/WaterRW

WaterRW is 2D interactive water system for Unity.

Primary LanguageC#MIT LicenseMIT

WaterRW

日本語版

WaterRW is 2D interactive water system for Unity.

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Requirements

  • This project is made with Unity 2020.3.12f1.
  • By default, Burst package is required.

Quick Start

  1. Download WaterRW.unitypackage from releases page.
  2. Install Burst package from Package Manager.
  3. Add Ruccho/Water-RW/Prefabs/Water-RW (Compute).prefab to your scene.

Water-RW prefab is composed of WaterRWCompute script, MeshFilter, and MeshRenderer with Water-RW/With Compute material.

Some platforms such as WebGL or old mobile devices don't support Compute Shader. Make sure your target platform does before using WaterRW.

(Legacy implementation with C# Job System is also included in the package but it is no longer supported.)

Material Settings Guide

WaterRW uses the shader Water-RW/With Compute.

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Property Type
Tint Color Tint color.
Pixel Snap Float Same as one in Sprites-Default shader.
Normal A Texture2D Normal map A. Use tiling properties to scale a map.
Normal A Intensity Float Amount of distortion of normal map A.
Normal A Speed Vector Scroll speed of normal map A. Only X and Y works.
Normal B Texture2D Same as normal A.
Normal B Intensity Float Same as normal A.
Normal B Speed Vector Same as normal A.
Background Blend Float Rate of reflection blend.
Transparency Float Dark reflection areas goes transparent.
Multiplier Color Color multiplier.
Addend Color Color addend.
Wave Size in Viewport Space Float Horizontal size of near-surface distortion.
Wave Distance in Viewport Float Vertical size of near-surface distortion.
Wave Frequency by Position Float Frequency of sin curve used for near-surface distortion by vertical position.
Wave Frequency by Time Float Frequency of sin curve used for near-surface distortion by vertical time.
Surface Color Color Color of surface line.
Surface Width in Pixel Color Width of surface line in pixels.
Fade Distance in Viewport Space Float Vertical size of fade to avoid display reflection areas out of GrabPass.

Enable Interactions

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WaterRW supports rough interation with rigidbodies. (Colliders with complex shapes may not be handled correctly!)

In inspector of WaterRWCompute script, select layers to interact with in Layers To Interact With property.

WaterRWCompute Settings

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Property Type
Mesh segments Per Unit float Numbers of mesh divisions per unit.
Update Mode FixedUpdate / Update Timing to calculate wave. Use FixedUpdate to work interactions correctly.
Override Fixed Time Step bool Determine whether to use custom timestep.
Fixed Time Step float Custom time step.
C float The constant used in wave calculation. Increasing this will increase the speed of the waves.
Decay float Coefficient for damping waves.
Enable Interaction float Determine whether to use interaction.
Layers To Interact With LayerMask Layers to interact with.
Spatial Scale float Horizontal scale used in wave calculation.
Max Interaction Items float Max number of rigidbodies to interact with.
Wave Buffer Pixels Per Unit float Resolution of buffers used to wave calculation.
Scroll To Main Camera bool Track the range of the wave calculation to the position of the main camera.
Max Surface width float Max width of the wave in world scale.

Avoid Divergence

Values of Fixed Time Step, C, Spatial Scale and Wave Buffer Pixels Per Unit may cause divergence.

To avoid divergence, keep 0 ≤ (C * dt / dx) ≤ 1.


dt = time step (Fixed Time Step when Override Fixed Time Step is true, otherwise Time.deltaTime or Time.fixedDeltaTime is used)

dx = Spatial Scale / Wave Buffer Pixels Per Unit


Buffer Scrolling

Although the size of the buffer used for wave calculation is finite, interaction with the seemingly infinite surface of the water can be achieved by making the wave calculation range follow the camera position. If Scroll To Main Camera is true, it will automatically follow Camera.main. To set it manually, set the X coordinate to float WaterRWCompute.WavePosition.