Dynamic Obstacle Avoidance

Hello!

I released new package on Asset Store. Its Dynamic Obstacle Avoidance package.
Its usefull for using on npc characters, movable objects without nav mesh carving and behaviour that need local avoidance.


Here is demo video:

... and here is link to demos so you can test how it works.
DEMO/S

Usage:
In this demos I made it so chracters can push objects if there is no other way of traversing through obstacle but you assign high repulsion value so characters will not go near. It all depends how you tweek certain object.
Also you can assign character more persistance value in path following so it will more likely to go through obstacles or asssign lower persistance to make them less likely to go through.

You can get it at: AssetStorePage

Thank you !

 

WOW nice asset!
How easy is it to add the obstacle avoidance to mercenaries/fallowers or enemy that is already in an RPG project???

 

Hello,
On objects all it takes is to put 'Obstacle' component on it

On npcs, you have to implement IAvoider interface and
add:
' ObstacleManager.CalculateObstacleAvoidance(ref move, this);'
after all movement ( after path is calculated, being it NavMesh or other )

There is also an option to smooth npc avoidance if you like.
For that you can copy code from examples which is between SMOOTH_MOVEMENT macro.
Look at the _add_local_avoidance() method, its the main one.

Note that in some npc scripts I set movement y to zero because npcs are walking on ground and physics is responsible for Y axis movement ( jumping, falling )
But you dont have to do that if npc if flying.

 

I definitely need this for all my fallowers/mercenaries and enemies, hope this helps make them smarter..
Thank You..

 

And did it help?

Can anyone tell how well it works with ai agents controlled by mecanim?

I'm making my mecanim agents move via:

Code (CSharp):

1. ai.navAgent.speed = (_animator.deltaPosition / Time.deltaTime).magnitude;

Does it make any difference how the NavMeshAgent is controlled or do I need to rewrite some code?

 

Not sure yet, still have one more question to ask the developer.

 

Hi, I have one more question if you don't mind. Will this support automatic integration with an existing movement system script that is already being used on an enemy???

Thank You again..

 

It doesn't matter what movement calculations you are using as long as you put avoidance method/s last ( after movement)
It takes existing movement vector ( velocity ) and modify it to take avoidance into account.

 

Allright sir, I'm making my purchase today..

 

Please let us now how it goes. I just can't get it to work with mecanim (without root motion).

This is how I handle the ai movement:

Code (CSharp):

1.  
2. void OnAnimatorMove() {
3.  
4.      RotateTo(orientationDir);
5.  
6.      Vector3 localDesiredVelocity = transform.InverseTransformDirection(navAgent.steeringTarget - this.transform.position).normalized * movementSpeed;
7.  
8.      animator.SetBool("Move", (Arrived() == false));
9.  
10.      navAgent.speed = (animator.deltaPosition / Time.deltaTime).magnitude;
11.  
12.      animator.SetFloat("X", localDesiredVelocity.x);
13.      animator.SetFloat("Z", localDesiredVelocity.z);
14. }

What would be the best way to integrate the avoidance velocity? Sorry I just can't get my head around this.

 

Hi,
Ok, try this:
get world move direction which is:
Vector3 direction= (navAgent.steeringTarget - this.transform.position).normalized.
After that add ObstacleManager.CalculateObstacleAvoidynce( ref direction, this);
Then you'll get modified direction for avoidance.
And than you can continue like you do:

Vector3 localDesiredVelocity = transform.InverseTransformDirection(direction).normalized * movementSpeed;

animator.SetBool("Move", (Arrived() == false));

navAgent.speed = (animator.deltaPosition / Time.deltaTime).magnitude;

animator.SetFloat("X", localDesiredVelocity.x);
animator.SetFloat("Z", localDesiredVelocity.z);

 

Thanks, this helps. Now the actors are at least playing the correct directional move animations, however they still move along the path without avoidance. I think it's because the avoidance velocity isn't added to the actual navmeshAgent velocity which moves the ai? I've looked through the example scripts but couldn't find anything helpful for my case. Can you tell me what I need to add?

 

In the start or awake method set navAgent.updatePosition = false;
now calculate path manualy:
create this method:

Code (CSharp):

1.  
2. NavMeshPath path;
3.         protected bool calculate_path(NavMeshAgent navAgent, Vector3 destination, ref Vector3 moveDirection)
4.         {
5.             if (path == null) path = new NavMeshPath();
6.  
7.             Vector3 transformPosition = transform.position;
8.             if (!navAgent.CalculatePath(destination, path))
9.                 return false;
10.  
11.             if (path.status != UnityEngine.AI.NavMeshPathStatus.PathComplete)
12.                 return false;
13.  
14.             if (path.corners.Length < 2)
15.                 return false;
16.  
17.  
18.             Vector3 currentWaypoint = path.corners[1];
19.             Vector3 toTarget = currentWaypoint - transformPosition;
20.             moveDirection += toTarget.normalized;
21.  
22.             return true;
23.         }
24.  

