GPU shallow-water and sand simulation sandbox: real waves, erosion, sandcastles, digging tools, draggable rocks and floating props. Compute-based, mass-conserving, Unity 6.SandFlow turns a patch of your scene into a living beach diorama: a real-time GPU shallow-water solver coupled to granular sand transport, running entirely in compute shaders.WATER. A mass-conserving shallow-water core (Rusanov flux, positivity-preserving reconstruction) drives waves, surf, swash and backwash. Procedural wave dressing, caustics, foam, whitecaps and spray render on top of the simulated surface. Water level, wave amplitude, drift ripple and more are tunable live.SAND. Sand erodes, travels with the flow and settles: dig channels, watch the sea carve the shore, build dams and watch them fail realistically. Wet sand darkens and smooths; dry sand keeps wind ripples.INTERACTION. A full toolset ships in the demo: a shovel that scoops and pours real volume, castle stamps, terrain brushes, cannons, draggable rocks and props that displace water honestly and leave prints that heal, plus floating objects with buoyancy and wakes.TUNING. An in-game control panel exposes the simulation and look parameters, with persistent settings, map presets (beaches, rivers, lagoons, atolls) and camera controls.Ships as clean C# + compute/HLSL source with a complete interactive demo scene and a standalone-build entry point. Desktop platforms with compute shader support (DX11/DX12, Vulkan, Metal).Real-time GPU shallow-water solver (compute shaders), exactly mass-conservingCoupled sand erosion, transport and deposition with wet/dry shadingProcedural wave dressing, caustics, foam, whitecaps and sprayInteractive tools: volumetric shovel, castle stamps, terrain brushes, cannonsDraggable rocks and props displace water honestly; prints heal when movedFloating objects with buoyancy and wakesIn-game tuning panel, persistent settings, 25+ map presetsFull C# and compute/HLSL source, interactive demo scene, standalone build entryRender pipelines: Built-in, URP 17 and HDRP 17 on Unity 6000.3Requires compute shader support: DX11/DX12, Vulkan or Metal, desktop platforms
