In an Augmented Reality scene, users looks at the live camera feed. Virtual objects anchor at specific positions of the real world. Our task is to let the user place virtual in the real world. To achieve that, the user simply taps on the smartphone screen. Through a hit test, our script then creates an anchor in the real world and links that to a virtual 3D model entity.
That’s the high level overview. To code this anchoring logic, a few intermediate steps are needed:
- Hit Test: converts coordinates of the user’s screen tap and sends the normalized coordinates to the AR system. This checks what’s in the real world at that position.
- Register Anchor: next, our script instructs the AR system to create an anchor at that position.
- Link Anchor: finally, the ID of the created anchor is linked to our entity. This allows Sumerian to continually update the transform of our 3D entity. Thus, the object stays in place in the real world, even when the user moves around.
Transforming these steps into code, this is what our code architecture looks like. It includes three call-backs, starting with the touch event and ending with the registered and linked AR anchor.