now change code with this:
Vector3 movement = Vector3.zero;
calculate_path(navAgent, DESTINATION_VECTOR, ref movement); // calculating nav mesh path
ObstacleManager.CalculateObstacleAvoidance(ref movement, this); // adding avoidance

rest like it was:

Vector3 localDesiredVelocity = transform.InverseTransformDirection(movement).normalized * movementSpeed;

animator.SetBool("Move", (Arrived() == false));

navAgent.speed = (animator.deltaPosition / Time.deltaTime).magnitude;

animator.SetFloat("X", localDesiredVelocity.x);
animator.SetFloat("Z", localDesiredVelocity.z);

 

Thank you for your help! I did what you posted but can't get it to work. Now the navagent moves but the animator avatar won't follow, it's keeping its initial position doing animations and turning like it's supposed to but not changing position.

I'll study the example scripts some more, maybe i'm overlooking a simple thing.

 

Oh yes, your character was moved by nav agent.
Lets try implement root motion controlled by script in OnAnimatorMove method
Add this code in OnAnimatorMove():

Code (CSharp):

1.      
2. if (Time.deltaTime > 0 )
3.             {
4.                 Vector3 v = (m_Animator.deltaPosition * moveSpeedMultiplier ) / Time.deltaTime;
5.            
6.  // IF USING RIGIDBODY
7.                 if (m_Rigidbody)
8.                 {
9.                     if (m_Rigidbody.isKinematic)
10.                         transform.position += v * Time.deltaTime;
11.                     else
12.                     {
13.                         if (m_Rigidbody.useGravity) v.y = m_Rigidbody.velocity.y;
14.                         m_Rigidbody.velocity = v;
15.                     }
16.                 }
17.                 // ELSE
18.                 else
19.                 {
20.                     transform.position += v * Time.deltaTime;
21.                 }
22.             }
23.  

Just make sure that Root Transform Position ( XZ )is not baked into pose.

Im my script 'CharacterObstacleAvoidanceAgent' you can see how I implemented NavMeshAgent and obstacle avoidance.
Disabling NavMeshAgent update, calculating path manualy ( like here ) and moving character by root motion by script.
Look in 'CharacterObstacleAvoidanceAgent.cs' and 'ThirdPersonCharacter.cs'

 

Thank you very much for your time. The thing is that I try to avoid rootmotion because the movement is too unprecise for my project.
That's why I decided to go with something like:

Code (CSharp):

1. navAgent.speed = (animator.deltaPosition / Time.deltaTime).magnitude

Sorry I should have mentioned this before.

But with all you posted I can make DOA easily work in my other non-mecanim projects. Thanks for your help and this great asset!

 

i also dont use root motion, just the navmeshagent using the animator deltaposition like is show in the previous post. I dont have clear if it works with this solution.

 

To use on NavMeshAgent you have to find the way to modify agent's position to include avoidance direction.
I did it by using NavMeshAgent.nextPosition.

I'll update the package with example of it.

 

Was looking at this package and it looks great, do i need to use navmesh with this, or can they handle basic tracking and avoidance without it?

 

No nav mesh not required.
Examples are using nav meshes but I can be used without it.
Core obstacle avoidance do not take nav mesh into calculations.

 

Hello,

I am working on a 3d rpg, which has a landscape just made of chunks and each chunks contains blocks (like Minecraft... but with 45° slopes).
Each chunk has one collider and one mesh where many blocks are "melted" together.

So I cannot add a "Obstacle" script to each block, but I could add it to each chunk? Would this be possible or is it to slow then and not detecting ground anymore etc?

Or can it just works using raycasts and "all in one" chunk colliders?

Thanks a lot! This Looks very interesting

 

Obstacle does not need to have collider attached.
It can detect object by point ( position of object ), sphere ( position + radius ) or line ( two points ) and it calculates avoidance by those values.
You can add Obstacle to all blocks or you can add on runtime when needed to object which needs it.
Just remember to add newly created obstacle to ObstacleManager.obstacles list

 

excellent thanks, is this usable for voxel terrains and navigating around walls and under caves (if they can see) or is this too much for this system?

 

Hmmm, It can avoid convex shapes. This is not a pathfinding system.Its meant to work along with or without pathfinding systems.

 

Hello,

I released an update in which I added an example on how to use avoidance with Unity's nav mesh agent.

Thx.

 

Just bought it. I Test it by myself, the NPC is jitter and rotating like a fool, I can't find the reason.

 

Can you be more precise?
Is it problem with any demo scene?
What type of character is causing you problems - one with nav mesh agent or one without ?
Is creating new bot is causing problems?
Does it show any errors?
...

 

Hello, I have just purchased your component, thank you I am making good progress.

May I ask two questions please...

