Stylized Water 2
There really is no shortage of ideas, and there are still plenty of things I want to work on! These are some features that are slated for R&D or are in an early stage. A general design principle if that everything should remain plug & play, and can be disabled entirely to avoid a performance impact for unused features.
Material editor update. Support for multi-selection will be added, allowing a single property to be modified across multiple materials.. And in turn also enables support for the upcoming Material Variants. This is necessary for futureproofing the asset.
- This requires some breaking changes. Some material parameters will revert to their default values (all materials included in the asset will be corrected!).
Buoyancy update. Slight rework of the API, so that it returns a struct (containing wave height and normal).
- Improved waves, by using a precomputed set of parameters.
- Coupling of vertical movement with horizontal movement. Higher waves should means that they start to create crests.
- Addition of a “Global Water Level” component. Script using the Buoyancy API can up to use this as a reference for the water level.
Features that are complex, and require a sizeable amount of development time will be published as separate paid extensions. Rather than making a single high priced asset, the intend is to keep things modulair.
In order of importance/completion:
Surface Modifiers (extension asset)
A decal-like system that allows the water surface Albedo/Displacement/Normals/Foam to be modified. They are projected from a top-down perspective onto the water surface. It is comparable to Deferred Rendering, which also means the water shader just has to sample a few textures. Modifiers can be made as complex as you see fit.
This opens to the door to virtually unlimited effects. Static textures or custom shaders can be created using Shader Graph to control the behaviour of what a modifier does. These could be used to create:
– Ocean waves (and localized waves)
– Water ripples through particles
– Boat wakes
– Shoreline waves
– Advanced rivers with dynamic flow directions
– Debris floating on the water (duckweed, grime, oil spills, blood, etc…)
Modifiers are rendered using a custom Cascaded rendering system. Which allows for high resolution near the camera, whilst also supporting large rendering distances.
Displacement height to normal map conversion
Allow one modifier to output to multiple layers (eg. both displacement and foam)
Instanced rendering with culling (should be no more than 16 draw calls at maximum quality)
• Option for a modifiers to be “global” and fill up the entire view (eg. ocean waves)
• Shader Graph node to read Displacement/Normal from other modifiers (eg. foam based on height, or surface curvature)
• Support for custom meshes (rather than just a quad). Could be used to create spline-based shorelines.
Support for particle systems
Stretch goals (or post-release)
• Displacement readback in C# for buoyancy effects (working prototype!)
• Compute shader-based particle system, spawns particles on wave crests
Interactive water (extension asset)
A personal favorite, an approximated wave simulation is run based on the shape of meshes that touch the water, allowing small-scale waves to be dynamically created. Similar to what’s seen in games such as The Witcher 3 or Assassin’s Creed https://twitter.com/_staggart_/status/1371390591645401088.
This goes beyond simply rendering particle effects into the water, which wouldn’t support waves bouncing off each other, or having entire 3D shapes create waves (character limbs or boats).
Needs conversion to a compute shader, since this opens up the possibility of reading back the wave height in C# for the buoyancy API.
• (Vital) Render area should move with the camera, and the simulation should account for the shift (open world usage)
• Still needs a form of collision detection, so objects above/below the water don’t render into the simulation.
• Adding a dedicated foam layer to the shader, drawn only through a separate foam simulation.
• Motion vectors, tells the simulation in which direction the object (or rather a pixel) is moving, and how fast. This should make directional waves possible, next to velocity-based foam. This will also allow waves to be created when an object is translated through rotation.
Flowmap painter (extension asset)
Create a flowmap object, with a specific box-size and enables you to paint a flow map within this area. The painter is GPU based, so isn’t per-vertex, and allows for greater detail. This allows the use of brushes (modeled after Substance Painter).
Splines can be used to drive the flow, next to manual painting. But this specific feature would be rebuilt on Unity’s native spline tool when it releases.
Rather than using a 2 colors to set the deep and shallow color, a gradient can be used.
Water projectors (extension asset)
Will allow decal-like objects to render into the water. Likely only albedo and normal maps! https://twitter.com/_staggart_/status/1327268494837239810.
Down the line this can be used to add details such as debris, duckweed or pipe in a custom material that draw shoreline waves with foam (though using Shader Graph only alpha-tested shaders will work). Potentially also possible to use “height projectors”, which can inject a heightmap to raise or lower the water geometry.
currently only works in a specific area with wave support. Or everywhere, but without waves (at which point just placing a sprite above the water looks identical!). Need to find a way to combine best of both worlds.
Underwater rendering (extension asset)
Allows a camera to be partially submerged, and draws a waterline effect on the camera lens. Underneath the water surface, fog and caustics are drawn and the water refracts the scene above the water.
Dynamically subdivides the water geometry to create more vertices near the camera. This allows to have very detailed waves near the camera, without needing a high-poly mesh.