Version: Unity 6.1 Alpha (6000.1)
Language : English
Introduction to lighting
Light sources

Choose a lighting setup

Choose a global illumination system

Warning

The Unity Editor and Player allow you to use both EnlightenA lighting system by Geomerics used in Unity for Enlighten Realtime Global Illumination. More info
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Realtime Global IlluminationA group of techniques that model both direct and indirect lighting to provide realistic lighting results.
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and baked lighting at the same time.

However, simultaneously enabling these features greatly increases baking time and memory usage at runtime, because they do not use the same data sets. You can expect visual differences between indirect light you have baked and indirect light provided by Enlighten Realtime Global Illumination, regardless of the lightmapperA tool in Unity that bakes lightmaps according to the arrangement of lights and geometry in your scene. More info
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you use for baking. This is because Enlighten Realtime Global Illumination often operates at a significantly different resolution than Unity’s baking backends, and relies on different techniques to simulate indirect lighting.

If you wish to use both Enlighten Realtime Global Illumination and baked lighting at the same time, limit your simultaneous use of both global illumination systems to high-end platforms and/or to projects that have tightly controlled scenesA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
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with predictable costs. Only expert users who have a very good understanding of all lighting settings can effectively use this approach. Consequently, picking one of the two global illumination systems is usually a safer strategy for most projects. Using both systems is rarely recommended.

Lighting scenarios

Now that we have introduced the render pipelinesA series of operations that take the contents of a Scene, and displays them on a screen. Unity lets you choose from pre-built render pipelines, or write your own. More info
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and the main lighting features, let’s have a look at a few examples of projects and see which settings could be used to light them. Since every project is unique, you might use slightly different options based on your requirements.

1. Prototype or quick previsualization

If you rely heavily on the Asset StoreA growing library of free and commercial assets created by Unity and members of the community. Offers a wide variety of assets, from textures, models and animations to whole project examples, tutorials and Editor extensions. More info
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to build your prototype, the Built-In Render Pipeline could be the only suitable render pipeline, as most assets found on the Store are not fully compatible with HDRP and URP; nonetheless, asset compatibility will improve over time. If you are building all the assets from the ground up and already have a clear idea of your project’s requirements, then you could pick one of the two SRPs (i.e. URP or HDRP) or even create a custom one.

When you are in the early stage of (pre-)production and need a quick turnaround and maximum flexibility for the lighting, you might prefer a full real-time approach that does not require any precomputation, therefore you might want to turn off both Baked Global Illumination and Enlighten Realtime Global Illumination. To alleviate the lack of proper indirect lighting, you can enable Screen Space Ambient OcclusionA method to approximate how much ambient light (light not coming from a specific direction) can hit a point on a surface.
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: it can help ground the object in the scene by offering cheap real-time contact shadows.

2. 3D Mobile strategy game

If you are targeting mobile devices, URP could be a great candidate to ensure solid performance for your game. It is in many cases possible to customise URP to suit your game’s specific needs, with help from a graphics programmer.

The Built-In Render Pipeline and URP both support ShadowmaskA Texture that shares the same UV layout and resolution with its corresponding lightmap. More info
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Lighting Mode which makes it possible for you to bake shadows for static objects while still enabling dynamic objects to cast real-time shadows. If Shadowmasks are too expensive for your project, you can fall back to the cheapest Subtractive mode. Finally, the forward rendering pathThe technique that a render pipeline uses to render graphics. Choosing a different rendering path affects how lighting and shading are calculated. Some rendering paths are more suited to different platforms and hardware than others. More info
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is probably the best option if you have a very small number of lights in your level(s), and if you’re targeting older hardware.

3. AAA corridor shooter (fixed time of day)

If you are aiming for AAA-quality visuals on PC and consoles for your linear first-person shooter, HDRP should be the preferred render pipeline. Again, with the help of graphics programmers, a custom SRP could also be developed.

If your levels contain many real-time shadow casting lights (e.g. destructible light props and moving lights), then using the Baked Global Illumination system with the Baked Indirect mode should ensure you get great looking indirect lighting from the Mixed directional light and the Baked lightsLight components whose Mode property is set to Baked. Unity pre-calculates the illumination from Baked Lights before runtime, and does not include them in any runtime lighting calculations. More info
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in static light props. If your levels consist of a larger proportion of fixed shadow casting lights, then an approach with Shadowmasks could be recommended because HDRP offers a great hybrid Shadowmask mode which gives you more control over the blend between real-time and baked shadows.

If you also plan to support the Nintendo Switch, then using URP would be recommended, so that you can support most gaming platforms on the market and not having to go through the potentially tedious process of porting your project from HDRP to URP, or vice versa.

4. Battle Royale (day-night cycle)

If you plan to release a battle royale game for PC and consoles, that features large-scale environments and fully dynamic lighting, you should select HDRP, or extend it to tailor the rendering pipeline to your project. You could consider URP if you are not aiming for AAA visual fidelity and are targeting mobile devices or systems with lower specifications.

For this particular scenario, if you are using the Built-in Render Pipeline, activating both the Enlighten Realtime Global Illumination and a Baked Global Illumination system is not recommended, because the resulting overhead in terms of performance and scene management for an immense level could be problematic. Another argument against the use of both global illumination systems is the unpredictable nature of such large-scale multiplayer games: performance estimations are for instance more difficult than in a highly-scripted linear level.

Additional resources

Introduction to lighting
Light sources