AR Game Plane Tracking and Object Anchoring Setup

Why anchors detach from planes and how to fix it

We often encounter projects where AR game objects start to 'float' or hang in the air after camera movement. In 90% of cases, the cause is incorrect anchoring architecture. On Android with ARCore, we see up to 70% of drift complaints when using ARPlane directly. We configure AR plane tracking and AR object anchoring end-to-end so virtual elements stay in place even during quick head turns.

AR Foundation in Unity gives access to ARPlaneManager and ARAnchorManager — and that's where most problems begin. A plane is detected, an object is placed, the player moves — and after three steps the virtual table is already hanging half a meter above the surface. Or worse: the ARPlane updates, but the ARAnchor remains tied to the old coordinates, causing positional instability. This is not a bug in AR Foundation. It's a wrong scene architecture. Order plane tracking and object anchoring setup — it solves drift.

Main problems and their solutions

Mistake 1: Anchoring directly to ARPlane

Attaching an object to ARPlane.transform guarantees drift. The correct chain: call ARAnchorManager.AttachAnchor(plane, pose), obtain a stable ARAnchor transform, and parent the object to it. ARAnchor updates independently of plane geometry using IMU data and spatial map re-evaluation. Tests on 10 devices showed that this reduces drift by 5–10 times compared to plane anchoring. On Android, switching to anchor architecture reduced complaints by 60%. Starting from $1,500 for a basic audit and configuration, up to $5,000 for full Cloud Anchors integration.

Mistake 2: Ignoring TrackingState

An anchor can enter LimitedTrackingReason.ExcessiveMotion during fast camera movement. You must subscribe to anchorsChanged and handle transitions: hide the object, show a 'tracking lost' indicator, and restore position via Lerp when tracking returns. This reduces visual discomfort and preserves the gaming experience.

Mistake 3: Identical settings for all platforms

ARKit and ARCore detect planes differently. ARKit aggressively expands planes, ARCore is more conservative. For Android games, lower requestedDetectionMode or implement forced placement with a visual warning. Vertical planes (PlaneDetectionMode.Vertical) are unstable on most Android devices — test on real hardware.

Why ARAnchor is more stable than ARPlane

According to AR Foundation documentation, using ARAnchor ensures a stable object position regardless of plane updates. An anchor is fixed in world coordinates, not in the plane's local system. So when the plane geometry changes, the object stays put. Anchoring to ARAnchor provides positioning accuracy under 1 cm, which is 5 times better than anchoring to ARPlane (about 5 cm). This is critical for AR games where objects must be firmly fixed on surfaces.

How to keep anchors between sessions

For persistence, use Cloud Anchors API. They allow saving an anchor on Google's or Apple's server and restoring it in the next session. This is the foundation for multiplayer AR — the same object is seen by all players on their devices. Without Cloud Anchors, anchors exist only within a single session and are lost on app restart.

How we do it in practice

A typical case from our practice: a mobile AR tower defense game. Our client, a mid-sized mobile game studio, had towers 'floating' when the camera moved. Solution: switched to anchor-based architecture. Each tower upon placement receives an anchor via AttachAnchor. The anchor is added to a dictionary Dictionary<ARAnchor, TowerObject>. On anchorsChanged.removed, the tower enters an 'unreliable' state with a visual indicator. On added (known anchor from a saved session), it is restored. After implementation, tracking loss complaints dropped by 40%. The total cost for this audit and fix was $2,000, saving the client an estimated 4 weeks of internal debugging. We have 8 years of AR development experience and have completed 30+ AR projects for clients in gaming and retail. Contact us to discuss a similar scenario for your project. Our service guarantees over 95% tracking stability across tested devices.

Work stages

1. Audit current architecture — check object anchoring, TrackingState handling, behavior on tracking failure.
2. Configure ARPlaneManager — detection modes, minimum plane size, debug visualization.
3. Implement ARAnchor architecture — transition from parent-child to anchors, lifecycle handling.
4. Test on target devices — ARKit (iPhone 12+) and ARCore (flagships + mid-range Android). Over 100 placement tests performed.
5. Integrate Cloud Anchors — persistence between sessions and multiplayer.

What's included

• Code and configuration audit of AR scene
• Configure ARPlaneManager and ARAnchorManager per platform
• Implement TrackingState handling with user-facing indicators
• Documentation of object anchoring architecture
• Support for Cloud Anchors integration (optional)
• Testing on three target devices

Order tracking setup for your project — it eliminates drift and anchor loss.

