DetourCrowd/DetourCrowd.h  
m_maxAgents int   DetourCrowd/DetourCrowd.h  
m_maxPathResult int   DetourCrowd/DetourCrowd.h  
m_navquery dtNavMeshQuery *   DetourCrowd/DetourCrowd.h  
m_numActiveAgents int   DetourCrowd/DetourCrowd.h  
m_obstacleQuery dtObstacleAvoidanceQuery *   DetourCrowd/DetourCrowd.h  
m_obstacleQueryParams dtObstacleAvoidanceParams   DetourCrowd/DetourCrowd.h  
m_pathOffsetRadiusMultiplier dtReal [UE] radius multiplier for offseting path around corners DetourCrowd/DetourCrowd.h  
m_pathq dtPathQueue   DetourCrowd/DetourCrowd.h  
m_pathResult dtPolyRef *   DetourCrowd/DetourCrowd.h  
m_raycastFilter dtQueryFilter   DetourCrowd/DetourCrowd.h  
m_raycastSingleArea bool [UE] if set, path visibility optimization can't leave current area type DetourCrowd/DetourCrowd.h  
m_separationDirFilter dtReal [UE] separation filter DetourCrowd/DetourCrowd.h  
m_sharedBoundary dtSharedBoundary   DetourCrowd/DetourCrowd.h  
m_velocitySampleCount int   DetourCrowd/DetourCrowd.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

int addAgent ( const dtReal* pos,
const dtCrowdAgentParams& params,
const dtQueryFilter* filter
)

 Adds a new agent to the crowd. DetourCrowd/DetourCrowd.h  

int cacheActiveAgents()

 Cache list of active agents DetourCrowd/DetourCrowd.h  
Gets all cached active agents. DetourCrowd/DetourCrowd.h  

int getActiveAgents ( dtCrowdAgent** agents,
const int maxAgents
)

 Gets the active agents int the agent pool. DetourCrowd/DetourCrowd.h  

const dtCrowdAgent * getAgent ( const int idx
)

 Gets the specified agent from the pool. DetourCrowd/DetourCrowd.h  

const dtCrowdAgentAnimation * getAgentAnims()

 Gets all agent animations. DetourCrowd/DetourCrowd.h  

const int getAgentCount()

 The maximum number of agents that can be managed by the object. DetourCrowd/DetourCrowd.h  

int getAgentIndex ( const dtCrowdAgent* agent
) const

   DetourCrowd/DetourCrowd.h  

dtQueryFilter * getEditableFilter ( const int idx
)

 Gets the filter used by the crowd. DetourCrowd/DetourCrowd.h  

const dtQueryFilter * getFilter ( const int idx
) const

 Gets the filter used by the crowd. DetourCrowd/DetourCrowd.h  

const dtProximityGrid * getGrid()

 Gets the crowd's proximity grid. DetourCrowd/DetourCrowd.h  

const dtNavMeshQuery * getNavMeshQuery()

 Gets the query object used by the crowd. DetourCrowd/DetourCrowd.h  

int getNumActiveAgents()

   DetourCrowd/DetourCrowd.h  

const dtObstacleAvoidanceParams * getObstacleAvoidanceParams ( const int idx
) const

 Gets the shared avoidance configuration for the specified index. DetourCrowd/DetourCrowd.h  

bool getObstacleAvoidancePattern ( int idx,
dtReal* angles,
dtReal* radii,
int* nsamples
)

 [UE] Gets the shared avoidance sampling pattern for the specified index. DetourCrowd/DetourCrowd.h  

const dtPathQueue * getPathQueue()

 Gets the crowd's path request queue. DetourCrowd/DetourCrowd.h  

const dtReal * getQueryExtents()

 Gets the search extents [(x, y, z)] used by the crowd for query operations. DetourCrowd/DetourCrowd.h  

const dtSharedBoundary * getSharedBoundary()

 Gets shared boundary cache. DetourCrowd/DetourCrowd.h  

int getVelocitySampleCount()

 Gets the velocity sample count. DetourCrowd/DetourCrowd.h  

bool init ( const int maxAgents,
const dtReal maxAgentRadius,
dtNavMesh* nav
)

 Initializes the crowd. May be called more than once to purge and re-initialize the crowd. DetourCrowd/DetourCrowd.h  

bool initAvoidance ( const int maxNeighbors,
const int maxWalls,
const int maxCustomPatterns
)

 [UE] Initializes the avoidance query. DetourCrowd/DetourCrowd.h  

bool isOutsideCorridor ( const int idx
) const

 [UE] Check if agent moved away from its path corridor DetourCrowd/DetourCrowd.h  

void removeAgent ( const int idx
)

 Removes the agent from the crowd. DetourCrowd/DetourCrowd.h  

bool requestMoveTarget ( const int idx,
dtPolyRef ref,
const dtReal* pos
)

 Submits a new move request for the specified agent. DetourCrowd/DetourCrowd.h  

bool requestMoveVelocity ( const int idx,
const dtReal* vel
)

