Object disappears when hand touches it

Tags: #<Tag:0x0055579a29f878> #<Tag:0x0055579a29f620>

coldfusion64 2016-09-03 10:07:10 UTC #1

Hi everyone, I am a beginner in this community and trying to integrate leap motion control using Unity. I am encountering this specific error message - "Rotation quaternions must be unit length" when I am trying to grab or touch the object. What should I do? TYVM

Joe_Ward 2016-09-03 20:13:10 UTC #2

Can you describe your setup in more detail? Are you running any scripts when the hand touches and object? How is the object configured? Which hands are you using? etc.

coldfusion64 2016-09-04 05:18:51 UTC #3

Hello there, I'm trying out the new Interaction Engine. As far as I am aware I dont have any particular scripts running aside
from the Leap Motion Scripts. I'm using the InteractionCube for the object. LoPloy_Rigged hands and the brushhands for my hands

Joe_Ward 2016-09-04 20:19:17 UTC #4

Does the same error occur in the Interaction Engine example scene?

We have some documentation on setting up a scene with the Interaction Engine here: https://developer.leapmotion.com/documentation/unity/unity/Unity_IE_Setup.html

The error could mean that something hasn't been initialized properly (thus trying to calculate a rotation with a zero-length quaternion).

coldfusion64 2016-09-07 06:45:46 UTC #5

So I tried a new Scene while following the Instructions. So heres the error when trying to touch the object

Rotation quaternions must be unit length.
UnityEngine.Rigidbody:set_rotation(Quaternion)
Leap.Unity.Interaction.ActivityMonitorLite:UpdateState() (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionBehaviours/ActivityMonitor.cs:67)
Leap.Unity.Interaction.ActivityManager:UpdateState(Frame) (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionBehaviours/ActivityManager.cs:166)
Leap.Unity.Interaction.InteractionManager:simulateFrame(Frame) (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionManager.cs:750)
Leap.Unity.Interaction.InteractionManager:FixedUpdate() (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionManager.cs:645)

Joe_Ward 2016-09-07 17:46:47 UTC #6

I cannot duplicate the error, either in a new scene or an existing scene, so it is impossible for me to know what has gone wrong in your scene.

james87 2016-09-12 23:58:07 UTC #7

Hi there

I also have this issue, I find that it seems to be related , at least in my case, to the interaction behaviour objects being a fair distance away from the scene origin. This happens even in the example scene if you move all game objects in the scene away from the origin. As well as the quaternion error I also get the following.

Explosion was detected! Object InteractionCube (3) (UnityEngine.GameObject) has been reset to its previous state. If this was intentional movement, make sure you have called NotifyTeleported on the InteractionBehaviour, or raise the explosion velocity threshold.
UnityEngine.Debug:LogWarning(Object)
Leap.Unity.Interaction.ActivityMonitorLite:UpdateState() (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionBehaviours/ActivityMonitor.cs:60)
Leap.Unity.Interaction.ActivityManager:UpdateState(Frame) (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionBehaviours/ActivityManager.cs:166)
Leap.Unity.Interaction.InteractionManager:simulateFrame(Frame) (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionManager.cs:750)
Leap.Unity.Interaction.InteractionManager:FixedUpdate() (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionManager.cs:645)

Joe_Ward 2016-09-13 00:42:08 UTC #8

Hi James,

We found and fixed the bug that (I believe) you submitted to developers@leapmotion.com. You can find the fix at our github site: https://github.com/leapmotion/UnityModules/blob/develop/Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionBehaviours/ActivityMonitor.cs

Replace your existing ActivityMonitor script with the one here.

Thanks for the report! The key to reproducing the problem was moving everything away from the origin by more than 10 meters.

james87 2016-09-13 00:56:27 UTC #9

Hi Joe,

I did indeed. Thanks so much! Works fine now. You guys are quick haha.

Regards

James

vivek161993 2017-07-04 07:22:28 UTC #10

Hi everyone,
I am also having the explosion issue with leap motion and the link that was given as solution is no longer valid, so can you provide that link again.

By the way here is what I am getting in logs

Explosion was detected!  Object C(Clone) (UnityEngine.GameObject) has been reset to its previous state.  If this was intentional movement, make sure you have called NotifyTeleported on the InteractionBehaviour, or raise the explosion velocity threshold.
UnityEngine.Debug:LogWarning(Object)
Leap.Unity.Interaction.ActivityMonitorLite:UpdateState() (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionBehaviours/ActivityMonitor.cs:60)
Leap.Unity.Interaction.ActivityManager:UpdateState(Frame) (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionBehaviours/ActivityManager.cs:166)
Leap.Unity.Interaction.InteractionManager:simulateFrame(Frame) (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionManager.cs:750)
Leap.Unity.Interaction.InteractionManager:FixedUpdate() (at Assets/LeapMotionModules/InteractionEngine/Scripts/InteractionManager.cs:645)

alexmarcolina 2017-07-07 03:43:13 UTC #11

That error is actually part of the older version of the Interaction Engine, if you update to the new version of the interaction engine, that should fix the error you are encountering.

You can check out this page here to grab a download of the newest version of the interaction engine:
https://developer.leapmotion.com/releases

You can grab the 1.0.1 version which is brand new and has a lot of new features, but keep in mind it has been re-written and is not backwards compatible.

If you need backwards compatibility, you can download version 0.3.1