Resolved Haptic feedback in XR

Hi,

Is there an explanation of how to achieve haptic feedback in XR.Interaction through a script?

 

+1 I’d like to see an example of this too

 

In XR controller script you will find the below function:

Code (CSharp):

1. public override bool SendHapticImpulse(float amplitude, float duration)
2.         {
3.             if (inputDevice.TryGetHapticCapabilities(out var capabilities) &&
4.                 capabilities.supportsImpulse)
5.             {
6.                 return inputDevice.SendHapticImpulse(0u, amplitude, duration);
7.             }
8.             return false;
9.         }

So assuming you want to call this function from your own script, do like this:

Code (CSharp):

1. private XRController xr;
2.  
3. void Start()
4. {
5.   xr = (XRController) GameObject.FindObjectOfType(typeof(XRController));
6. }
7.  
8. void ActivateHaptic()
9. {
10.   xr.SendHapticImpulse(0.7f, 2f);
11. }

 

I am using Unity version 2020.2.1f1 and the above doesn't work when making a build on Oculus Quest even though it works on the Editor as a Rift using Oculus link. I get zero haptic feedback, any ideas? Does anyone else have the same problem?

 

Yep, exact same behaviour here on Unity 2019.4.11f. Using ADB it seems that InputDevice.TryGetHapticCapabilities returns false on the Quest, but not in editor as Rift.

 

Same problem here. I figured out why.


with OpenXR it doesnt work for me. had to go back to Oculus

 

That would be because, as stated in the Documentation for the OpenXR plugin, Haptics are not currently supported yet.

 

thanks
I adjusted to what I needed, I made another script and implemented it in the righthandcontroller game object which contained the XRController class which was set for the right hand. so i get haptic for hand controller(Right Controller). I replaced: xr = (XRController)GameObject.FindObjectOfType(typeof(XRController));

With: xr = GetComponent<XRController>();

 

Hi, I'm fairly new to XR development. Can someone share a simple script so that I can get a better understanding? I tried following this but I am getting 'XR Controller' not found error. I tried looking into the XR Controller script but I have no idea how to call it's function.

 

I have a tool which could be picked up by either hand, so specifying one controller for haptic didn't exactly make sense. I stumbled upon this way of doing it, which finds whichever controller is holding the object and sends the haptic to that controller.

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.XR.Interaction.Toolkit;
3.  
4. [RequireComponent(typeof(XRBaseInteractable))]
5. public class HapticFeedback : MonoBehaviour {
6.  
7.     public void SendHaptics() {
8.         XRBaseControllerInteractor hand = (XRBaseControllerInteractor)GetComponent<XRBaseInteractable>().selectingInteractor;
9.         hand.SendHapticImpulse(0.4f, 0.1f);
10.     }
11.  
12. }

I'm calling this SendHaptics function from within the activate unityevent on the XRGrabInteractable component placed on the object / tool.

For example, say you have a gun, and it should send haptic when you pull the trigger. This way it works with both hands, and the rumble only happens on whichever hand is holding the gun.

 

Mine is working, but I want the haptics to vibrate like racing heartbeat, with short stops in between vibrations. Is it achievable? I tried playing with the duration and amplitude but it's just the same constant vibration with different strengths that's all :/
Here's my code. Any hints or help would be greatly appreciated!
Cheers.

Code (CSharp):

1. private IEnumerator HapticPattern(){
2.         while(true){
3.        
4.             LeftHand.SendHapticImpulse(0.7f, 1f);
5.             RightHand.SendHapticImpulse(0.7f, 1f);
6.  
7.             yield return new WaitForSeconds(2f);
8.         }
9.     }

 

The class thing

It says class type or script invalid

 

InputDevice.TryGetHapticCapabilities is now returning false with OculusXR plugin in 2021.3.15f
Latest plugins etc: https://github.com/VRStudios/Unity3.../VRstudios/XRInput/API/UnityEngine_XR.cs#L345

 

Yes I'm sure its correct. It seems to only happen with Rift S FYI. Doesn't happen with Quest 2 over link cable.
Identical code used for both. So seems to be an issue with Unity3D or Oculus libs Unity is using.

 

Hey! Ya very possible its on the OVR side & nothing to do with Unity.
Outside a native app though I have no way to confirm this easily.

Unity 2021.3.5f
OculusXR 3.0.2

 

Sorry to dig up an old thread, but we're not able to get Haptics to work at all on RiftS using the above method. Works fine on the Quest2 but not RiftS

We've tried messing with the amplitude and duration, calling the SendHapticImpulse function only once, or every frame, no luck at all. Again, works fine on Quest 2, but not on RiftS (other apps' haptics work fine on the RiftS)

Does anyone have any ideas? Is there something different you need to do for the RiftS controllers?

 

You need to use Oculus APIs directly for it to work well.

Here is an example.
https://github.com/VRStudios/Unity3...Assets/VRstudios/XRInput/API/OculusXR.cs#L138

 

I'd like to add a bump, I'm in Unity 2019.4.6f1 and using XRITK 2.1.1 and OculusXR 1.3.4, and I also get the haptic feedback when I use Oculus Link but don't get it when I actually build the .apk to the Quest. I'm trying to use xrController.SendHapticImpulse(). Any reason this happens?

 

Is there a way to disable the haptic feedback?
I am using xr simple interactable script where I have to enter in hover state, but I would like to disable the haptic feedback. How to do this?

 

You just set values to zero.

 

Sorry to revive this thread again, but I can't seem to get haptic feedback on my PICO 4 controllers. I'm using Unity 2020.3.25f1 and the PICO Unity Integration SDK v2.x.x. I'm also quite new to Unity development and would appreciate some advice!

