DoN's 3D-Pathfinding / Flying-AI system (with full source!)

[Grot13]

@Paul_LTC The skeletal system is the same, but instead of moving the capsule with "add input" (and using character movement component), I've made the capsule simulating physics without gravity (important) and it is moved by a radial force (then just have to play with physic parameters, especially dampings of the capsule). I don't really need any physic volume but it works if I put one in the scene (that's why I think the volume is not an obstacle).

If using a character instead of pawn, the movement component gives more options, but I don't know if one option can allow "add movement input" inside of a volume...

[Angius]

So, the plugin suddenly started making problems. Haven't changed anything about the nav, as I've been dealing with level design recently. And yet – what used to work, now crashes the engine.

 

Spoiler

Access violation - code c0000005 (first/second chance not available)

UE4Editor_DonAINavigation!TSet<AActor *,DefaultKeyFuncs<AActor *,0>,FDefaultSetAllocator>::FindId() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\core\public\containers\set.h:631]
UE4Editor_DonAINavigation!UBTTask_FlyTo::SchedulePathfindingRequest() [g:\engines\unreal\source\ue_4_20\engine\plugins\marketplace\donainavigation\source\donainavigation\private\behaviortree\bttask_flyto.cpp:92]
UE4Editor_DonAINavigation!UBTTask_FlyTo::ExecuteTask() [g:\engines\unreal\source\ue_4_20\engine\plugins\marketplace\donainavigation\source\donainavigation\private\behaviortree\bttask_flyto.cpp:58]
UE4Editor_AIModule!UBehaviorTreeComponent::ExecuteTask() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\aimodule\private\behaviortree\behaviortreecomponent.cpp:1687]
UE4Editor_AIModule!UBehaviorTreeComponent::ProcessExecutionRequest() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\aimodule\private\behaviortree\behaviortreecomponent.cpp:1448]
UE4Editor_AIModule!UBehaviorTreeComponent::TickComponent() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\aimodule\private\behaviortree\behaviortreecomponent.cpp:1172]
UE4Editor_Engine!FActorComponentTickFunction::ExecuteTickHelper<<lambda_e8384def656dc646af48282ce274db64> >() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\engine\classes\gameframework\actor.h:3095]
UE4Editor_Engine!FActorComponentTickFunction::ExecuteTick() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\engine\private\components\actorcomponent.cpp:797]
UE4Editor_Engine!TGraphTask<FTickFunctionTask>::ExecuteTask() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\core\public\async\taskgraphinterfaces.h:829]
UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\core\private\async\taskgraph.cpp:665]
UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilIdle() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\core\private\async\taskgraph.cpp:585]
UE4Editor_Engine!FTickTaskSequencer::ReleaseTickGroup() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\engine\private\ticktaskmanager.cpp:558]
UE4Editor_Engine!FTickTaskManager::RunTickGroup() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\engine\private\ticktaskmanager.cpp:1455]
UE4Editor_Engine!UWorld::RunTickGroup() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\engine\private\leveltick.cpp:780]
UE4Editor_Engine!UWorld::Tick() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\engine\private\leveltick.cpp:1466]
UE4Editor_UnrealEd!UEditorEngine::Tick() [g:\engines\unreal\source\ue_4_20\engine\source\editor\unrealed\private\editorengine.cpp:1691]
UE4Editor_UnrealEd!UUnrealEdEngine::Tick() [g:\engines\unreal\source\ue_4_20\engine\source\editor\unrealed\private\unrealedengine.cpp:403]
UE4Editor!FEngineLoop::Tick() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\launch\private\launchengineloop.cpp:3495]
UE4Editor!GuardedMain() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\launch\private\launch.cpp:166]
UE4Editor!GuardedMainWrapper() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\launch\private\windows\launchwindows.cpp:144]
UE4Editor!WinMain() [g:\engines\unreal\source\ue_4_20\engine\source\runtime\launch\private\windows\launchwindows.cpp:223]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll

I've dealt with access violation once before, it was due to the pawn being out of the nav volume bounds. It is not the case this time, I made double-sure of that.

UE 4.20.2, Blueprint project
Relevant screenshots: https://imgur.com/gallery/PEV3uwx

[TriConsulting]

This may be a stupid question because this specifies that it is a flying AI system, but is there a way to query the system for land-bound paths and to prevent traversal of steep slopes?
I have a relatively large voxel world with player-spawned structures, and while navmeshes work I am looking for a more optimized approach for NPC movement.
The system would not have to handly many actors at once, pathfinding would only be activated when a player is nearby and actively being chased.

If the system cannot be used in this scenario I would appreciate any pointers for other options.
Thank you!

[Angius]

while navmeshes work I am looking for a more optimized approach for NPC movement.

I don't think voxel based, full-3D navmesh is any more optimized than a regular, tri-based 2D one. Quite the contrary, in fact.

[Reaver47]

Hi VSZ ,
first of all thanks to bring us this amazing plugin, it's awesome.
I used for some tests on 4.18 and it work perfectly, but yesterday i try it on 4.20 and now if a pawn exit from the nav bound and call the FlyTo node in the Behaviour Tree the editor crash with this exception:
Access violation - code c0000005 (first/second chance not available) There is something i can do for fix it? Thanks

[Sitrec]

Hi, any news on a 4.21 version?

Thanks!

[Feng Meow]

Wondering if there's a trick I'm missing in getting the flying unit to navigate correctly to a moving target point, such as the player.

Currently I'm spawning a Target Point at the player's socket location. Then using the FlyTo node to fly an actor, however the actors seem to orbit a random amount of times before straightening out, and I'm wondering if there's a setting I'm missing to have the target point be spawned or moving.

[Cucharón]

Is there any function like AI Move To (I mean in the blueprint, not in the BT)? Or must be programed manually using Schedule Pathfinding Task?

Thank you.

[Tinhauser]

I am trying to figure out if I need this. I need a flying AI that can chase a point in 3D space, this point will be moving, because it’s attached to the player, who is also flying. I don’t need any obstacle avoidance. I would like to use behavior tree.

I have this installed and it can move the AI, but I feel like I want to just have 1 gigantic voxel and disable obstacle avoidance/pathfinding. I only need to go straight and the maps are big (over 100km).

Should I just use waypoints?

[Thunder_Owl]

I am trying to figure out if I need this. I need a flying AI that can chase a point in 3D space, this point will be moving, because it’s attached to the player, who is also flying. I don’t need any obstacle avoidance. I would like to use behavior tree.

I have this installed and it can move the AI, but I feel like I want to just have 1 gigantic voxel and disable obstacle avoidance/pathfinding. I only need to go straight and the maps are big (over 100km).

Should I just use waypoints?

You just need to give that AI flyer direction vector to player (or point attached to player) all the time. Like in picture. You can add speed changes depending on distance if you wish, also some "too close" distance limit check (not in pic):