We have an house exported from blender and added some 2d gui buttons to the scene to interact with the object and link the user to a subsite.
The problem is when you rotate the object via arc camera the opacity of the buttons change when they are close or partialy behind the object (see video Imgur: The magic of the Internet). I tried to reproduce it here but it is not the same behavior as in my example. https://playground.babylonjs.com/#MHKKUX#2
Following is how i add the button to the scene:
const plane = BABYLON.MeshBuilder.CreatePlane('btn-label-' + alias, { size: 5 }, scene);
const advancedTexture = GUI.AdvancedDynamicTexture.CreateForMesh(plane);
const button = GUI.Button.CreateImageOnlyButton('but', '/house3d/textures/target.png');
plane.position = new BABYLON.Vector3(posX, posY, posZ);
plane.billboardMode = BABYLON.TransformNode.BILLBOARDMODE_ALL;
button.width = 1;
button.height = 1;
button.thickness = 0;
advancedTexture.addControl(button);