Env cascade light

CSM in Counter-Strike: Global Offensive

Comparison of CSM and without CSM in Black Mesa
(Click to preview)

It casts an extremely accurate shadow map via the tools/skybox texture, acting as a real-time variation of light_environment. This form of lighting is known as ^[1] Cascaded Shadow Maps], or CSM, which works by rendering very detailed shadow maps which becomes a lower and lower resolution depending on the distance the viewer is from the surface, similar to mipmaps. Some games automatically add this entity to the map, but it can be placed manually as well.

Important:

• Xengine's implementation requires -CascadeShadows and -StaticPropLighting parameters for VRAD, this for CSM to work correctly.
• Due to lighting changes in Xengine, this entity has many additional parameters.

Bug:

• Although you can toggle this entity, you can have only one env_cascade_light in your level. Other will not work.
• In , shadows will be very faint if the map hasn't been compiled with HDR.
• In , Lightstyles will break when this entity exists.  [todo tested in ?]

Note:

• You still need to have a light_environment in your map as well to create lightmap based lighting, which is not done by this entity.
• Source 2013 doesn't have this entity, but there is an ^[2] attempt] of porting it.
• Alien Swarm Deferred's counterpart to this entity is Light_deferred_global(also in )
• You alternatively can implement Lambda Wars's Deferred lighting as it is the most robust implementation currently being available to the public.

Represented by class CCascadeLight.

Keyvalues

Light Color (color) <color255>

This is the color of the sunlight. For , the color is automatically copied from the light_environment.

Max shadow distance (maxshadowdistance) <float>

Maximum dynamic shadow distance. Higher values are slower, default on PC is 400 units.

Use light_environment's angles (uselightenvangles) <boolean>

If true, the CSM shadow angles are automatically taken from a light_environment's angles. If false, this entity's Pitch Yaw Roll is used.

LightRadius1 (LightRadius1) to LightRadius3 <float> (only in )

Used for controlling shadow softness in cascades 1, 2, and 3.

Depthbias1 (Depthbias1) to Depthbias3 <float> (only in )

DepthBias for cascades 1, 2, and 3.

Slopescaledepthbias1 (Slopescaledepthbias1) to Slopescaledepthbias3 <float> (only in )

Slope DepthBias for cascades 1, 2, and 3.

ViewModelDepthbias (ViewModelDepthbias) <float> (only in )

DepthBias for viewmodel cascade.

ViewModelSlopescaledepthbias (ViewModelSlopescaledepthbias) <float> (only in )

DepthBias for viewmodel cascade.

CSM_Volume_Mode (CSMVolumeMode) <choices> (only in )

Use Manual mode for better quality and performance. In near future Auto mode will be removed from the game.

• 0: Auto: Static cache will update once every 10 frames (approx) covering max shadow distance or whole map around player.
• 1: Manual : Static cache area coverage and updates are managed via CSM Volumes' I/O.

Start Disabled (StartDisabled) <boolean>

Stay dormant until activated (with theEnableinput).

Inputs

SetAngles <stringRedirectInput/string>

Sets the direction shadows cast in.

Note:Effects nothing.

LightColor <color255RedirectInput/color32>

Changes color of the sunlight.

Bug:Doesn't work as expected. With Counter-Strike: Global Offensive's implementation, the color only changes on static props, not on world geometry or dynamic objects. It only changes the shadow color (only in world geometry, not in models), with no change upon reloading the game. With Xengine's implementation, the only thing you can do is change shadows color to turquoise and change the intensity of these shadows, however this doesn't effects shadows on the viewmodel.

Examples

Note: Portal 2: Community Edition uses Counter-Strike: Global Offensive's implementation of CSM Counter-Strike: Global Offensive ( Portal 2: Community Edition): Before ent_fire env_cascade_light lightcolor 255 0 0 255. After ent_fire env_cascade_light lightcolor 255 0 0 255. Xengine: Before ent_fire env_cascade_light lightcolor 255 0 0 255. After ent_fire env_cascade_light lightcolor 255 0 0 255.

  [todo tested in ?]

LightColorScale  !FGD 

Deprecated.
Boosts the color of the sunlight. Non-functional, only resets the Light Color.

Bug:Effects nothing in Xengine.  [todo tested in ?]

SetCSMVolume  (only in )

Set CSM Volume via trigger volume.

SetCSMVolumeToSceneBounds  (only in )

Set CSM Volume to scene bounds.

SetCSMVolumeViaCSMVolumeEntity <targetnameRedirectInput/string> (only in )

Set CSM Volume to CSM Volume Entity.

Disable <void>

Disable this entity.

Note:Only in Xengine work as expected. Counter-Strike: Global Offensive's implementation only disable blobby shadows and lighting in viewmodel, also cause freeze for some seconds.

Enable <void>

Enable this entity.

Note:Only in Xengine work as expected. Counter-Strike: Global Offensive's implementation only enable blobby shadows and lighting in viewmodel, also cause freeze for some seconds.

See also

• light_environment
• Shadow_control
• env_sun
• Skybox Basics
• Skybox lighting
• Advanced Lighting
• Effect flags (dynamic light effects)
• newLight_Dir
• newLight_Point
• newLight_Spot
• NewLights_settings
• New_Specular
• light_deferred
• light_deferred_global

External links

• ^[3] BlackMesa XenEngine: Part3 – CSM 2.0] (page from Black Mesa developer about their own CSM implementation)
• ^[4] BlackMesa XenEngine: Part2 – How a Frame is Rendered] (page from Black Mesa developer about new graphics features)
• ^[5] BlackMesa XenEngine: Part1 – Heavily Modified Source Engine] (page from Black Mesa developer about Black Mesa engine, better known as Xengine)

References

^[1]: https://learn.microsoft.com/en-us/windows/win32/dxtecharts/cascaded-shadow-maps ^[2]: https://github.com/celisej567/Fake-CSM-Source-2013 ^[3]: https://chetanjags.wordpress.com/2023/07/17/blackmesa-xenengine-part3-csm-2-0/ ^[4]: https://chetanjags.wordpress.com/2023/07/11/blackmesa-xenengine-part2-how-a-frame-is-rendered/ ^[5]: https://chetanjags.wordpress.com/2022/06/01/blackmesa-xenengine-part1-a-heavily-modified-source-engine/