Water System – Physics, Wakes, & Waves

Water System makes water part of your gameplay instead of a backdrop. Every wave, wake, current and flood is real water that physics, rendering and audio all agree on. A passing boat's wake rocks moored boats far behind it, rain turns a dry basin into a lake that barrels float on, and a dam break floods a valley and carries the cargo away. All of it is deterministic, saveable and network ready.

Wakes and Boats
- Real Kelvin wakes: the true 19.5° wake of real water, computed from hull speed, length, beam and draft, and shared exactly by physics and rendering.
- Wakeboarding physics: boards plane on water pressure, cut across the wake on their edge and launch off its lip.
- Wakes with memory: when a boat turns, its wake rolls on along the old track and rocks floating objects long after the boat has gone.
- Boat engines: thrust curve, ventilation, cavitation, rudder, cruise control and propeller wash that pushes floating objects away.
- Planing and slamming: hulls get lift from water pressure, slam into waves and launch off wakes.
- Flooding compartments: breach a hull and water pours in until the boat trims down and sinks, unless it is pumped out.
- Mooring and anchors: lines go slack, pull taut and part; anchors drop, hold and drag.

Oceans and Waves
- FFT and Gerstner oceans: thousands of waves from a physical, wind-driven spectrum that builds up and calms down smoothly.
- Endless oceans: no edges anywhere, detailed near the camera and coarse at the horizon.
- Wind and gusts: cat's paw gust patches drift across the sea, with spray and whitecaps in strong wind.
- Breaking surf: waves steepen over the shallows, curl into white water and wash foam up the beach.
- Constant-cost queries: GPU readback makes a surface sample about 0.5 µs, however many waves there are.

Rivers and Waterfalls
- Spline rivers: width, depth and flow per point, carved into your terrain with painted banks.
- Physical currents: fastest at the centre, slow at the banks, with foaming rapids where the water runs fast.
- Seamless joints: rivers flow out of lakes, into other rivers and out to sea with no visible edge.
- Waterfalls: falls find the water below on their own, churn their plunge pools and carry logs over the lip.

Rain, Floods and Ice
- Rain that fills the world: rain runs downhill and collects as puddles, ponds and lakes that things float in, then dries up again.
- Rain zones: tanks, cisterns and ponds that fill, overflow and drain.
- Floods and dam breaks: a GPU shallow-water simulation spills across terrain and around buildings, with a rolling, foaming front.
- Breakable ice: walk on ice as thick as the load needs; heavy impacts break it into real floes that float away.
- Cut, melt and refreeze: carve holes and channels like CSG, and melt or freeze the ice at run time.

Buoyancy and Physics
- Exact buoyancy: voxelized bodies roll, pitch, right themselves and capsize naturally; set a density and they float at the right depth.
- Drag and currents: currents, river flow and wave motion carry floating objects, stable at any time step.
- One query API: points, boxes, spheres and capsules get exact submersion on every water type.
- Hundreds of bodies: distance LOD and sleeping keep hundreds of floating objects at 60 FPS.
- Dry interiors: clip volumes make dry hulls, habitats, moon pools and diving bells.

Rendering
- Rich shading: Fresnel reflections, sun glint, refraction, depth color, crest scattering and soft edges.
- Reflections: built-in screen-space reflections and planar reflections for mirror-like water.
- Persistent foam: foam from crests, surf and wakes drifts with currents and fades slowly.
- Objects make waves: bow waves, rings and wakes that bounce off shores and cross each other.
- Underwater: fog with a true half-submerged waterline, Snell's window, caustics, sun shafts and drifting particles.
- Wet surfaces: shores darken where waves wash up, and objects stay wet after leaving the water.

Sound
- Physics-driven splashes: impact speed and displaced volume decide how loud each splash is and which sound it uses, from a plop to a heavy splash.
- Living soundscape: engines, propeller churn, hull slaps, rivers, waterfalls, surf, wind and rain.
- Underwater muffling: a smooth change at the waterline to a muffled underwater mix.
- Smart 'voice' pool: important sounds get the voices first, and bursts merge so 18 crates make one big splash.
- Bring your own audio: a swappable backend for FMOD or Wwise, or delete the optional audio layer entirely.

Multiplayer, Saving and Big Worlds
- Deterministic: one seed and a shared clock give identical water on every machine, with no state streamed.
- Save and load everything: the sea, boats, wakes, ice, floods and every floating object, in one call.
- Network sync: about 150 bytes per floating object for live updates, with no allocations.
- Floating origin: double-precision water stays exact 10,000 km from the start. Supports origin shifting.
- Sea codes: share a short text code and anyone gets the same sea.

Tools and Customization
- Water Designer: tropical, North Atlantic, alpine lake and murky swamp presets with live tuning; save your own looks and blend between them at run time.
- Lakes from an outline: draw a shore on your terrain and build the whole lake in one step.
- Fully moddable: hooks on every system to modify or veto behaviour, and adapters for the clock, wind, waves and audio.
- Editor tools: creation menus, handles, gizmos, a debug window and an in-build debug overlay.
- Eighteen demo scenes: wakeboarding, floods, rain, harbour, frozen lake, waterfalls, endless ocean and more, all with sound.