# Lighting and Baking > [!important] Version requirement > **General (desktop / editor workflows):** Unity **6000.5+** with the **Universal Render Pipeline (URP)**. > **Meta Quest / mobile sections:** target **Unity 6.3 LTS (6000.3.27f2 or newer)** — the same baseline as [[Meta Quest 2]] and [[0.Choosing a Unity Version]]. Do not treat 6000.4 / 6000.5 as Quest-safe; those lines are EOL for the Quest tutorial track. > [!warning] Verification status > Light modes, Progressive GPU Lightmapper settings, lightmap UV generation, Adaptive Probe Volumes (APV) enable/bake flow, and Reflection Probe Inspector properties were checked against Unity Manual pages for the **6000.0 / 6000.x** documentation set (URLs cited in each part). C# helpers were **not compiled in Unity**. Inspector labels and menu paths can drift between minor versions — confirm against your installed Editor. Items marked *(unverified)* are flagged inline. Baked lighting is how most production URP scenes stay readable and cheap: static geometry stores direct/indirect light in **lightmaps**, empty space stores indirect light in **probes**, and reflective surfaces sample **reflection probes** (or the sky). This series walks the full pipeline from light Mode choices through GPU baking, UV hygiene, probe systems in Unity 6, reflections/environment, then Quest budgets and a worked interior+exterior checklist. **Design angle:** Level 9 of [[Level Up! (Review)]] treats lighting and color as theme-park sightlines — landmarks ("weenies"), pacing, and hiding the backstage. Use this series to implement that atmosphere, not only to tick GI boxes. Related: [[URP Shaders and Shader Graph]] · [[HDRP Essentials]] · [[Particle Systems and Layered Effects]] · [[Meta Quest 2]] · [[5.Quest 2 Performance and Rendering]] · [[0.Choosing a Unity Version]] · [[Level Up! (Review)]] ## Reading order 1. **[[1.Realtime Mixed and Baked Lights]]** — Realtime vs Mixed vs Baked; Lighting Modes (Baked Indirect, Shadowmask, Distance Shadowmask, Subtractive); brief HDRP pointer. 2. **[[2.GPU Lightmapper Workflow]]** — Lighting window, Progressive GPU, samples/filtering, Lightmap Parameters, Contribute GI. 3. **[[3.Lightmap UVs and Texel Density]]** — UV2 rules, Generate Lightmap UVs, resolution, Scale in Lightmap, seams. 4. **[[4.Light Probes and Adaptive Probe Volumes]]** — classic Light Probe Groups vs APV in Unity 6; when to pick which. 5. **[[5.Reflection Probes and Environment Lighting]]** — baked/realtime/custom probes, box projection, sky and ambient. 6. **[[6.Mobile and Meta Quest Considerations]]** — lightmap size, baked-preferred, APV cost, shadows, overdraw (6.3 LTS). 7. **[[7.Worked Example Interior Exterior Checklist]]** — small interior + exterior bake checklist. 8. **[[8.Lighting Pitfalls]]** — double lighting, missing probes, pink lightmaps, Quest light overdraw. ## Mental model ``` Lights (Mode: Realtime | Mixed | Baked) │ ├─ Realtime ──► shadow maps / additional lights every frame │ └─ Mixed/Baked ──► Progressive GPU bake │ ├─ Lightmaps (static Mesh Renderers, Contribute GI) ├─ Light Probes or Adaptive Probe Volumes (dynamic / non-lightmapped) └─ Reflection Probes (specular environment) ``` ## Setup checklist (do once per project) 1. Create or open a **URP** project on the version appropriate to your target (6000.5+ desktop tutorial work; **6.3 LTS** for Quest). 2. Confirm **Window > Rendering > Lighting** opens and a **Lighting Settings** asset is assigned to the scene (Lighting window > Scene tab, or create via the New Lighting Settings control). 3. On the URP Asset: note **Lighting > Light Probe System** (Legacy Light Probes vs **Adaptive Probe Volumes**) — part 4. 4. For reflections with Box Projection: enable **Lighting > Reflection Probes > Box Projection** on the URP Asset (required in addition to the probe checkbox). See part 5. 5. Folder suggestion: `Assets/Lighting/` with `Lightmaps`, `LightmapParameters`, `ReflectionProbes`, `Scripts`. ## Official docs hub (cited throughout) - [Lighting Mode](https://docs.unity3d.com/6000.0/Documentation/Manual/lighting-mode.html) - [Set the Mode of a Light](https://docs.unity3d.com/6000.0/Documentation/Manual/LightModes.html) - [Optimize baking (Progressive GPU)](https://docs.unity3d.com/6000.0/Documentation/Manual/GPUProgressiveLightmapper.html) - [Lightmapping settings reference](https://docs.unity3d.com/6000.0/Documentation/Manual/Lightmaps-reference.html) - [Generate lightmap UVs](https://docs.unity.com/en-us/engine/6000.0/manual/lighting-overview/direct-and-indirect-lighting/lightmapping/lighting-gi-uvs/generating-lightmapping-uvs) - [Light Probes](https://docs.unity3d.com/6000.0/Documentation/Manual/LightProbes.html) - [Adaptive Probe Volumes (APV) in URP](https://docs.unity3d.com/6000.0/Documentation/Manual/urp/probevolumes.html) - [Use Adaptive Probe Volumes](https://docs.unity3d.com/6000.0/Documentation/Manual/urp/probevolumes-use.html) - [Reflection Probe Inspector](https://docs.unity3d.com/6000.0/Documentation/Manual/class-ReflectionProbe.html)