 Submits a new move request for the specified agent. DetourCrowd/DetourCrowd.h  

bool resetAgentVelocity ( const int idx
)

 [UE] Resets agent's velocity DetourCrowd/DetourCrowd.h  

bool resetMoveTarget ( const int idx
)

 Resets any request for the specified agent. DetourCrowd/DetourCrowd.h  

bool setAgentBackOnLink ( const int idx
)

 [UE] Switch to offmesh link state DetourCrowd/DetourCrowd.h  

void setAgentCheckInterval ( const dtReal t
)

 [UE] Set time between attempts to restore agents state DetourCrowd/DetourCrowd.h  

bool setAgentCorridor ( const int idx,
const dtPolyRef* path,
const int npath
)

 [UE] Set agent corridor, works only just after requesting move target when agent didn't start any pathfinding operations yet Use with caution! DetourCrowd/DetourCrowd.h  

bool setAgentWaiting ( const int idx
)

 [UE] Switch to waiting state DetourCrowd/DetourCrowd.h  

void setEarlyReachTestOptimization ( bool bEnable
)

 [UE] DetourCrowd/DetourCrowd.h  

void setObstacleAvoidanceParams ( const int idx,
const dtObstacleAvoidanceParams* params
)

 Sets the shared avoidance configuration for the specified index. DetourCrowd/DetourCrowd.h  

void setObstacleAvoidancePattern ( int idx,
const dtReal* angles,
const dtReal* radii,
int nsamples
)

 [UE] Sets the shared avoidance sampling pattern for the specified index. DetourCrowd/DetourCrowd.h  

void setPathOffsetRadiusMultiplier ( dtReal RadiusMultiplier
)

 [UE] Set agent radius multiplier for offseting path from corners DetourCrowd/DetourCrowd.h  

void setPruneStartedOffmeshConnections ( bool bRemoveFromCorridor
)

 [UE] Set offmesh connection pruning This will allow removing offmesh connection poly ref from corridor as soon as offmesh connection anim is triggered (default behavior) DetourCrowd/DetourCrowd.h  

void setSeparationFilter ( dtReal InFilter
)

 [UE] Set separation filter param DetourCrowd/DetourCrowd.h  

void setSingleAreaVisibilityOptimization ( bool bEnable
)

 [UE] Set visibility optimization to use single area raycasts This will prevent from cutting through polys marked as different area which could have been avoided in corridor's path DetourCrowd/DetourCrowd.h  

void update ( const dtReal dt,
dtCrowdAgentDebugInfo* debug
)

 Updates the steering and positions of all agents. DetourCrowd/DetourCrowd.h  

bool updateAgentFilter ( const int idx,
const dtQueryFilter* filter
)

 [UE] Updates the specified agent's query filter. DetourCrowd/DetourCrowd.h  

void updateAgentParameters ( const int idx,
const dtCrowdAgentParams& params
)

 Updates the specified agent's configuration. DetourCrowd/DetourCrowd.h  

void updateAgentState ( const int idx,
bool repath
)

 [UE] Refresh state of agent, used after completing movement through offmesh links DetourCrowd/DetourCrowd.h  

void updateStepAvoidance ( const dtReal dt,
dtCrowdAgentDebugInfo* debug
)

 [UE] Split update into several smaller components: avoidance DetourCrowd/DetourCrowd.h  

void updateStepCorridor ( const dtReal dt,
dtCrowdAgentDebugInfo* debug
)

 [UE] Split update into several smaller components: corridor updates at new position DetourCrowd/DetourCrowd.h  

void updateStepMove ( const dtReal dt,
dtCrowdAgentDebugInfo* debug
)

 [UE] Split update into several smaller components: integrate velocities and handle collisions DetourCrowd/DetourCrowd.h  

void updateStepNextMovePoint ( const dtReal dt,
dtCrowdAgentDebugInfo* debug
)

 [UE] Split update into several smaller components: next corner for move, trigger offmesh links DetourCrowd/DetourCrowd.h  

void updateStepOffMeshAnim ( const dtReal dt,
dtCrowdAgentDebugInfo* debug
)

 [UE] Split update into several smaller components: offmesh anims DetourCrowd/DetourCrowd.h  

void updateStepOffMeshVelocity ( const dtReal dt,
dtCrowdAgentDebugInfo* debug
)

 [UE] Split update into several smaller components: offmesh link velocity (instead of playing animation) DetourCrowd/DetourCrowd.h  

void updateStepPaths ( const dtReal dt,
dtCrowdAgentDebugInfo* debug
)

 [UE] Split update into several smaller components: path validity, path cache and path optimizations DetourCrowd/DetourCrowd.h  

void updateStepProximityData ( const dtReal dt,
dtCrowdAgentDebugInfo* debug
)

 [UE] Split update into several smaller components: neighbors and boundaries DetourCrowd/DetourCrowd.h  

void updateStepSteering ( const dtReal dt,
dtCrowdAgentDebugInfo* debug
)

 [UE] Split update into several smaller components: steering DetourCrowd/DetourCrowd.h  

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