Baking Static Lightmaps in Games: Full Guide

Baking lightmaps is the only way to get physically correct HDR lighting without FPS drops on mobile platforms and in VR. But the process is not just clicking the Bake button: it requires control of UV unwrapping, configuration of Progressive Lightmapper, and quality denoising via Optix or OpenImageDenoise. Mistakes at any stage lead to artifacts — dark bands on seams, blurry shadows, memory overhead of 30–50%.

We have been baking lightmaps for projects for over 5 years. During this time, we have worked on dozens of commercial games: from mobile strategies to PC action titles. Our approach is detailed geometry audit, manual UV1 correction in Blender, and compression selection for the target platform (ASTC for iOS, ETC2 for Android). We guarantee quality — lightmaps that are presentable in the final build.

In this article, we will break down the technical details: why UV1 is the main source of problems, how to properly configure Progressive Lightmapper (direct samples, indirect samples, maximum bounces), and which compression formats to choose for different platforms. We will also share a real case from practice — a mobile strategy with a 4 MB limit per scene.

Why UV1 Unwrapping Is the Main Cause of Problems

Progressive Lightmapper bakes lighting into UV Channel 1. If this channel is set incorrectly, no parameters will save you. Three hard requirements: islands must not overlap, padding from the atlas edge must be at least 2 pixels, and island size must be proportional.

Automatic UV generation (Model → Generate Lightmap UVs) often creates islands that are too small on architectural objects — dark bands appear on seams due to padding artifacts. For such objects, we manually create UV1 in Blender or Maya. We verify using the Lightmap UV Preview in the Scene View. Experience shows that manual unwrapping reduces defect rate from 40% to 5%.

How to Configure Progressive Lightmapper for Quality Results

Key parameters: Lightmap Resolution — 10–20 for near objects, 2–5 for distant ones (via Lightmap Parameters Assets). Direct Samples 64, Indirect Samples 512 — baseline for production. Max Bounces — 2 for most scenes, 4 for glass interiors. Denoising — enable Optix (NVIDIA) or OpenImageDenoise (Intel). The GPU version of Progressive Lightmapper speeds up baking by 5–15 times compared to the CPU version.

Case: Lightmaps for a Mobile Strategy — From Our Practice

Our client was a mobile strategy game with an isometric view, 20+ scenes. Requirement: lightmaps ≤ 4 MB per scene. With standard settings — 6–8 MB. Solution: one atlas of 2048×2048 instead of several 1024×1024 (better bin-packing), disabling Contribute GI for invisible surfaces. Result — 2 MB in ETC2 while preserving foreground quality. Memory savings — 40%.

Comparison of Lightmap Compression Formats

What Is Included in Lightmap Baking Work

• Audit of current UV unwrappings and correction of problematic objects.
• Configuration of Lightmap Parameters Assets per object class.
• Test baking (Direct 8, Indirect 32) to verify structure.
• Final baking with production parameters and denoising.
• Compression optimization for the target platform.
• Verification in the build and adjustments.

Stages of Lightmap Baking Work

1. Geometry and UV channel audit.
2. Configuration of baking parameters and Lightmap Parameters Assets.
3. Test baking with low quality.
4. Final baking with denoising.
5. Compression and testing on the target platform.

For an accurate project estimate, contact us — we will analyze the current state and propose the optimal solution. Order a lighting audit to avoid common mistakes. We work with studios from the CIS and Europe and have completed more than 30 baking projects.

Details in the official Unity documentation: Progressive Lightmapper.

What problems does lighting setup solve?

A studio spends four hours per bake per scene. A UV seam artifact appears, the artist fixes it, and waits another four hours. This repeats three to five times daily across multiple scenes, wasting weeks. An incorrect lighting strategy from the start — all sources in Realtime — can cost 30–50% FPS on mobile or consoles at release. Our Expert Lighting and Rendering Setup Services address two core pain points: baking time and runtime performance. We audit the existing system, choose the right mix of dynamic lighting and baked methods, and deliver measurable gains. Over 30 projects delivered, from indie to AA. Certified Unity specialists guarantee the result.