1. How can I tell when my NPC has "arrived" at Target (I am not using navmesh or anything) ?

2. How can I move my agent. I am not using physics or rigidbody or velocity as in your BasicObstacleAvoidance example, just a simple cube I want to move and rotate in the correct direction on the way to the Target.

thanks again and best wishes from Australia

John

 

Hi,

1. Your NPC is 'arrived' if your NPC distance to target is lesser or equal to assigned range.
In 'BasicObstacleAvoidance' that is 'waypoint distance' variable.

2. You can move your agent by assigning direction ( plus speed ) to current position.
So, calculate direction and, before you add to NPC position, let direction go through obstacle avoidance calc.
( ObstacleManager.CalculateObstacleAvoidance(...); ) which will give you modified direction.

There is example of this in 'BasicObstacleAvoidance.cs'.

 

Hello
Is your asset can help resolve problem with my units bashing from behind from those stopped to fire??
Entire problem described in this thread:

https://forum.unity.com/threads/how...cal-avoidance-asset-suggestion-maybe.1025272/

 

Hi,

I created this to resolve that kind of problems.
But to be sure, maybe best thing for you is to try demos and see if it is the behaviour you are looking for.

Thank you!

 

I already tried behaviour in follow example and it is what i look for.
But can you precise if i must interfere much into my project using your asset? It is something i can add to my agents and they start to properly avoid each other?

 

Well, I would say not much.
Unity NavMesh is not needed - there are examples in project where I set dynamic avoidance move.Y result to zero to make object use navmesh y position. You dont need to do that if in space for instance.
Avoidance is calculated last and you can apply to your existing moving velocity.

 

Hey,
I have the same question as @Tomasz_Pasterski, i have a npc that uses navmesh, how hard is it to implement this with my character, is it a matter of adding a component to the character and it will avoid, or will it be necessary to adjust the code of my npc to implement the avoidance?
Another question is, must be added the obstacle component to every object desired the npc to avoid or is there a layer allowing the npc to avoid objects with selected layers?

Thank you!

 

See my video, this just doesn't work as advertised.

 

Hello,
I didnt see you created nav mesh on new scene you copied the contents of test scene.
Bots use nav mesh to walk on.

Also there is some documentation in docs folder.

 

Too late, i bought it 2 days ago, but thanks.
@username_unity_of_my, i'm having a problem with the detection. When the character happen to go in the same direction (wich in my case happens alot) and the detection kicks in, the characters just stick together and keep going and going in the average direction of both, never evading one from the other.
If the explanation is not understandable i can send a video.
Can you do something about this?

Thanks!

 

That usually happens when there is no zero friction material set on the character collider.
Did you put zero friction mat on characters?
Also a randomizing small differences in stats would help against that. ( So bots dont have exactly the same avoidance parameters )

 

They actually had no material at all. Changed it to zero friction on all npc's and it keeps the same.
It seems to me that the avoidence direction cross one another, and they keep avoiding, but since they are colliding, they keep moving in the same direction colliding with one another.

 

Try to randomize small differences in parameters. Also make their move speed not exacly the same. That should prevent that kind of behaviour.
But if you want to make sure that never happens, make a script that will keep changing parameters by small amount. That way, even if their paths do come to deadlock, they will part ways upon parameter change.

 

Wich parameters should i randomize?
distance, angle, strength, power and persistance?

 

Tried that and not working. It has in fact worsened it... :\

 

Ah ok, will look into it. Btw, my scene is gonna be entirely procedural, generated at runtime, will this still work?

On the docs it doesn't tell me to create a navmesh

 

@Milionario it is possible to generate a navmesh at runtime therefor it shouldn't be a problem.
Just make sure you generate the navmesh after generating the environment.

https://learn.unity.com/tutorial/runtime-navmesh-generation#5c7f8528edbc2a002053b492
These are also on youtube

 

Do you know how to change the size of a navmeshsurface during runtime? I tried modifiying its properties
GetComponent<NavMeshSurface>().center = transform.position;
GetComponent<NavMeshSurface>().size = new Vector3(1, 0, 1);
But it doesn't change, it still bakes navmesh for the entire scene.

 

I added a Debug.Log if UnityEngine.AI.NavMesh.CalculatePath returns false on BasicObstacleAvoidance, it is still failing, but i do have the navmesh on my scene

 

... also you can randomize move speed.
Just remeber that parameters are very sensitive so change very little.
Although I think changing move speed should be enough.

 

Actual avoidance calculations dont use nav mesh but that demo scene does.
I just set avoidance velocity result y to zero so that bots use y from physics collider.

 

The BasicObstacleAvoidance does use navmesh because it requires UnityEngine.AI.NavMesh.CalculatePath to calculate the path to the destination.

I am considering asking for a refund on this since its really not clear on how you implement it on a blank scene and there is no easy way to plug this in your project

 

I tried that after trying randomizing all of the parameters, and isn't working either. Lowering the angle to 45 is what seems to work the best.
The problem is that this way the npc's collide when avoiding each other with that angle.

With the angle greater than that they enter the deadlock...