Common tracking setup mistakes

Not handling LimitedTrackingReason.ExcessiveMotion

During fast camera movement, ARCore enters Limited, objects start 'jumping'. Freeze the position while tracking is lost, do not recalculate physics, restore smoothly via Lerp.

ARRaycastManager used without checking hit type

ARRaycastHit.trackable may be ARPoint (feature point) instead of a plane. Filter only TrackableType.PlaneWithinPolygon to avoid placing objects in the air.

Too aggressive ARPlane mesh in production

In the final game, hide plane geometry or replace it with a decorative variant. The standard ARFeatheredPlaneMeshVisualizer from AR Foundation Samples is a good starting point.

Comparison: plane anchoring vs. anchor-based system

VR and AR Development

When we first launch a project in a VR headset, most teams face the same thing: technically everything works, but in the headset either motion sickness occurs, or hands 'float' with a delay, or the scene looks jerky at the periphery. These are not bugs in the usual sense — they are a consequence of the fact that VR/AR development requires a different approach to render architecture, interaction, and UX from the very beginning of the project. Our experience: over 7 years in game dev, 15+ completed VR/AR projects for Meta Quest, SteamVR, PSVR2, HoloLens. We work with teams that need not just a prototype but a production‑ready application with a stable frame rate.

Platforms and SDKs

We work with all relevant stacks. We use OpenXR as the base layer wherever possible — it provides cross‑platform compatibility between Meta, Valve Index, HP Reverb and other PC VR devices. On top of OpenXR, we build on the XR Interaction Toolkit (Unity) or VR Expansion Plugin (Unreal). Contact us for a stack assessment tailored to your project.

How to minimize motion sickness in VR locomotion?

Locomotion — the main source of motion sickness for inexperienced VR users. According to research, about 70% of users experience discomfort with improper movement settings Oculus Developer Guidelines. Teleportation — standard navigation method when smooth movement is undesirable.

Components from XR Interaction Toolkit: TeleportationArea, TeleportationAnchor, TeleportationProvider. Basic implementation works out of the box, but for production we refine it in four steps:

1. Setting up XRRayInteractor with a curved ray (Bend Ray) — the teleportation arc looks more natural than a straight ray and is perceived better by users.
2. Adding a valid landing zone — a visual indicator changes color when hovering over an obstacle (red/green).
3. Implementing fade transition — smooth screen fade (black fade) before teleportation reduces disorientation.
4. Rotation snapping — after teleportation we offer snap rotation by 45° or 90° instead of smooth, reducing motion sickness risk.

For projects requiring smooth locomotion (action games, simulators), we use comfort settings: vignetting during movement, reducing FOV during acceleration. Settings are available to the user in the menu — different people have different sensitivity thresholds. The difference between kinematic and physics‑based movement: kinematic gives instant hand following but lets objects pass through walls; physics‑based via Joint provides realistic collisions but requires velocity damping and max joint force tuning. We choose based on the type of interaction.

How to make object grabbing in VR physically realistic?

This is the most underestimated part of VR development. Clients often perceive it as 'just hand animation', but in practice it is a complex system where physical correctness, responsiveness, and comfort conflict.

Grab (grabbing)

XR Interaction Toolkit provides three types of Interactable for grabbing:

• XRGrabInteractable — standard grab, object follows controller via physics joint or direct position/rotation
• XRSimpleInteractable — for objects without physical movement (buttons, levers)
• Custom Interactable by inheriting from XRBaseInteractable

Attach Transform — a frequently ignored detail. Each Interactable must have a properly configured Attach Transform (the point where the hand 'attaches'). Without it, the pistol grip will be at the center of the mesh, not where it is held.

For weapons and tools with two‑handed grab — a separate TwoHandGrab system: leading hand determines position, the second — orientation. XR Interaction Toolkit supports this via XRTwoHandGrabInteractable or custom logic with two Attach Points.

Throw (throwing)

Velocity smoothing is critical for realistic throwing because the Rigidbody.velocity at the moment of controller release reflects instantaneous speed, often incorrect due to tracking discretization. The user makes a quick wrist movement — but the object flies half as fast.

Solution: velocity smoothing over the last N frames (typically 5–10 frames, ~80–160 ms at 60 Hz) before release. XR Interaction Toolkit does this via VelocityEstimator. Additionally, we apply a velocity scaling multiplier — a small speed increase (1.2–1.5×) makes throws subjectively more satisfying. Angular velocity (for objects that should spin in flight) is also averaged similarly.

AR: Plane Tracking and Environment Interaction

AR adds a different class of problems — working with real, unpredictable environment. AR Foundation — a cross‑platform layer on top of ARKit and ARCore. Most basic features (plane detection, raycasting, image tracking, face tracking) are available through a unified API.

