Lighting
Revision as of 03:58, 8 August 2011 by MrFourVideoCards (talk | contribs) (→Static light receivers)
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Contents
Guides
- Adding Light - A beginners tutorial on how to set up a basic light entity.
- Intermediate Lighting - A tutorial dealing with all the light sources in more detail.
- Advanced Lighting
- Constant-Linear-Quadratic Falloff - An easy-to-read explanation of the old C-L-Q light attenuation system.
- HDR - High Dynamic Range Lighting.
Types
Static light sources

- light
- A static, omni-directional point light source. (e.g. a naked light bulb or flame.)
- light_spot
- A static, uni-directional point light source. (e.g. a torch or flashlight) The conical beam angle cannot exceed 90°.
- light_environment
- Provides two linked light sources:
- A diffuse 'ambient' light (representing reflected light from clouds and the atmosphere in general) that emits from all skybox surfaces
- A directional 'brightness' light (representing sunlight or moonlight) that is only cast in a single direction.
- Both are emitted from the toolsskybox material wherever it is used on a map. See also Skybox.
- env_particlelight
- Illuminates particles produced by env_smokestack. Particles are not affected by normal lighting. Use (no more than) two of these to make (only) env_smokestack particles appear to reflect ambient lighting.
- Glowing Textures
- Brush surfaces with a light-emitting material (as defined in
game_dir/lights.rad
) applied will cast volumetric light in a 180° cone.
Static light receivers
- Brushes
- This Hammer Face Edit Dialog tool 'Lightmap Scale' can be used to control how sharp or diffuse the lightmap of a brush surface will be - an effect most noticeable between areas of high contrast, e.g. shadows. Note that while adding extra light sources will not affect performance, decreasing lightmap scale (i.e. increasing resolution) will.
- prop_static
- Unlike other model entities, prop_static are lit statically: a lighting value is stored for every vertex, and the model's collision mesh (or, optionally, reference mesh) is used to calculate lightmap shadows.
- There are the following options:
disableshadows
- Do not cast lightmap shadowsdisablevertexlighting
- Only store a single lighting value for the entire modeldisableselfshadowing
- Prevents the entity from casting shadows on itselfignorenormals
- Ignores normals of vertex data to calculate lighting. This is extremely useful for foliage, and other thin types of vertex meshes.
Dynamic light sources


env_projectedtexture shines from a doorway.
- light_dynamic
- A simple, uni-directional dynamic light that can be moved, turned, and adjusted.
- point_spotlight
- A dynamic spotlight beam effect, with an optional dynamic light source where it hits a surface.
- npc_spotlight
- A spotlight NPC, similar to point_spotlight but with the capability of tracking targets.
- env_projectedtexture
- A dynamic light that lights with a texture rather than a solid colour, and which also 'subtracts' realistic dynamic shadows. Affects all surfaces that can accept lighting, and is used for the player flashlight in Episode Two.
Dynamic shadows



- shadow_control
- Point entity used to control Dynamic Shadow projections for the entire map, including maximum distance cast, direction cast, and sharpness/diffuseness.
- info_no_dynamic_shadow
- Point entity used to list Brush surfaces that should not receive Dynamic Shadows.
- prop_physics entities
- have a "shadowcastdist" keyvalue to override how far this object casts Dynamic Shadows.
- prop_dynamic entities
- have a "disableshadows" keyvalue, and "enableshadows" and "disableshadows" inputs to control Dynamic Shadows cast by them.
- NPC entities
- have the prop_dynamic shadow controls, plus a "disablereceiveshadows" To do: to prevent...?
Tyndall effects
Tyndall effects are caused by light scattering on suspended (colloid) particles in a transparent medium. Eg car headlights in fog.
- Halo (Glow Sprite) effects :
- env_sprite - entity used to create omni-directional glow or flare effects.
- env_lightglow - an asymmetrical glow (for areas of contrasting light).
- env_sun - adds a bright haloed spot to the Skybox to represent the position of the Sun or Moon.
- Lightbeam (Volumetric Light) effects :
- Brush texture :
models/effects/vol_light001
- Brush texture :
models/effects/vol_light002
- Model :
models/Effects/vol_light.mdl
- use with prop_static.
- Brush texture :
- See also Render Modes for sprites, particularly World Space Glow.
Common values
- Car Headlights
- Brightness
231 223 192
Note: Taken from L4D2 SDK
- City 17 day
- Brightness
237 218 143 800
- Ambience
190 201 220 100
- Ravenholm night
- Brightness
175 230 239 50
- Ambience
43 45 57 5
- Combine lamp
- Brightness
147 226 240 3000
- Ambience N/A
- Tungsten bulb
- Brightness
254 216 146
- Ambience N/A
- Fluorescent bulb
- Brightness
159 237 215
- Ambience N/A
For values to accompany the stock skybox materials, see Sky List.
Notes
- Naming a light makes it more expensive. Only name lights when you need to. Multiple lights sharing the same name are cheaper than lights with separate names.
- light_dynamic is especially expensive, and will not even show up on some systems
- The basic light entities do not come with a visible representation (e.g. a lightbulb). For that you need a prop. See HL2 light props for a list.
- The basic light entities do not come with a "glow" as you'd expect to see in a foggy or misty area. To provide this, either compile and run the map with HDR enabled, or add a point_spotlight (with dynamic lighting off unless needed) or env_lightglow entity.
- Maps will not be lit unless you run vrad (or equivalent). Vrad will not run properly and will not calculate realistic light bounces unless the level is free of leaks.
- Several textures provide their own light & can do so using
lights.rad
in a mod's directory or the one insourcesdk/bin
. - Moving brushed-based objects will not change the way they are lit. Their lighting will be calculated only according to their positions in Hammer. (e.g. a brush in a dark room will not become bright if it is brought into a bright room.)
Console commands
mat_fullbright <0-2>
0
is normal lighting.1
is 'full bright' lighting, where everything is 100% lit.2
has been introduced with the Orange Box and is 'lighting only'. It replaces all textures' images with a colourless monotone, allowing you to see exactly what is lit, where, and probably how.
See also
- HL2 light props
- Color theory (level design)
- Light entities - A list of light entities.
- Intermediate Lighting
- Advanced Lighting
- Window lighting - How to simulate refracted sunlight through openings.
External links
- Lighting Tutorial - Covers entities & variables with examples
- Quadratic/Linear/Constant in Lights