How do I get a position from a detected ObjectInstance?

Question

I have been trying to follow what's in https://learn.microsoft.com/en-us/azure/object-anchors/concepts/sdk-overview with some success. I successfully detect an ObjectInstance, but how do I get the coordinates to place my GameObject in the matching position? There are a lot of unfamiliar concepts to me in the documentation like SpatialGraphCoordinateSystem and I am at a loss on how to take it further.

Update

I finally got it working by first converting the SpatialGraphCoordinateSystem to SpatialCoordinateSystem.

SpatialGraphCoordinateSystem coordinateSystem
[...]

//After getting an ObjectInstance instance
SpatialCoordinateSystem spatialCoordinateSystem = instance.TryGetCurrentState().Center.ToSpatialCoordinateSystem();
var instancePos = spatialCoordinateSystem.TryGetTransformTo(coordinateSystem.Value.ToSpatialCoordinateSystem()).Value.ToUnityLocation().Position;
var instanceOrientation = spatialCoordinateSystem.TryGetTransformTo(coordinateSystem.Value.ToSpatialCoordinateSystem()).Value.ToUnityLocation().Ori;

//Place my hologram on the detected position
mySphere.transform.SetPositionAndRotation(instancePos, instanceOri);

Answer 1

In reading your question above, I think based on what you are asking, you are needing to call this: ObjectInstance.TryGetCurrentState Method (Microsoft.Azure.ObjectAnchors) | Microsoft Docs

This will return an ObjectInstanceState with a center property that is a SpatialGraphLocation Struct (Microsoft.Azure.ObjectAnchors.SpatialGraph) | Microsoft Docs

The SpatialGraphLocation will have the pose information that you are looking for.

If you have questions on Coordinate Systems in general in Mixed Reality, I'd suggest you start here to learn more: Coordinate systems - Mixed Reality

Another good resources on AOA, if you haven't looked at the sample already, is available here: https://github.com/Azure/azure-object-anchors

There is also a tutorial that walks through this sample here: Quickstart: In-depth MRTK walkthrough - Azure Object Anchors | Microsoft Docs