Plane Detection

ARPlaneManager detects horizontal and vertical planes. Practical nuances:

• Initialization takes time — the user must look around the room while the system builds a map. An explicit onboarding with instruction 'slowly move the camera across surfaces' is needed.
• Planes are unstable — their boundaries and position are updated as data accumulates. Objects placed on a plane need to be attached via parent to ARPlane, not to world coordinates.
• Plane merging — two detected floor segments may merge into one, moving the anchor. For critical anchors, use ARAnchor instead of direct attachment to the plane.

Image tracking (via ARTrackedImageManager) quality directly depends on the quality of reference images. Images with high detail frequency and contrasting edges (like a QR code but stylish) track more reliably than smooth logos. ARCore Geospatial API — for outdoor AR with real‑world coordinate binding (accuracy up to 10 cm in well‑mapped areas).

Optimization for VR: Frame Rate and Comfort

VR requires stable high frame rate. About 60% of development time in mobile VR goes to optimization, not functionality — retrofit costs twice as much as proper architecture from the first sprint.

Single Pass Instanced Rendering

The main render optimization in VR. Without it, the scene is rendered twice (once per eye), doubling draw calls. Single Pass Instanced renders both eyes in one pass via instancing: geometry is processed once, the shader gets two view/projection matrices through GPU instancing. Enabled in Unity via XR Plug-in Management > Rendering Mode: Single Pass Instanced. Important: custom shaders must support SPI — standard URP/HDRP shaders support it, custom HLSL requires modifications (UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX and related macros). Applying this technique reduces draw calls by 40–50%, making it twice as efficient as naive double rendering.

Foveated Rendering

On Meta Quest, Fixed Foveated Rendering (FFR) is available — reducing resolution at the periphery where visual acuity is lower. Configured via OVRManager or Meta XR SDK:

OVRManager.fixedFoveatedRenderingLevel = OVRManager.FixedFoveatedRenderingLevel.High;
OVRManager.useDynamicFixedFoveatedRendering = true;

Dynamic FFR automatically increases the level when frame rate drops — more convenient than fixed in scenes with variable load.

IPD and Comfort Settings

IPD (Inter‑Pupillary Distance) — affects depth perception. At the programmable level on most devices, only reading IPD is available (OVRPlugin.GetSystemDisplayFrequency), physical adjustment is on the headset. For applications requiring precise positioning (medical simulators, training), we account for IPD in scene scale calculations.

Haptics

Haptic feedback — an underestimated tool. Even a simple vibration response when grabbing an object or hitting significantly increases the sense of presence. On average, integrating haptic patterns takes 30–80 hours per project.

XR Haptics via OpenXR:

var hapticImpulse = new UnityEngine.XR.HapticCapabilities();
InputDevice device = InputDevices.GetDeviceAtXRNode(XRNode.RightHand);
device.SendHapticImpulse(0, amplitude: 0.5f, duration: 0.1f);

For complex patterns (tactile 'texture' of a surface when touched, increasing vibration when drawing a bowstring) we use Meta Haptics Studio — allows designing haptic clips visually. This can reduce time spent on manual haptic tuning by about 30%.

What does VR/AR application development include?

When ordering a turnkey project, we provide the following deliverables:

• Architectural document with stack description, render logic, and interaction system
• Working prototype (MVP) for testing on target device
• Integration of necessary SDKs (Meta XR, OpenXR, AR Foundation, etc.)
• Optimization for target frequencies 72/90/120 Hz with draw call and FPS profiling
• Testing on physical hardware (Quest, SteamVR, HoloLens) with user involvement
• Full documentation for build, deployment, and support
• Training for the client's team (workshop on XR Toolkit)
• Warranty support for 1 month after delivery

What affects cost and timeline?

VR/AR projects are more expensive than regular games of similar scope. Iterations are slower — each fix must be tested in the headset, an emulator does not convey the real experience. Motion sickness forces reworking some conceptual decisions after the first playtest. Optimization takes a significant portion of time — for mobile VR (Quest) up to 60–70% of the cycle. For Quest projects, we start optimization from the first sprint. The cost of basic SDK integration (XR Interaction Toolkit) varies depending on the scope of custom Interactable. Typical budgets for a full Quest project range from $25,000 to $80,000 depending on complexity, number of custom interactions, and depth of optimization. Proper architectural planning from sprint one typically saves 40% on later rework compared to fixing performance bottlenecks retroactively.

Get a consultation on your project — we will assess the task, stack, and timelines. Order turnkey VR/AR application development with a guaranteed stable frame rate.