September 30, 2012

Effectinfo Scripting Reference

EffectInfo is built-in scripting language to describe particle effects in DarkPlaces, it’s pretty simple and contains basic scripting functions.

Each effect can have several emitters which is defined in effectinfo.txt or maps/mapname_effectinfo.txt


General syntax

 // emitter 1
 parm value
 parm2 value

 // emitter 2
 parm value
 parm2 value

 // emitter for another effect
 parm value
 parm2 value

Console variables

r_drawparticles : toggle drawing of all particles

r_drawparticles_drawdistance : set a maximal distance to draw particles at

cl_particles_size : this will scale a size of all particles

cl_particles_quality : multiplier of particles count spawned by emitters, better quality = more particles (1 – min, 4 – max. quality)

cl_particles_reloadeffects : reloads effectinfo.txt while in the game; that eliminates a need to quit and restart DP to see updated effects

Particle parameters

effect <name>

Defines a new emitter with effectname is belongs to, all parms after that will be applied to that emitter.

count <count>

How many particles to spawn at this emitter, this setting is affected by cl_particles_quality cvar

countabsolute <count>

Defines a count of particles spawned regardless of cl_particles_quality setting

Total particles count = countabsolute + count * cl_particles_quality

type <type>

Sets a generic particle type, affect appearance, blending, physics.

List of particle types:

alphastatic : alpha-blended billboard
static : additive-blended billboard
spark : additive blended, stretched (based on velocity)
beam : a beam particle, drawn from origin to origin + velocity
rain : a rain particle, alpha-blended spart that will cause splash effect on impact
raindecal: oriented rain decal, additive-blended
snow: alpha blended, velocity jitters in realtime
bubble: alpha-blended
blood: inverse-modulated, leaves decal
smoke: alpha-blended billboard
decal: makes a decal on nearest surface
entityparticle: alpha-blended, this particle gets removed after being drawn (used on EF_BRIGHTFIELD)

blend <blendtype>

Generic blend is set by type, but with this parm it cound be changed after type is defined.

List of blend types:

alpha : alpha blended
add: additive blended
invmod: inverse modulation (used on blood and blood decals)

orientation <orientationtype>

Same as for blend, generic orientation is set by type, could be altered by this parm.

List of orientation types:

billboard : always turned to viewer
oriented : ignores viewwer, turned to velocity
beam : facing viewer on 2 axises, stretched from origin to origin + velocity
spark : facing viewer on 2 axises, stretched (based on velocity)

color <min_color> <max_color>

Sets a color for particles. On each particle spawn, it’s color is linearly randomized betwen two given colors. Color should be defined as HEX 0xRRGGBB, like 0xFFFFFF is white, and 0xFF0000 is red.

tex <min_index> <max_index>

Sets a index of particle from particlefont. Indexes are counted from left to right, from up to down, last index is 63, first is 0. Randomized linearly on each particle spawn.

size <min_size> <max_size>

Size of particle in game units, typical value is 4, randomized.

sizeincrease <rate>

This will make particle grow or diminish over time. <rate> is to how much utits to add or subtract per second. Note that while diminishing particle, engine will not check if particle will go to negative size, it will just invert it.

alpha <min_alpha> <max_alpha> <fade_rate>

Opacity of particles, 256 is opaque, 0 is transparent. Randomized. Could be more that 256 (to simulate fade delay). Fade rate is how huch alpha to throw away per second, once particle gets alpha 0 (full transparence), it gets removed.

time <min_time> <max_time>

Particle time-to-live in seconds, randomized.

gravity <value>

Particle gravity modifier, 1 is full gravity, 0.5 is half etc., negative values are supported (particle go up).

bounce <value>

Particle bounce-of-walls factor, 1 – bounce with full speed, 0.5 bounce with half speed. A value of -1 means particle will be removed on impact. Not that particle physics considered slow and spawning lots of bouncing particles is not recommended.

airfriction <value>

Particle friction while moving in air, good option for smoke emitters. A value of 0 means no friction, negative values will do acceleration.

liquidfriction <value>

Particle friction while moving in liquids.

originoffset <x> <y> <z>

Offset particle spawning origin by this values. Coordspace are world, x – forward, y – right, z – up.

velocityoffset <x> <y> <z>

Add this amount of constant velocity to particle on spawn.

originjitter <x> <y> <z>

Like originoffset but each axis is jittered between -value/+value. Hence it is defining spherical shape of particle random spawning.

velocityjitter <x> <y> <z>

Same as originjitter but for velocity.

velocitymultiplier <x>

Multiply particle starting velocity (one that set by QC or engine, whatever calls effect) by this value. Useful with trails. Negative values are supported.


Sets underwater flag for particles. Particles that are underwater will be removed in air. Useful for water bubbles.


Sets notunderwater flag for particles. Particles that are notunderwater will be removed in liquid. Useful for fire particles.

trailspacing <x>

This parm is only useful when effect is spawned as trail, defines a game units gap between effect invocations.

stretchfactor <x>

A custom stretch factor that is used on sparks.

rotate <startangle_min> <startangle_max> <spin_min> <spin_max>

Used to rotate particle, first 2 parms is start angle, other two are spin velocity.

Particles leaving decals

Particles can leave decals once hit something. For this behavior a special set of parms should be used. This section is unfinished, futher explanation is required.

staincolor <min_color> <max_color>

A randomized color for decal particle.

stainalpha <min_alpha> <max_alpha>

A randomized alpha.

stainsize <min_size> <max_size>

A randomized size.

staintex <min_index> <max_index>

A randomized index into particlefont.


Disables decal spawning and returns all parms to it’s default values.

Dynamic lights

Dynamic realtime lights could be placed in particle effects (useful for explosions) with this range of parms. This parms applied just like standart ones.

lightradius <radius>

Radius of light in game units. Typical value is 200.

lightradiusfade <rate>

Radius fade rate, how many units to add/subtract per second. Once light reaches radius of 0 it gets removed.

lighttime <time>

If radius fading not set, this parm can be used to define light life time.

lightcolor <red> <green> <blue>

A RGB-normalized light color, 1 1 1 is white, 0 0 1 is blue. Can exceed 1 (overbright light).

lightshadow <value>

Cast shadows from light, value is 0 or 1.

lightcubemapnum <value>

Sets a numbered cubefilter for light, cubemap texture is cubemaps/<value>

Engine effect names

Heres a list of effect names used by engine.


Known bugs

maps/mapname_effectinfo.txt does not add effects at the moment, but replaces the whole effects info
The Engine now appends mapname_effectinfo.txt to effectinfo.txt. In other words you can create additional effects for your map without changing effectinfo.txt