How to Make Physics-Based Hands in Unity XR 

For anyone who has issues with hands randomly flipping 180 degrees or flipping when turning the hand(Over-turning), this is the fix for the script(Adds checks for rotation): private void PhysicsMove() { // Position var positionWithOffset = _followTarget.TransformPoint(positionOffset); var distance = Vector3.Distance(positionWithOffset, transform.position); _body.velocity = (positionWithOffset - transform.position).normalized * (followSpeed * distance); // Rotation var rotationWithOffset = _followTarget.rotation * Quaternion.Euler(rotationOffset); var q = rotationWithOffset * Quaternion.Inverse(_body.rotation); q.ToAngleAxis(out float angle, out Vector3 axis); if (Mathf.Abs(axis.magnitude) != Mathf.Infinity) { if (angle > 180.0f) { angle -= 360.0f; } _body.angularVelocity = axis * (angle * Mathf.Deg2Rad * rotateSpeed); } }

I fixed the hands a little, I added a time.deltatime to body.velocity = (positionWithOffset - transform.position).normalized * followSpeed * distance * Time.deltaTime; and body.angularVelocity = angle * axis * Mathf.Deg2Rad * rotateSpeed * Time.deltaTime; . that made the hands more stable, but the hands were moving too slow so I changed Follow speed to 1800 and rotate speed to 6000. You also should move the player inside XR rig so if you walk around the hands are more stable.

Bro, thank you for all these videos, I've been working with Unity for 4 years now, and recently got a Quest 2 and wanted to start developing for VR, your videos are super helpfull. Thanks again!

i hope you upload that next video, i really need to know how to not make my hands just phase through objects. AWESOME VIDEOS bro keep up the work

Will look forward to part 2!

What video/tutorial do you want to see next?! Reply to this comment and let me know! 👇

No clue, if people are having issues with this, but the adding the absolute offset didn't quite match the correct position for me. The position only matched at a specific controller position and rotation. So to calculate the correct target position, I used "Vector3 targetPos = _followTarget.TransformPoint(positionOffset)" , where positionOffset is the local offset to the hands from the controller. TransformPoint calculates the world position from a local position.

Download the Project (for FREE): www.vrcreators.io/codedownloads

10:44 what's the point of calculating the vector between the position of the gameobject (transform.position) and the position of the target in line 58, and then normalizing it if it's to remultiply it by its distance behind that we calculated in line 57. Because then we find the non-normalized vector if we multiply it by its distance

Really need a part 2

i have looked for tutorial like this for sooooooo long. you have saved me! thanks a lot

Hi Justin, thanks for the detailed Video. I'm using oculus integration sdk and in my ovrhands, i have attached colliders and the tracking works really well. However, I am unable to manage grab and other interactions like earlier.

Awesome bro! i use my own 3d hand models and it works just fine! i had one little issue in the other tutorial on how to animate the hands. i did everything but it just didn't work for some reason. but i fixed it i just watched an other tutorial and then i came back to this tutorial. im exited for the hand pose tutorial for when you grab objects! see ya soon

I have no idea if I'll get a response, but I got an issue that came from this. I followed all the tutorials about getting the hands to be rotated correctly. After adding the physics, the hands will not rotate correctly, regardless of what I do in the inspector. Any help would be appreciated, the code is almost identical to this video outside of some minor changes. Plus the code for the physics grab.

I had a trouble when I tried to attach the hands to the controllers,. It was solved when I replace the Update() function with FixedUpdate() function. BTW, Thanks for the great videos with super high quality!!

Love the tutorials! I'm having one slight issue though and I'm not sure if I did something wrong. The rotation seems to be too slow and if I turn my hand relatively fast its very obvious that the rotation is slow. I have all the same variable values but the hand still seems to rotate too slow. If I turn up the rotation speed I get the vibrating that you talked about. Thank you!

Haven't watched all your videos yet. Has the second part of this come out?

Great content man, thanks!

