How to Bake Ambient Occlusion Maps

Realistic lighting is crucial to the visual appeal of your scenes. One powerful technique that can significantly improve the quality of your lighting is ...

baking ambient occlusion (AO) maps. This blog post will walk you through the baking process of ambient occlusion maps, explaining what they are, why they're important, and how to complete them step by step using some common industry tools.

---

1. What is Ambient Occlusion?
2. Why Bake Ambient Occlusion Maps?
3. Tools for Baking Ambient Occlusion Maps
4. Conclusion

---

1.) What is Ambient Occlusion?

Ambient occlusion (AO) is a lighting technique that simulates how much ambient light is received by a particular point on an object or surface based on its surrounding geometry. It helps to give your scenes more depth and realism by determining how shadows are cast due to nearby geometry, even when no direct light is present. This effect can make flat surfaces look less flat and provide better lighting in areas where you might not have enough lights.

---

2.) Why Bake Ambient Occlusion Maps?

Baking ambient occlusion maps involves pre-computing the AO values for your scene and storing them as texture maps. This has several advantages:
1. Performance: Real-time baking can be computationally expensive, especially in larger scenes. Baked AO maps allow you to use much less CPU power during gameplay by using a texture lookup instead of real-time computation.
2. Consistency: Inconsistent lighting due to dynamic shadows and reflections can be jarring for the player. Baking ensures that your lighting is consistent across different renders, even if some objects move or change position.
3. Artistic Control: With baked AO maps, you have more control over how lights interact with surfaces because you can tweak the settings before finalizing them in-game.

---

3.) Tools for Baking Ambient Occlusion Maps

There are several tools available that support baking ambient occlusion maps, each with its own features and workflows:

1. Unity

Unity's built-in lighting system supports real-time GI (Global Illumination) which includes baked AO. Here's how you can do it:

- Setup Your Scene: Ensure your scene has enough lights to create realistic shadows and ambient occlusion should be enabled in the Lighting Settings under `Edit >> Project Settings >> Graphics`.

- Enable Baked Global Illumination: Go to `Window >> Rendering >> Lighting Data` and enable baking. You can then adjust the resolution, samples, and other settings based on your scene complexity.

- Bake and Apply: Use the button provided in Unity's UI or manually trigger a bake from the menu (`GameObject >> Light >> Generate Lighting Data`) to generate AO maps which you can then apply as needed.

2. Substance Painter

Substance Painter is not only a powerful texturing tool but also includes features for baking various types of textures including ambient occlusion:

- Prepare Your Model: Ensure your model has high enough polygon count and proper UV mapping to capture detailed geometry.

- Create AO Maps: Use the -Baking- tab in Substance Painter where you can choose from several methods to compute ambient occlusion based on normal maps, displacement maps, etc. Adjust settings like bake resolution and scale according to your model's needs.

- Export and Apply: Export the generated texture as a PNG or JPEG and import it into your game engine or VFX software for use in rendering.

3. Marmoset Toolbag

Toolbag is another tool that supports baking ambient occlusion:

- Set Up Your Scene: Create or load your scene, ensuring you have appropriate materials applied to capture lighting effects correctly.

- Baking Workflow: In the Toolbag UI, navigate to the -Render- tab where you can find settings for AO and other render properties like reflections and shadows. Adjust these according to your artistic needs, and then click to bake.

- Exporting: Export your rendered output or directly use it in further processing within Toolbag or as a texture in Unity or other engines.

---

4.) Conclusion

Baking ambient occlusion maps is an essential step for creating realistic lighting in games and visual effects. Whether you are using Unity, Substance Painter, or Marmoset Toolbag, the process involves setting up your scene, choosing appropriate tools to compute AO, and then applying these textures during rendering to enhance realism without heavy computational costs. Experiment with different settings and methods to find what works best for your project's style and complexity.

---

The Autor: TerminalCarlos / Carlos 2025-05-29