Baked Lighting and AO for VR: Setup and Optimization

Realtime global illumination in mobile VR is a dream that shatters against 6.9 ms per frame. On Quest 3, neither Lumen nor decent-quality SSAO is possible without drops. We offer the only way to get rich lighting with complex shadows and contact AO — bake it in advance. Our team has 10+ years of VR development experience and has completed over 50 projects for Quest and PC VR.

But baked lighting in VR comes with its own set of problems not present on flat screens. Let's break down each one.

How to avoid UV seams in VR?

The first headache is seam stitching. With default settings, the edges of adjacent UV islands on the lightmap produce dark or bright lines at mesh seams. In a regular game, this is masked by a moving camera. In VR, a stationary player examines a room corner up close and sees every artifact.

Solution: in Unity, enable Stitch Seams in Lightmap Parameters settings, reduce texel size to 0.1–0.2 for static environment meshes, and ensure UV2 (Lightmap UV) has sufficient padding — at least 2 pixels for a 512 atlas, 4+ pixels for 1024 and above.

Why does temporal flickering occur specifically in VR?

If the lightmap contains gradients with high-frequency details (sharp shadows from small objects), Asynchronous TimeWarp picks up the old frame and interpolates — a slight shimmer appears on static surfaces. This is solved by smoothing the AO radius and disabling sharp point shadows during baking.

Stereo mismatch is another feature. In VR, two eyes see the scene from slightly different angles. Baked specular highlights are baked for a single viewpoint and do not change with head movement, breaking depth perception. For mobile VR, it's better not to bake specular at all — only diffuse + AO.

How to properly set up baking for a VR scene?

Choosing a baking backend. In Unity, Progressive Lightmapper is standard. GPU Progressive (via OIDN denoiser) is faster but requires tuning: increase Sample Count to 512–1024 for gutter zones, enable Prioritize View for areas visible from typical player positions.

Splitting into Baked and Realtime. Not every environment needs to be baked. Static walls, floors, ceilings, large furniture — into Baked. Objects that may move or react to the player — into Mixed or fully Dynamic with Light Probes. Light Probe Groups are placed where dynamic objects appear: interaction zones, NPC paths.

Ambient Occlusion. In the baked version, AO is part of Indirect Lighting or a separate map from Substance Painter/Marmoset. For VR, we recommend contact AO with a small radius (0.05–0.15 m) and high intensity: it gives objects a sense of weight without distance artifacts. A large AO radius in a VR room creates an illusion of "dirt" on walls. More about Ambient occlusion can be found in the encyclopedia.

For Quest: lightmap atlas maximum 1024×1024, ideally 512×512 for most scenes. Multiple atlases are better than one giant — this simplifies streaming when transitioning between zones. Storage format: ASTC 6×6 via override in Texture Importer.

What is included in the work?

Baking setup is performed turnkey and includes:

• Audit of the current scene: check UV, lightmap atlas, batching.
• Choice of backend and baking parameters (Sample Count, denoiser, padding).
• Placement of Light Probe Groups for dynamic objects.
• Creation of baked maps (diffuse, AO) and compression for the target platform.
• Performance test: check FPS budget (<8 ms per frame for Quest).
• Handover of the project with comments and recommendations for further support.

Our clients save an average of 30% of time on manual lighting optimization, directly reducing project budget.

Baking in third-party tools

For high-quality PC VR content, we use Marmoset Toolbag (fast GPU baker, excellent AO with ray-traced shadows) or Substance 3D Painter (for per-object baking in the texturing pipeline). The resulting maps are imported into Unity as Emissive or mixed in a custom shader with a realtime component.

For large scenes — Blender Cycles with denoise (Intel OIDN or OptiX) as an offline baker: slower, but gives cinematic-quality results for cinematic VR experiences.

| Tool | Speed | Quality | Best Use Case |

|---|---|---|---|

| Unity Progressive | Fast | Good | Medium scenes, mobile VR |

| Marmoset Toolbag | Very fast | Excellent | PC VR, high-poly |

| Blender Cycles | Slow | Cinematic | Cinematic VR, pre-render |

Step-by-step lightmap setup for VR

1. Check the UV2 of models: padding at least 4 pixels for a 1024 atlas.
2. Disable specular in baking for mobile platforms.
3. Use OIDN denoiser for GPU Progressive.
4. After baking, check the scene in VR mode via Oculus Link or SteamVR.
5. If necessary, reduce texel size for critical areas.

Estimated timelines

| Scene | Timeline |

|---|---|

| Small interior room | 1–2 working days |

| Medium scene (5–10 zones) | 3–5 working days |

| Large open location | 1–2 weeks |

The cost is calculated individually after an audit of the scene and quality requirements. Contact us for a free audit of your VR scene — we will analyze the current settings and propose optimal baking parameters.

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.