The Mixed Reality Forums here are no longer being used or maintained.
There are a few other places we would like to direct you to for support, both from Microsoft and from the community.
The first way we want to connect with you is our mixed reality developer program, which you can sign up for at https://aka.ms/IWantMR.
For technical questions, please use Stack Overflow, and tag your questions using either hololens or windows-mixed-reality.
If you want to join in discussions, please do so in the HoloDevelopers Slack, which you can join by going to https://aka.ms/holodevelopers, or in our Microsoft Tech Communities forums at https://techcommunity.microsoft.com/t5/mixed-reality/ct-p/MicrosoftMixedReality.
And always feel free to hit us up on Twitter @MxdRealityDev.
World anchor sharing with UNET
raj
✭
Hi,
I've been trying to share world anchors across HL devices with UNET so that there is no need for a separate machine for "hosting". I'm trying to do simple head tracking like the one in HL toolkit sample testscene. So far here's where I'm at.
Similar to the ImportExportAnchorManager I have my own class creating the byte array that needs to be shared across using WorldAnchorTransferBatch class.
Anchor blob generated is received at the other end and I'm getting import complete too. But the holograms are not where they are supposed to be. I saw that InverseTransform of the point is being passed in the HoloToolkit sample for head tracking. Really didn't get why we have to do that. But tried that as well. No luck. Is there anything more that I should be doing ?
Best Answer
-
There is a Position (Vector3) and Orientation (Quaternion) for the anchor.
Calculate relative position from anchor as:
Vector3 relativePosition = anchor.InverseTransformPoint(position);Calculate relative orientation from anchor as:
Quaternion relativeOrientation = Quaternion.Inverse(anchor.transform.rotation) * rotation;Send to clients or peers via your favorite networking protocol
On the client use the relative position and rotation to calculate where and in what orientation the object should be.
Calculate position from anchor and relative position as:Vector3 position = anchor.transform.TransformPoint(relativePosition);Calculate orientation from anchor and relative orientation as
Quaternion rotation = relativeOrientation * anchor.transform.localRotation;I would love to hear how it goes using the Shared WorldAnchors. I have it on my list to try.
5
Answers
Just wanted to add some additional info
I'm using UNET HLAPI for this. I'm thinking of leveraging unity's network transform components to sync transforms. And head objects are the player objects in the network.
There is a Position (Vector3) and Orientation (Quaternion) for the anchor.
Calculate relative position from anchor as:
Vector3 relativePosition = anchor.InverseTransformPoint(position);Calculate relative orientation from anchor as:
Quaternion relativeOrientation = Quaternion.Inverse(anchor.transform.rotation) * rotation;Send to clients or peers via your favorite networking protocol
On the client use the relative position and rotation to calculate where and in what orientation the object should be.
Calculate position from anchor and relative position as:
Vector3 position = anchor.transform.TransformPoint(relativePosition);Calculate orientation from anchor and relative orientation as
Quaternion rotation = relativeOrientation * anchor.transform.localRotation;I would love to hear how it goes using the Shared WorldAnchors. I have it on my list to try.
You are right. My issue was that I was expecting UNET NetworkTransform Component to track the placement in all the clients. This conflicts our interest that position of an object on each client should be updated with respect to their imported anchor.
So far I've got sharing working with UNET alone. There's no need for additional services now.
@raj
Is that possible to share your project using UNET alone via GITHUB without sharing services? This will be a great help. Thanks
Most of what you said is good stuff and got me on the right track, but the relativeOrientation and anchor.transform.rotation are in the wrong order for the 'decoding' on the receivers end. The *-operator for Quaternions is not commutative.
The correct line would be: Quaternion rotation = anchor.transform.localRotation * relativeOrientation;
I'm not great with rotations in a 3D-world, so I just think of it as having to point in the direction of the anchor, before i apply an anchor-relative rotation.
Sorry for the post-necro, but is the most fitting I found.