Analytical Volumetric Lighting [URP] - Performant Raytraced Volumetric Lights

Analytical Volumetric Lighting is a post-processing render feature intended to replicate the behavior of the volumetric lighting focusing on high performance and high real-time light count. This is achieved thanks to the analytical approach which makes per-light calculations constant-time. Instead of estimating air light integrals with raymarching, they are calculated precisely.

PERFORMANT - Made to be much more performant compared to the traditional raymarching volumetric lighting solutions. Based on the analytical approach, render up to thousands of volumetric lights at the same screen with frame times compared to SSAO* even on mobile platforms**.

REALISTIC - Lights behave similarly to the real world based on the inverse square law. This provides you with high-fidelity lighting with no spatial limits or approximation noises.

SIMPLE TO USE - A single Volumetric Light component to make the setup as easy as possible. All of the lighting parameters are named to be intuitively familiar assisting artists during scene creation.

CUSTOMIZABLE - Take control of what you're trying to achieve - whether it's a highly stylized game or a realistic demo showcase. This package contains source code with comments to assist with any further code customization.

Main Features 🌟

• Clustered Rendering: Similarly to Forward+ rendering, lights are divided into clusters greatly lowering the rendering time required. Depth Culling feature makes use of the depth texture, culling lights behind walls and skipping unwanted calculations.
• Upscaling Feature: Render at native 25% resolution (or any other) for a substantial performance boost.
• No Draw Distance Limit: Draw distance is not limited compared to the raymarching solutions due to the analytical light equation solution. Render both close and far lights with the same fidelity at the same time.
• No Noise Filtering: As raymarching is not being used, lights produce highly accurate values with no filtering required. This deeply improves lighting fidelity with no performance trade.
• Deep Customization: Several useful parameters for each of your lights. Choose between light color and light temperature. Apply scattering parameter for the 'blurred' light sources.
• Realistic Shapes: 7 Light Shapes, including Point, Spot, Area, Uniform lights with more to come in the future.
• Mask Volumes: Limit volumetric fog to box & sphere volumes with a simple drag'n'drop component setup.
• Global Fog: Use a custom global fog feature including a light scattering parameter highly increasing the believability of your game.
• Distance Culling: Cull your volumetric lights based on camera distance with a smooth falloff.
• Debug Overlay: Easy-to-use overlay to help you determine performance problems and other information.
• Both Deferred and Forward rendering are supported!
• Both Perspective and Orthographic camera projections are natively supported!
• All the changes are applied instantly & viewable in Editor and Scene views.
• Documentation & Full Source Code are available

Please note that there is no shadow sampling (therefore, volumetric shadows as such) as this is not possible with an analytical approach!

Compatibility 🪄

• Unity 2021.3 or later.
• URP is supported; Built-In, HDRP are not supported.
• Forward, Forward+, Deferred rendering paths are supported.
• Mobile Vulkan is partially supported**.
• Mobile OpenGLES is not supported (Coming later).
• VR is not supported (Coming later).
• DX11, Vulkan, OpenGLCore, Nvidia/AMD/Intel are supported.
• Transparency is not supported (Coming later).
• Shadows are not supported.

Demo Builds on GitHub

GitHub Issues Repository

Documentation on Coda

* - SSAO included in URP with default settings.

** - Mobile platform support might be limited at the moment. Use at your own risk.

Assets (3D models & textures) shown in the screenshots are not included.