Many AR applications allow user to select a 3D object and display in the phone. If the user walks into a different area. The 3D object still remains at the same location. How can i achieve this? Can GPS solve this problem? But GPS is not accurate in indoor.
You can do it by using ARKit, ARCore or Vuforia SDKs. In ARKit and ARCore you can anchor objects to physical locations and they will stay there even if you walk into a different room. However, you might notice some drift in the location in ARCore because environmental understanding of device change over time or you might lose tracking at some point. With Vuforia you can use extended tracking to track objects but it is a bit different than ARCore and ARKit. You have to use ground plane or smart terrain to utilize extended tracking fully in your situation.