Verifying Correct Scale of VR Graphics Objects

In regular games, scale is a convention. A sword can be longer or shorter — no one notices. In VR, the user stands next to objects. A table 90 cm high is perceived by the brain as "correct" or "too low" — because the person has interacted with real tables. A door frame of 1.9 m makes you instinctively duck. An object the size of a fist that looks head-sized in VR destroys perception.

We help VR project developers eliminate scale distortions that break immersion. A typical scenario: loading a scene from Blender, putting on the headset — and feeling "something is off." The floor is at the wrong height, the door frame seems narrow, even though metrics in the editor are correct. Our verification is not a subjective assessment but a systematic test of each asset for physical size compliance. The team has over 10 years in VR development and dozens of projects for major clients.

Proper scale calibration saves up to 30% of the revision budget — timely detection of Scale Factor errors eliminates rework before the build stage. Contact us for a consultation and assessment of your project.

How Unity Determines Scale for VR

Unity's basic rule for VR: 1 unit = 1 meter. This is not a recommendation — it's a requirement. If a scene was modeled in other units (centimeters, inches) and imported without conversion, all objects will be either gigantic or microscopic in VR.

A frequent source of problems is import from 3D editors. Blender works in meters by default, Autodesk Maya in centimeters. An FBX file from Maya without explicit unit specification ends up in Unity with a Scale Factor of 0.01 on ModelImporter. The object appears "correct" only if somewhere along the transform chain this factor is compensated. If not — it's either 100 times smaller than needed, or the developer manually sets Scale (100, 100, 100) on the GameObject, breaking physics calculations and NavMesh.

The correct approach when importing: in ModelImporter → Model → Scale Factor, set the value that brings the object to real meter dimensions. For Maya FBX this is usually 0.01. After that, verify: a human character should be 1.7–1.85 m from feet to top of head.

Why Reference Objects Are Critical for VR

For scale verification in VR, we use reference objects — meshes with known real-world sizes:

• Average adult height: 1.75 m (floor to top of head)
• Standard door frame: 2.0 m height, 0.9 m width
• Dining table: 0.75 m height
• Chair: 0.45 m seat height from floor
• Car (passenger): ~1.5 m height, 4.5 m length
• Brick: 25 × 12 × 6.5 cm

We create a ScaleVerificationScene with these reference objects and a floor plane. Each new or modified asset is placed next to the references in VR and visually verified. This takes 2–3 minutes per asset and eliminates the class of problems "looked fine in the editor, looks weird in VR."

VR Height Reference — a special tool in XR Interaction Toolkit Samples: a virtual mannequin with standard proportions placed in the scene for quick visual scale checking of interactive objects.

Hand Scale and Reachable Zone

In VR, the player's hands are part of the game geometry. If virtual hands are visually "short" compared to handles and buttons in the scene — the player reaches for an object but cannot touch it. Discomfort without an obvious cause.

Reachable zone: an average adult's arm extends 0.7–0.8 m from the shoulder. In VR, XRRig.cameraFloorOffsetObject determines the camera height above the floor. Interactive objects should be placed in the comfortable reach zone: 0.5–1.2 m height, no further than 0.6 m horizontally from the body center.

Test: every interactive object in the scene undergoes a reachability check. Method: in the editor, use Gizmos to draw a sphere of radius 0.7 m from XRRig.centerEyeAnchor — all interactive objects must at least partially intersect this sphere.

How to Automate Scale Checking

For projects with a large number of assets, manual verification is inefficient. We create an editor tool — an EditorWindow in Unity that:

1. Collects all GameObjects with the tag Interactable or the XRBaseInteractable component.
2. Checks their Bounds.size against predefined min/max for the object category (weapon: 0.15–1.5 m, furniture: 0.3–2.5 m).
3. Outputs a list of objects that fall outside the normal range.

Thresholds are set in a ScriptableObject ScaleVerificationConfig. This does not replace visual VR checks but filters out obvious errors — accidental scale 0.01 or 100 on imported objects.

Additional check: ModelImporter for all FBX in the project — ensure no objects have scaleFactor != 1 after normalization. This is handled by an import post-processor (AssetPostprocessor.OnPreprocessModel) that logs or automatically corrects incorrect scale factor.

Automated scale checking is 10 times faster than manual: 0.2–0.5 minutes per asset instead of 2–5, while catching up to 90% of gross anomalies.

What the Work Includes

• Report with audit results of current asset state (Scale Factor, Bounds, reachable zones).
• Correction of Scale Factor for all imported models.
• Setup of reference scene ScaleVerificationScene with reference objects.
• Development of an editor tool for automatic scale checking.
• Consultation on further integration and support.

using UnityEditor;
using UnityEngine;

public class ScaleFactorNormalizer : AssetPostprocessor
{
    private void OnPreprocessModel()
    {
        ModelImporter importer = (ModelImporter)assetImporter;
        if (importer.scaleFactor != 1f)
        {
            Debug.LogWarning($"FBX {assetPath} has scale factor {importer.scaleFactor}. Consider normalizing.");
        }
    }
}

Verification Process

Estimated timelines: basic audit — 2–5 days, full verification of all assets for a large project — 2–4 weeks. Cost is calculated after evaluating the number of assets and scene complexity. Get a consultation for an accurate estimate.

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.