Dynamic, static, and mixed lighting: how to choose?

Each light source in Unity has three modes. The table shows how they affect performance:

A common mistake: a studio sets all lights to Realtime, resulting in 12 shadow-casting lights on screen. On mobile, that’s a guaranteed 30% FPS drop. Mixed Lighting with Subtractive or Shadowmask sub-modes is the practical compromise. Static objects get baked shadows, dynamic objects get realtime shadows from same sources — a balanced dynamic lighting mix.

Typical artifacts and their causes

How to optimize baked lighting without losing quality?

Choosing between Enlighten and Progressive Lightmapper

Unity supports two baking backends. Enlighten is legacy real‑time GI — officially outdated but still used on mobile due to low system requirements. Progressive Lightmapper (GPU) is a modern path‑tracing backend. On an NVIDIA RTX card, GPU baking is 5–10x faster than CPU. We default to Progressive Lightmapper (GPU) for PC and consoles.

Key parameters for a typical scene:

Lightmap Resolution:    10–20 texels/unit
Max Bounces:            2–4 (not default 8)
Samples (Direct):       32–64
Samples (Indirect):     512–1024
Denoiser:               OIDN or OptiX

Denoiser is mandatory. Without it, you need thousands of samples for clean results. With denoiser, 256–512 samples suffice. Iteration takes minutes, not hours. According to Unity documentation, this setup reduces baking time by 50–70% without quality loss.

Light Probes and Reflection Probes: why and how to set up?

Light Probes give dynamic objects the illusion of baked lighting. Place probes every 2–4 meters in areas with lighting variation. Too sparse placement causes sharp jumps when characters move. Probe Volumes (HDRP) replace manual placement with a volumetric grid — saves time on large open scenes.

Reflection Probes correct reflections on PBR materials. Without them, metal and mirrors reflect the skybox instead of the environment. Settings:

• Baked for static rooms
• Realtime for zones with changing environment (TV, screens)
• Box Projection for correct room geometry reflection

Applying these rules reduces draw calls for reflections by up to 40%.

What is the impact of scene organization on baking speed?

Scene scale is the main enemy of fast baking. Here’s the process we use:

1. Exclude objects smaller than 0.5 units — they receive lighting via Light Probes.
2. Use Instanced Meshes for repetitive objects (trees, rocks, fences) — one UV atlas shared.
3. Bake Terrain separately at reduced resolution (2–5 texels/unit).
4. Check Backface Tolerance on complex geometry — prevents dark spots.

Following these steps cuts total bake time by 50–70%. In one open‑world Unity project, original bake time was 4 hours per scene. After optimization: 1 hour 20 minutes. Monthly time savings exceeded 40 hours, equivalent to $3,000 monthly cost reduction.

What’s included in lighting setup work

Our turnkey service delivers:

1. Audit of current system — profiling via Frame Debugger and RenderDoc, identifying bottlenecks.
2. Lighting strategy — documentation with mode selection (Mixed/Baked/Realtime) for your platform.
3. Baking optimization — UV unwrapping, Progressive Lightmapper configuration, Light Probes.
4. Reflection Probes setup and post‑processing (SSAO, SSR, Bloom) matching your artistic style.
5. Final report with performance metrics (FPS budget, draw calls, frame times).
6. Post‑delivery support for two weeks — remote session to review any issues and transfer knowledge.

Work process and timeline

We follow a clear workflow:

• Analysis (1–2 days) — review scene, take screenshots, profile.
• Design (1 day) — select strategy, create optimization plan.
• Implementation (3–7 days depending on complexity) — UV fixes, Lightmapper settings, Light Probes, post‑processing.
• Testing (1–2 days) — measure performance, remove artifacts.
• Delivery — scene files, documentation, checklist.

Typical timeframe: 5 to 15 business days. Pricing is individual — contact us for a project estimate.

Get a free audit of your current lighting setup. Reach out to discuss your project — we will provide a concrete plan and timeline.