Essentially, I want haptic feedback that is called on through a method rather than input on the controllers. This is an excerpt from my script. I have my LeftBaseController and RightBaseController assigned in the inspector window but I still can't get any haptic feedback. I know the OnCollisionEnter() is called correctly because I have other visual cues that tell me that it works. Have been trying to solve this for days...

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.XR.Interaction.Toolkit;
3.  
4. public class MoveHelicopter : MonoBehaviour
5. {
6.     public XRBaseController leftController, rightController;
7.     public float defaultAmplitude = 1f;
8.     public float defaultDuration = 1f;
9.  
10.     private void Start()
11.     {
12.         leftController = GetComponent<XRController>();
13.         rightController = GetComponent<XRController>();
14.     }
15.  
16.     private void OnCollisionEnter(Collision collision)
17.     {
18.         if (collision.gameObject.CompareTag("Ground") && !hasCollided)
19.         {
20.             SendHaptics();
21.         }
22.     }
23.  
24.     public void SendHaptics()
25.     {
26.         leftController.SendHapticImpulse(defaultAmplitude, defaultDuration);
27.         rightController.SendHapticImpulse(defaultAmplitude, defaultDuration);
28.     }
29. }

 

Oh nevermind. Seems like restarting the whole setup allowed the haptics to work!

 

FYI from my experience Pico 3/4 have sometimes had haptic or tracking orientation bugs.
Where target haptic controller would always target right controller.
Or tracking velocities didn't match orientation correctly.

Maybe they have been fixed since I last tested though.

 

How do we send buffered haptics via the new input system? I want to have fine-grained control over a haptic FX pattern, but the 'SendHapticImpulse' command is far too simple for this because it can only send a constant amplitude over a fixed duration. I have a byte[] array which contains my haptic pattern, and I want to send that to the controller. It appears that no method exists for XRBaseController.SendBufferedHapticCommand.

I actually tried to implement it myself via the following code where I am converting a Unity animation curve into a haptic buffered rumble byte[] array.

Code (CSharp):

1. public void DebugSendBufferedRumble(AnimationCurve hapticAnimationCurve)
2. {
3.     if (xrController.hapticDeviceAction.action.activeControl?.device is XRControllerWithRumble rumbleController)
4.     {
5.         byte[] bufferedRumbleBytes = AnimationCurveToBufferedRumble(hapticAnimationCurve);
6.         var bufferedRumbleCommand = SendBufferedHapticCommand.Create(bufferedRumbleBytes);
7.         rumbleController.ExecuteCommand(ref bufferedRumbleCommand);
8.     }
9. }

but when I execute the above code, the controller doesn't vibrate at all (I'm using Quest 3 controllers and testing in the Unity Editor via Quest Link). I've verified my byte[] array for the haptic effect is indeed filled correctly. But the controller doesn't vibrate. Is this a missing feature? @VRDave_Unity @chris-massie Or am I approaching this problem the wrong way?

Following a similar pattern to the above, this code works just fine to send a haptic impulse:

Code (CSharp):

1. var command = SendHapticImpulseCommand.Create(0, 1.0f, 0.25f);
2. rumbleController.ExecuteCommand(ref command);

But this code does not work at all to vibrate the controller via buffered rumble:

Code (CSharp):

1. byte[] bufferedRumbleBytes = AnimationCurveToBufferedRumble(hapticAnimationCurve);
2. var bufferedRumbleCommand = SendBufferedHapticCommand.Create(bufferedRumbleBytes);
3. rumbleController.ExecuteCommand(ref bufferedRumbleCommand);

 

Hey @chris-massie, thanks for your response!

I'm wondering if I could get your feedback about something: I ended up creating my own "pseudo-buffered haptics" system that converts a Unity animation curve into a bunch of rapid haptic impulses that get played every frame. It feels sort of "hacky" but it seems to work fine (at least for Quest controllers).

Specifically, the haptic effect is created by constructing a Unity animation curve in the inspector, and then the haptics manager samples this curve every frame to get the current amplitude/intensity over time, and in a coroutine it sends a short-duration haptic impulse every frame at the correct amplitude. I suppose this could be considered a "streamed haptic". I found that any new haptic impulse overrides a currently-playing impulse (at least this is the behavior on Quest). So essentially you can "blast" the controller with haptic impulses every frame in order to achieve a dynamic haptic effect.

Using this system, the duration of each haptic impulse needs to be at least as long as the frame time (so in 90Hz mode each impulse would be 0.01111 seconds long). But I found that it's best to use some "overlap" otherwise you feel an occasional stutter since the transmission of each impulse isn't perfectly timed. I went with a duration of 0.3333 seconds for every impulse, every frame. The extra time gets overridden by the impulse that plays on the next frame, so the overlap covers up any stutters or when the app experiences a drop in FPS.

Is this sort of system viable for production? It seems to work perfectly for Quest controllers, but is this behavior consistent for other hardware? Specifically, will the most recent haptic impulse override any currently-playing haptic impulse for all XR controllers/hardware? I haven't had the opportunity to test this setup on Vive wands, Index, PSVR, or Vive Focus 3 controllers.

P.S. - Someone else had a similar question here, but it was never answered.

 

Hey @chris-massie, thank you for your reply! I'm glad to hear the system I built was the "right way" to do it.

I'm using the Oculus Plugin currently (although I use OpenXR for PC builds from the same project) and the Oculus Plugin appears to act the same way as described in the OpenXR docs, where the most recent haptic event interrupts a currently-playing haptic.

So, this system should work for now! Although I would love to have greater control over haptics in the future, especially since Meta has developed new haptic technology for the Quest 3 controllers. I hope that the OpenXR spec eventually gets updated to support this. At least for now I can use haptic impulses tied to an animation curve in order to give haptic effects some "texture".