GPU Rain VFX — SDF Collision & Surface Physics System · URP & HDRP

━━━━━━━━━━━━━━━━━━━ Tired of rain passing through roofs, buildings, interiors, glass structures and covered areas? This asset is built around that exact problem. Instead of relying on a single collision method, it combines local SDF collision, large-area Roof Masking, Water Masking, Ground optimization and Depth Buffer Collision into one system designed for detailed environmental rain interaction without requiring an expensive world-sized volumetric SDF. Rain can interact with walls, ceilings, roofs, interiors, overhangs, bridges, props, vehicles, moving and rotating SDF Sources, glass structures and other complex geometry — while Splashes, Ripples, Impact Mist and sliding surface particles add secondary interaction after impact. Transparent or visually complex surfaces can also use dedicated hidden SDF proxy geometry while the original rendered mesh and material remain unchanged. A glass roof, for example, can stay visually transparent while a simple hidden SDF proxy provides the collision volume used by the rain. More Than Simple Rain Collision ━━━━━━━━━━━━━━━━━━━ Rain does more than simply disappear when it hits geometry. Surface impacts can generate Splashes, Ripples and Impact Mist, while Splash particles interacting with the local SDF can continue moving along detected surfaces. On suitable sloped geometry, this creates runoff-like motion across roofs, glass and other collision surfaces. Water is handled separately through a dedicated Water Mask, providing the interaction height used for Ripples and water-aware Splash behavior. Key Features ━━━━━━━━━━━━━━━━━━━ 🏠 Rain Occlusion for Roofs & Interiors — block rain beneath buildings, canopies, bridges, overhangs and other cover. 🧊 Local Moving Aquarium SDF — nearby baked SDF Sources are dynamically combined into a runtime Texture3D for detailed local 3D collision. 🌍 Hybrid World Coverage — local SDF provides detailed nearby collision while Roof Masking and Depth Buffer Collision continue handling a much larger surrounding area at lower cost. 🪟 Glass & Transparent Surface Interaction — use hidden SDF proxy geometry for rain collision without changing the original transparent material. 🧩 Custom SDF Proxy Geometry — use simplified or purpose-built collision-authoring geometry for thin, complex or visually expensive meshes. 💧 SDF Surface-Sliding Splashes — impact particles can continue moving along collision surfaces, creating runoff-like behavior on suitable slopes. 🌊 Water Interaction — detect water-surface height, spawn Ripples and prevent normal Splashes from continuing below the water surface. 🌫️ Impact Mist — configurable secondary mist particles add detail to surface impacts. 🔄 Moving & Rotating SDF Sources — baked Sources can move and rotate at runtime without rebaking. 📐 Tiered SDF Sources — use multiple bake-resolution tiers to balance detail, texture usage and runtime cost. ♻️ Reusable Baked SDFs — repeated objects can share the same baked SDF texture while keeping independent runtime transforms. 🎯 Camera & Ground Culling — reduce unnecessary Aquarium processing where full local coverage is not required. 📉 Adjustable Rain Density Outside the Aquarium — reduce distant Drops and their downstream Splash, Ripple and Mist cost. 🛠️ Weather & Water Proxy Tools — generate technical masking geometry without modifying the original object's layers, materials, colliders or scripts. 🧰 Complete SDF Authoring Workflow — SDF Source Marker, SDF Source Baker with Test Bake / Preview, SDF Scene Overview and SDF Source Cleaner. ⚙️ URP & HDRP Setup Assistants — validate project and scene configuration and automatically apply supported fixes. 🎨 Customizable Rain Particles — adjust particle textures, colors, sizes and behavior for Drops, Splashes, Ripples and Mist. 📦 Custom Streaming Support — SDF Sources can also be registered manually for chunked worlds, additive scenes, pooling and project-specific streaming systems. Detailed Collision Where It Matters ━━━━━━━━━━━━━━━━━━━