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The phenomenon of the object going wrong

The project we're currently using is 0.23, and when we look at the object from the front, back, left, and right, it's anchored normally in the front

Other than that, anchoring does not work normally

I feel a sense of distance and I'm pushed in the direction I see

The same problem occurs when tested in version 0.23 and version 0.21

I'm making the following assumptions - please clarify if they are wrong

  • You're using Think Reality A3
  • You are using Anchors to place the cube directly on the physical cube
  • The virtual and physical cube do not have the same size, the virtual one is bigger based on your images.

When placing virtual content in 3d the real world based on one perspective alone getting 100% alignment with the real world is tricky. Perspective projection makes it hard to tell if the object is actually aligned, unless visualized from two sides at the same time. Some of the error may come from here.

Secondly A3 does not have a specialized eye calibration (e.g.: inter pupillary distance) that adapts to each different person wearing the glasses but an approximation that works okay for most people but sacrifices accuracy. The easiest way to see this effect is the Image Tracking sample, where the tracked image and the physical image usually do not align perfectly. 

You are seeing the same effect as with the cube. While the cube looks like it's placed aligned from one perspective, it is not. If you place it based on visual appearance, its placement will always be incorrect. 

Since this lack of accuracy is caused by hardware constraints of the A3 device (you would need eye tracking to automatically adapt for each user automatically), there isn't really a fix for this. 

There are no phenomenon that the object produced in other companies

I asked the sample code but I can't get it

We want to fix it

Also, there's the same problem, there is the same problem

Are there other apps running on A3 that do not have the same behavior? I'm having trouble interpreting what your previous comment means - please clarify. 

If the problem is caused by the eye calibration, then there is no workaround available to fix this for you. Accounting for pupillary distance and allowing users to input their personal measurements may improve the offset issue. Currently the Snapdragon Spaces SDK doesn't have a way of doing that. 

I can file a feature request for this for our product team to consider if you'd like. Please note that the feature request process may take several months.

I uploaded a video

When anchoring is performed, the object is fixed in the correct position in the front

Even if you move it from side to side, the object will go wrong


What we want is like a new video uploaded

It means that the projection doesn't go wrong even if you move it left and right



in addition to the prior two explainations for the offset, seeing that you are using the Anchors sample, I can add a third reason to the list; The anchor is placed on the mesh that's generated by our Meshing and Mapping feature. Because of resource and hardware constraints this mesh is not a 1:1 representation of the real world but an approximation. Placing the anchor on the mesh may cause this offset when viewing the from another side. 

In the Quest sample, are you referring to the controllers? Comparing anchors to controllers for tracking is comparing fundamentally different tracking technologies. 

Unfortunately, there is no fix for this on A3 because these inaccuracies are mostly caused by hardware constraints. You can try to mitigate the issue by placing your objects from one side first, then allowing users to adjust the positon based on a second viewing angle. Imagine it the way a 3D artist may do in Blender - while placing an object, view it from multiple sides in order to accurately place it. 

Is it right that anchoring does not work precisely in A3 when it comes to hardware constraints?

I heard that some error can occur, is it normal for the offset to be around 30cm?

To be precise; rendering objects at an exact location doesn't work precisely on A3, anchoring does work. 

The estimated 30 centimeter offset you are seeing on the first anchor in the video seem normal to me. The offset is caused by inaccurate placement rather than tracking of the Anchors not working. This is because the anchor is placed on the mesh surface which is rather inaccurate for smaller objects like the one in your video. 

Our sample implements Anchors using the mesh, but you do not need to place the anchor on the mesh surface. If you know the location of your object, you can place the anchor anywhere and it will be tracked. 

After placing an anchor a small drift can ocurr, based on environmental conditions such as few features in the environment or brightness. Based on your video this drift is very minimal for you. 

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