I'm in the works of learning VR game design using all of your tutorials and loving them!! Having a slit issue with floats converting the vector3 with this exact code. Would you have any idea on how to get around this issue?

For some reason when I click in the hierarchy to go to prefabs and unpack the XR Rig. Prefabs does not show up. It’s very strange, I don’t know what I’m doing wrong or what the issue is. These tutorials are awesome though! Keep up the good work!

The distance is calculated between the followObject and the transform.position. But the relative ration is calculated between the followObject and the _body. Shouldn’t these two be consistent in using the same pair?

I can't seem to find the additional videos for physics hands

Great tutorials :)

Thanks for the tutorials. They help a lot! I am having an issue where the hands are not rotated properly to match the controller rotation, EVEN if I rotate them or the controllers in the editor. Can you help me with this? Thanks!

Hey Justin, how would you combine this with ik

I've just followed this tutorial but now my hands don't animate or pick up objects from the last tutorial :( What have I done!? Also love the tutorials thank you for helping me learn!

Just tried this out, one issue I've run into is that when I'm rotating my left hand when it hits a certain degrees it rotates the opposite direction till it reaches where I was, any fix for that?

Is this still nessacry relevant to your 2022 video where the hands are children of the controllers I'm running into a lot of issues after following that video and then onto this one do i need the follow and rotation if they just stay as children under the controller

Hey man are you ever going to make procedurally animated hand tutorial?

Hi there, great video! Everything works fine except for one small thing: when the hands collide with a box collider they take a lot of time to return the right position (the follow target one) any idea to solve this?

my hands are jittering alot can you help me with this

Did the second video come out about objects in your hands?

Could this be used to interact with other humanoid models? For example if you had a human model with a rig (from blender) and an animation where said human tried to punch you, could you effectively grab its arm as if you were fighting against it to stop it punching you?

If you feel like your hands are rotating too slowly, remember to set the "rigidBody.MaxAngularVelocity" to a higher number. i believe default is 7.

Great video. So, second part :P?

hey how do i stop hands going thought walls

How to get the velocity of Left and Right from controller movement ? Action mapping gives zero every time, except one but it's velocity tracking from either controller.

At first, thanks for your tutorials. I animated the hands with your older video and tried to implement the physics from this video. The physics work for the most part but the animation is gone. How can i add the animation again?

I tried making these hands, and the hands are far away from the actual controllers, and the hands float up and down slowly like 0 gravity, and sometimes they collide they start flying everywhere, but the controlling of the hand kinda works Edit: Fixed it.

hi will coilder stop them going thought objects walls without the other code

why you just don`t use XR Direct Interactor for Physics?)

Looking forward to the next part, great stuff!

how did you do it can you share with me , thank you

Instead of moving with the controller positions, my hands just fly away. Any solution to this?

for curiosity, would it still work if i just added the collisions but , keeping the normal Xr control of the hands ?

Why not have each hand just have a mesh collider so you don't have to do each part of the hand?

anyone willing to discord and help me on screenshare, i have nearly it just struggle with the animation. is there no way to just import it :(

Is there a way to like skip over the animation part?

anyone else having issues not being able to move after this tutorial? the hands move, but only about .01 units before stopping. any help?

video worked great! but i do have some bugs i was hoping you could help with, im using a locomotion system which does continuous moving and turning, but if i try and move forward my hand gets in the way, meaning i either have to stretch my arm out so i can move forwards or just live with the fact i cant move forwards, also my hands sometimes collides with my own body from the xr rig, meaning it launches me out of the map, i also had this problem with my grab-able, which is a sphere, any help?

I have problem,my hands are shaking a little everytime

Hey, there's a good chance you will not have time to read this but If you do, I would like to see a tutorial on stabbing in vr. I 100% understand If you won't be able to do one.

just commenting for the algo. Thanks, m8!

the most important part of any vr game is to have a Rigidbody controller with NO Translate, No Transform, only AddForce or .Velocity.