Projected Caustics for Modern Pipelines
The Water Caustics Effect for URP Unity 1.1.3 is a masterclass in efficient shader design for the Universal Render Pipeline. Instead of relying on expensive Render Features or custom scripts that clutter the inspector, it uses a triplanar world-space projection. This means you can drop a cube with this shader into your scene, and it will automatically project caustic light patterns onto any geometry inside its bounds. It’s an elegant solution for developers who need high-quality underwater lighting without the performance tax of real-time volumetric lights.
Integration Tips
The most important step is ensuring that Depth Texture and Opaque Texture are enabled in your URP Asset settings. Without these, the surface normal masking and depth-based fading won’t function. Keep in mind that URP currently limits shadow masking to the main directional light; if your scene relies heavily on point lights for caustic effects, you may need to bake those into your textures instead. To optimize performance, use the provided noise textures to find a balance between visual complexity and texture memory, especially if you are targeting mobile hardware.
Best Use Cases
- Underwater Exploration Games: The chromatic aberration and triplanar projection create a convincing “sunlight through water” look that moves realistically across seabed terrain and shipwrecks.
- Stylized Architectural Pools: Perfect for luxury villa scenes where you need caustic reflections on pool walls and floors without adding heavy light sources.