2.6 KiB
Sound: EFX
EFX
EFX is a system in OpenAL that delivers high quality sound reverberation. It is the successor to Creative's Environmental Audio Extensions.
Nuclide offers abstraction for new and old entities relying on digital signal processing.
Entities interacting with EFX
env_sound is most commonly used to change the environmental sound processing of a room/area.
In GoldSrc, it'll specify which enumeration of DSP preset to use for audio playback, in Nuclide however we just map it to a definitions file in the filesystem. See EFX files below.
EFX defintion files
Entities that specify a EFX type, usually want to load one from a file.
Here's an example one, efx/city.efx:
density "1.000000"
diffusion "0.500000"
gain "0.316200"
gain_hf "0.398100"
gain_lf "1.000000"
decay_time "1.490000"
decay_hf_ratio "0.670000"
decay_lf_ratio "1.000000"
reflections_gain "0.073000"
reflections_delay "0.007000"
reflections_pan "0 0 0"
late_reverb_gain "0.142700"
late_reverb_delay "0.011000"
late_reverb_pan "0 0 0"
echo_time "0.250000"
echo_depth "0.000000"
modulation_time "0.250000"
modulation_depth "0.000000"
air_absorbtion_hf "0.994300"
hf_reference "5000.000000"
lf_reference "250.000000"
room_rolloff_factor "0.000000"
decay_limit "1"
Most of the parameters are self explanatory.
Console Variables
With the cvar s_al_debug set to 1 you'll get an overlay of information about which EFX file is currently being used, as well as what every single parameter is set to.
You can refresh EFX definitions with a map restart.
Legacy translation table
This section describes behaviour specific to converting entities from Half-Life based levels into the Nuclide environment.
Here you can see which efx file is responsible for handling a legacy env_sound room-type.
| roomtype ID | EFX file |
|---|---|
| 0 | efx/default.efx |
| 1 | efx/gs_generic.efx |
| 2 | efx/gs_metal_s.efx |
| 3 | efx/gs_metal_m.efx |
| 4 | efx/gs_metal_l.efx |
| 5 | efx/gs_tunnel_s.efx |
| 6 | efx/gs_tunnel_m.efx |
| 7 | efx/gs_tunnel_l.efx |
| 8 | efx/gs_chamber_s.efx |
| 9 | efx/gs_chamber_m.efx |
| 10 | efx/gs_chamber_l.efx |
| 11 | efx/gs_bright_s.efx |
| 12 | efx/gs_bright_m.efx |
| 13 | efx/gs_bright_l.efx |
| 14 | efx/gs_water1.efx |
| 15 | efx/gs_water2.efx |
| 16 | efx/gs_water3.efx |
| 17 | efx/gs_concrete_s.efx |
| 18 | efx/gs_concrete_m.efx |
| 19 | efx/gs_concrete_l.efx |
| 20 | efx/gs_big1.efx |
| 21 | efx/gs_big2.efx |
| 22 | efx/gs_big3.efx |
| 23 | efx/gs_cavern_s.efx |
| 24 | efx/gs_cavern_m.efx |
| 25 | efx/gs_cavern_l.efx |
| 26 | efx/gs_weirdo1.efx |
| 27 | efx/gs_weirdo2.efx |
| 28 | efx/gs_weirdo3.efx |