Shallow Water Simulation

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Runs a shallow water simulation at global sea level in a domain around its transform, and injects the results of the simulation into the water data.

Related: Shallow Water Simulation

Properties

General

Preset	Preconfigures the simulation for a specific use case. Requires resetting the simulation.
None	All options available.
Shoreline	Only shows options for shorelines.
Stream	Only shows options for streams.
Width	The width of the simulation area (m). Enable gizmos to see a wireframe outline of the domain. Requires resetting the simulation.
Depth	The depth of the water in the shallow water simulation (m). Any underwater surfaces deeper than this depth will not influence the sim. Large values can lead to instabilities / jitter in the result. Requires resetting the simulation.
Placement	Where the simulation is placed. The default performs the best.
Fixed	The component is in a fixed position.
Transform	The component follows the transform.
Viewpoint	The component follows the viewpoint.
Place At Sea Level	Places the simulation at sea level. Requires resetting the simulation.
Friction	Friction applied to water to prevent dampen velocities.
Dynamic Seabed	Recompute ground heights every frame. Only enable this if terrain used by water system changes at runtime.
Sample Depth Probe Directly	Whether to sample the Depth Probe directly. If disabled then data will come from the LODs which will have precision losses depending on camera position. Only disable if necessary. Requires resetting the simulation.
Sample Water Level Inputs Directly	Whether to sample water level inputs directly. If disabled then data will come from the LODs which will have precision losses depending on camera position. Only disable if necessary. This option only supports water level inputs using the Geometry, Spline or Renderer modes. Requires resetting the simulation.
Additional Water	Adds meters of additional water into the simulation domain on initialization. Requires resetting the simulation.
Drain Water At Boundaries	Rate at which to remove water at the boundaries of the domain. Useful for preventing buildup of water when simulating shoreline waves.
Evaporation	Rate at which to remove water at any location. Useful for removing remaining water from lowering tides.

Source Blending

Depth Range

Affects depth-based blending of the simulation and animated waves (m). For the minimum, when the water depth is less than this value, animated waves will not contribute at all, water shape will come purely from this simulation. For the maximum, when the water depth is greater than this value, this simulation will not contribute at all, water shape will come purely from the normal ocean waves. Negative depths are valid and occur when surfaces are above sea level.

Push Up Strength

The intensity at which waves inject water into the simulation.

Distance Culling

Enable	Disable simulation when viewpoint far from domain.
Cull Distance	Disable simulation if viewpoint is more than this distance outside simulation domain.
Cull Transition Speed	The speed of the transition to its culled state.

Stability

Time Step	Time step used for simulation (s). Smaller values can make simulation more stable but requires more runtime computation.
Courant Number	Stability measure - limits velocities. Default 0.5.
Overshoot Reduction Strength	Overshoot is artifacts where the water will spike sharply.

Quality

Texel Size	Simulation resolution - width of simulation grid cell (m). Smaller values will increase resolution but take more computation time and memory, and may lead to instabilities for small values. Requires resetting the simulation.
Maximum Resolution	Maximum resolution of simulation grid. Safety limit to avoid simulation using large amount of video memory. Requires resetting the simulation.
Blur Shape For Render	Filters the shape prior to rendering to smooth out sharp features. Always enabled when baking.
Blur Mask Iterations	Filters the mask.

Water Edge Margin

Enable	Adds a margin around the water level to prevent water from degenerating at a distance and prevents water wall creep (px).
Margin Width	Width of the margin. The default is the optimal width.
Margin Width (Baked)	Same as Margin Width but for baking only. Will use the larger value of the two.

Output

Mode	Whether to use the baked textures. Only supported by water level.
Real Time	Simulate every frame.
Baked	Simulation output has been baked to a texture.

Shape

Inject	Add the resulting shape to the water system. If blending data from waves or height then use Waves or Level respectively. Requires resetting the simulation.
Waves	Inject into the Animated Waves.
Level	Inject into Water Level.
Baked Texture	The baked texture for water level.
Report Maximum Displacement	Inform water how much this input will displace the water surface vertically. This is used for culling water tiles.
Domain Padding	Padding area for zero activity at the edge of the domain. Adds padding so that simulation edge can overlap with height inputs without causing a seam (m). It is important that the padding fully overlaps the water level input, or there may be a gap. Visualized by the gizmo.

Flow

Inject	Add the resulting flow velocities to the water system.
Baked Texture	The baked texture for flow.
Strength	Multiplies flow output to scale when injecting.

Foam

Inject	Add the resulting foam to the water system.
Baked Texture	The baked texture for foam.
Strength	Multiplies foam output to scale when injecting.