Water Shader

Overview

Water is a relatively complex natural phenomenon to achieve in real-time rendering, due to its many little contributing factors both visually and physically.

Basic Information for Water Shader:

Surface is no longer using a procedural bump map, but instead, FFT noise based gradient/normal/height map with multiple frequencies/scales for ambient waves.
User interaction with the surface will generate waves propagation.
For high specs, we keep using vertex displacement, with added support for water interaction.
Cheap approximation for sun shadows.
Separate water fog passes have been merged into water surface rendering for optimal performance.
One final small step forward was unifying water rendering, this means ocean, water volumes and rivers can go through same final rendering path - which will be easier for artists/designers to use since both are setup in the same way.

Water rendering in action for high spec. Vertex displacement gives an extra visual kick


Water rendering in action for consoles specs, using parallax approximation

Dynamic water interaction

Some Water Properties

Notice where does main water color/look comes from: It's all coming from reflection on water top surface and how light interacts with water molecules/suspended particles (we call it "underwater fog" on CRYENGINE).

This means never try to achieve water color/look just with reflection, it's a sum of both.


Notice on both images bright highlights comes from the sky reflection, mostly at sharp angles or in bright reflection spots.	Notice second look contributor: the "water fog", greenish on the first image, brownish on second. This color comes from many factors, including algae/dust/plankton among others.

Guidelines for Setting Up Water

Default parameters were carefully crafted to give an initial nice default look, but every level is a different level, so some fine tuning will always be required.
Never, never try to achieve water color/look just with reflection, it's a sum of both that gives you a final correct look.
Since one of your 2 main look contributors is reflections, if you have a Dull looking environment, you'll get dull/boring looking reflections. Always strive for interesting sky look, with nice skyline gradient and bright spots (last one particularly important for night scenes).
Use foam carefully, this is a cheap approximation - don't overdo it, else might look out of place.
Ocean reflection draw distance is tied to the terrain detail texture draw distance.

When setting up water materials for an ocean, ensure water volume option is not checked.
When setting up water materials for water volumes or rivers, ensure water volume option is checked.

Shader Params

Shader Params	Description	Shader Gen Option
Crest Foam Amount	Set amount of foam that will appear at the crest of a wave (FFT displaced ocean only - Very High Spec). Foam shader generation parameter must be enabled first.	Foam
Detail Normals Scale	Allows you to set normal scale.	Default
Detail Tilling	Set waves detail bump tilling.	Default
Fake camera speed	Causes the surface of the water to scroll in world-space. This gives the impression that a stationary object in the ocean is actually moving through it.	Fake camera movement
Foam amount	Multiplier for foam.	Foam
Foam soft intersection	Very similar to a soft intersection, but blending foam on intersection regions.	Foam
Foam tilling	Tiling amount for foam.	Foam
Fresnel Gloss	The gloss of the Fresnel effect. See Illum Shader for more information. For water, a good value is 0.05 (default value).	Default
Gradient scale	Use for giving a more choppy look to waves (scale for parallax mapping for xy plane).	Default
Height scale	Set scale for heightmap used for parallax mapping approximation.	Default
Normals scale	Overall scale for normals.	Default
Rain ripples tilling	Sets tiling for rain ripples.	Default
Reflection bump scale	Reflection map bump scale.	Default
Reflection scale	Real-time reflection map multiplier / or cube map multiplier for water volumes.	Default
Refraction bump scale	Refraction map bump scale.	Default
Ripples normals scale	Sets dynamic ripples normals scale.	Default
Soft intersection factor	Set water soft intersection with geometry.	Default
SSS scale	Sets the SSS scale.	Default
Tilling	Set waves bump tilling.	Default

Shader Generation Parameters

The following Shader Generation Paramaters are available for the Water Shader:

Parameter	Description
Sunshine	Enables sunshine effects on the ocean surface.
Fake Camera Movement	Enables fake camera movement for scenes in the ocean.
No Refraction Bump	Disables refraction bump.
Foam	Enables foam on the ocean surface.

Using the Water Shader

Every parameter is straightforward to use, and what the name says is basically what it does. In case of setting up water volumes, simply increase tilling scale.

Some examples of look:

Tiling - too little	Tiling - just right	Tiling - way too much (kills look)


Reflection setup (bias 1) Mirror Look. No underwater fog visible at all	Reflection setup (default bias 0.05) reflections and underwater fog clearly visible	Reflection setup (reflection scale) Too little, kills look

Normals setup (low normal scale)	Normals setup (normal scale) Note all the little surface variations/details)	Normals setup (inc. detail normals scale) Too much detail kills look

Performance guidelines

Only enable options you really want to use:

Do you need sun reflection? If not, disable.
Do you need foam? If not, disable.
Set caustics multiplier to 0 to disable caustics rendering when not needed.

Performance related CVars:

e_WaterOcean

Activates drawing of ocean. 
1: use usual rendering path
2: use fast rendering path with merged fog

e_WaterVolumes

Activates drawing of water volumes
1: use usual rendering path
2: use fast rendering path with merged fog

r_WaterReflectionsQuality
DUMPTODISK

Activates water reflections quality setting.
Usage: r_WaterReflectionsQuality [0/1/2/3]
Default is 0 (terrain only), 1 (terrain + particles), 2 (terrain + particles + brushes), 3 (everything)

r_WaterUpdateFactor
DUMPTODISK

Distance factor for water reflected texture updating.
Usage: r_WaterUpdateFactor 0.01
Default is 0.01. 0 means update every frame

Documentation