About

(Work in Progress)

This StereoKit project implements the XR_FB_spatial_entity OpenXR extensions for the StereoKit library. This enables us to track/persist world-locked anchors on Meta Quest devices! This project is built with the sk-multi template to support cross-platform app development on either Android or Quest+Link platforms.

This project implements the following OpenXR extensions:

• XR_FB_spatial_entity
• XR_FB_spatial_entity_storage
• XR_FB_spatial_entity_query

How to Use in Your Project

Here are the steps on how to use the Meta spatial anchor extension in your StereoKit project.

1. Copy/paste the SpatialEntity directory from this repo into your StereoKit project. It contains all the code to implement the OpenXR extension for StereoKit.

2. Add the SpatialEntityFBExt to your main program file. Note: This code must be called BEFORE calling SK.Initialize.

   SpatialEntityFBExt spatialEntityStepper = SK.AddStepper(new SpatialEntityFBExt());

3. (Optional) Display some UI to interface with the spatial entity system.

   // Spatial Anchor Menu
   UI.WindowBegin("Spatial Anchor Menu", ref window2Pose, new Vec2(30,0) * U.cm);
   if (spatialEntityStepper.Available)
   {
       UI.Label("FB Spatial Entity EXT available!");
       if (UI.Button("Create Anchor"))
       {
           // We will create the anchor at the location just in front of the window (and we'll adopt the UI window's orientation).
           Vec3 anchorPosition = window2Pose.position + window2Pose.Forward * .05f + Vec3.Up * 0.1f;
           Pose pose = new Pose(anchorPosition, window2Pose.orientation);
   
           // We can optionally provide some callbacks for when the async operation either completes successfully or fails.
           spatialEntityStepper.CreateAnchor(
               pose,
               (Guid newAnchorUuid) => Log.Info($"Async anchor creation success. New anchor created: Uuid:{newAnchorUuid}"),
               () => Log.Info("Async anchor creation success failed :("));
       }
   
       UI.SameLine();
               
       if (UI.Button("Load All"))
           spatialEntityStepper.LoadAllAnchors();
   
       UI.SameLine();
   
       if (UI.Button("Erase All"))
           spatialEntityStepper.DeleteAllAnchors();
   
       // List all Anchors
       UI.HSeparator();
       UI.Label($"Anchors Loaded ({spatialEntityStepper.AnchorCount})");
   
       foreach (var anchor in spatialEntityStepper.Anchors)
       {
           // Use a PushId to avoid button Id collisions
           UI.PushId(anchor.Uuid.ToString());
           UI.PanelBegin();
                   
           if (UI.Button($"{anchor.Uuid.ToString().Substring(0,14)}..."))
           {
               // Unselect the anchor (if already selected) or select the anchor (if not already selected)
               if (selectedAnchorId == anchor.Uuid)
                   selectedAnchorId = null;
               else
                   selectedAnchorId = anchor.Uuid;
           }
           UI.SameLine();
           // Button to delete the selected anchor
           if (UI.Button("Delete"))
           {
               spatialEntityStepper.DeleteAnchor(anchor.Uuid);
           }
   
           if (selectedAnchorId == anchor.Uuid)
           {
               UI.Label("XrSpace: " + anchor.XrSpace);
               UI.Label("Located: " + anchor.LocateSuccess);
               UI.Label(anchor.Pose.ToString());
           }
                   
           UI.PanelEnd();
           UI.PopId();
       }
   }
   else
   {
       UI.Label("Spatial Anchor is not available :(");
   }
   UI.WindowEnd();

4. (Optional) Visualize the spatial anchors by looping over them and drawing something!

   // Visualize all loaded spatial anchor
   foreach (var anchor in spatialEntityStepper.Anchors)
   {
   	// Just draw a nice orange cube for the anchor pose
   	Mesh.Cube.Draw(Material.Default, anchor.Pose.ToMatrix(0.1f), new Color(1, 0.5f, 0));
   }

Features not (yet?) implemented

I'd like to get these additional OpenXR extensions up and running as well, when I find the time.

• Implement XR_FB_spatial_entity_sharing
• Implement XR_FB_spatial_entity_container
• Implement XR_FB_spatial_entity_storage_batch
• Implement XR_FB_spatial_entity_user
• Implement XR_FB_scene