Water Shader

Overview

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

Updates seen in CRYENGINE 3:

  • Surface is no longer using procedural bump map, but instead FFT noise based gradient/normal/height map with multiple frequencies/scales for ambient waves.
  • User interaction with 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 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 where carefully crafted to give a 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 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.
Ocean vs Water
  • When setting up water materials for 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

Detail Normals 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 soft intersection, but blending foam on intersection regions.

Foam

Foam tilling

Tiling amount for foam.

Foam

Fresnel bias

See Illum Shader for more information. For water a good value is 0.05 (default value).

Default

Fresnel power

See Illum Shader for more information.

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

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

Default

Tilling

Set waves bump tilling.

Default

Watevervol flow speed

Set the flow speed for the water volume flow map.

Water Volume flow

Using the Water Shader

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

Some examples of look:

Tiling - too little

Tiling - on the spot

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