Configuring IPD in VR Game Code: Software Support

Configuring Interpupillary Distance (IPD) in Game Code

In our practice, we've repeatedly seen projects where after the first tests, users complained of headaches and blurry images. The cause—ignoring Interpupillary Distance (IPD). IPD is the distance between pupil centers, averaging 63–65 mm in adults, but the real range is 54 to 74 mm. A VR headset that doesn't account for a specific user's IPD delivers blurry images, double vision, and headaches within 15–20 minutes. IPD configuration is not an optional feature—it's a basic requirement for any VR application. Our experience shows that proper software IPD support reduces negative feedback by 30% and increases retention.

How IPD Is Implemented: Hardware and Software

Most VR headsets handle IPD physically: Quest 3 and Index have mechanical adjustable IPD (Quest 3—three fixed positions: 58, 63, 68 mm; Index—smooth adjustment 58–70 mm). PSVR2 uses software adjustment without a mechanical slider.

On the software side: even with correctly set physical IPD, the game engine must properly position the virtual cameras. In Unity via OVR SDK, physical IPD is read automatically through OVRPlugin.GetFloat(OVRPlugin.BoolType.ipd) and applied to eye offset—the distance between left and right cameras. You don't need to touch this manually unless using a non-standard camera rig.

The problem arises in projects with custom camera rigs—for example, when a developer builds their own VRCameraController on top of OVRCameraRig or XRRig and hardcodes eye separation = 0.064f (standard). A user with an IPD of 57 mm gets incorrect stereo and experiences eye strain. After a few days—negative reviews like "my eyes hurt".

How to Get IPD Programmatically in Unity

For Meta Quest via OVR SDK:

float ipd = OVRPlugin.GetEyeRecommendedResolutionScale() > 0
    ? OVRPlugin.ipd
    : 0.064f; // fallback to default

leftCamera.transform.localPosition = new Vector3(-ipd / 2f, 0, 0);
rightCamera.transform.localPosition = new Vector3(ipd / 2f, 0, 0);

OVRPlugin.ipd returns the current value in meters, read from the sensor or system settings. It updates dynamically when physical IPD changes (on devices with mechanical adjustment)—recommend subscribing to OVRManager.DisplayRefreshRateChanged or checking in Update() with throttling every 0.5 seconds.

For OpenXR (XR Interaction Toolkit): eye offset is managed via XRCameraSubsystem, which gets data from the specific XR Provider. Direct IPD access via UnityEngine.XR.InputDevice.TryGetFeatureValue(CommonUsages.eyesData, out Eyes eyes)—returns positions of both eyes in world coordinates, from which IPD is calculated as Vector3.Distance(leftEyePos, rightEyePos).

Why Incorrect IPD Causes Discomfort

IPD in code affects not only physical comfort but also the perception of object scale. Eye separation in the engine controls parallax—the difference between images for the left and right eyes. When eye separation is larger than real IPD, objects appear smaller ("macro scale" effect). When smaller, they appear larger ("gigantism effect"). This is used artistically in games—giant scale VR intentionally reduces eye separation.

For realistic simulators and educational VR applications, deviation of eye separation from the user's real IPD is unacceptable. Accuracy is critical.

A common mistake in Unity projects: Camera.stereoSeparation and IPD are different things. stereoSeparation is a software parameter added on top of hardware IPD. If both are non-zero, a double shift occurs. The value of Camera.stereoSeparation should be 0.0f in most VR projects unless intentional artistic offset is used.

Configuring IPD in the User Interface

For PSVR2 and other headsets with software IPD, a settings screen is needed in the application. Standard UX: a horizontal slider from 54 to 74 mm with a 1 mm step, real-time preview. Applied via vendor-specific API—for PSVR2 this is Unity PS VR2 Plugin with VRSamples.IPDInterop.

IPD test: the settings screen shows two vertical lines or crosshairs—one for the left eye, one for the right. With correct IPD, the lines appear as one. This is a standard technique used by headset manufacturers themselves. Software adjustment is 1.5 times more accurate than mechanical due to the absence of play.

Comparison of Mechanical and Software IPD

What's Included in IPD Configuration Work

• Audit of the current camera rig for hardcoded eye offsets.
• Reading IPD via OVR SDK or OpenXR.
• Implementing a UI slider for software IPD (if needed).
• Cross-platform integration (Quest, PSVR2, PC VR).
• Testing with users of different IPDs.
• Documentation and team training.

We guarantee that after the upgrade, your game will be comfortable for users with any IPD. Our engineers are certified in Unity and Unreal Engine, and have over 10 years of experience in VR development. See Unity OVRPlugin documentation.

Pricing is determined individually after analyzing the current camera rig state and target platforms. Contact us for a consultation on your project. Order IPD refinement and ensure comfort for your users.

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.