What a run changes

What it reads§

The load order is every content= line in your openmw.cfg chain, in order. Each file is looked up in the data= folders, then data-local, and as in OpenMW a later folder wins: when two hold a file of the same name, the one OpenMW would load is the one read. Then it skips:

• files that are not .esp, .esm, .omwaddon or .omwgame, such as .omwscripts;
• its own plugin: any file named S3LightFixes with one of those extensions, in any case;
• plugins matching excluded_plugins, which by default lists

seven plugins it cannot read;

• plugins that fail to load. Each prints a warning on standard error and the run goes on without

it.

From each plugin it reads only two kinds of record, lights (LIGH) and cells (CELL), and it reads the plugins in parallel.

Which version of a light wins§

When several plugins have a light with the same id, the last one in the load order wins, as it does in OpenMW. S3LightFixes starts from that version, and ids are compared without regard to case. A light whose id matches excluded_ids is skipped in every plugin, so no version of it is written and OpenMW uses the one it would have used anyway.

Every other light goes into the plugin, changed or not. With the default settings almost all of them change.

What happens to a light§

In this order:

1. Negative lights go dark. A light with the NEGATIVE flag loses the flag and gets radius 0

and color black, and nothing else below applies to it. disable_negative_lights = false keeps them as they are.

1. Flicker stops. FLICKER and FLICKER_SLOW are removed. disable_flickering = false keeps

them.

1. Pulse stays, unless disable_pulse = true, which removes PULSE and PULSE_SLOW.
2. Standard or colored. The light's color is converted to hue, saturation and value. A hue from

14° to 64°, inclusive, is the orange of fire and candles: a standard light. Anything else is a colored light, and that includes white and grey, whose hue is 0°.

1. Color. Hue, saturation and value are each multiplied by their multiplier for the light's

kind, and converted back to red, green and blue.

1. Radius is multiplied by the kind's radius multiplier and rounded down.
2. Duration is multiplied by duration_mult and rounded toward zero. A duration of -1 means

the light never burns out, and stays -1.

The multipliers, with their defaults:

So a standard light turns a little redder, less saturated and darker, and reaches a fifth further. The torch from Morrowind.esm has the color [245, 140, 40]: hue 29.3°, saturation 0.84, value 0.96. After the multipliers that is hue 18.1°, saturation 0.67, value 0.55:

LIGH "torch" from "Morrowind.esm": color [245, 140, 40, 0] -> [140, 74, 46, 0], radius 256 -> 307, duration 210 -> 525, flags LightFlags(DYNAMIC | CAN_CARRY | FIRE | OFF_BY_DEFAULT | FLICKER_SLOW) -> LightFlags(DYNAMIC | CAN_CARRY | FIRE | OFF_BY_DEFAULT)

A blue lantern, hue 210°, is a colored light: its hue stays, and it loses a little saturation and brightness:

LIGH "light_de_lantern_02" from "Morrowind.esm": color [0, 128, 255, 0] -> [18, 98, 178, 0], radius 256 -> 281, duration 150 -> 375, flags LightFlags(DYNAMIC | CAN_CARRY | FIRE | FLICKER_SLOW) -> LightFlags(DYNAMIC | CAN_CARRY | FIRE)

Duration is multiplied for every light that is not infinite. The help calls it the duration of carried lights, the time a light burns once picked up; for the others the value is not used.

When a light matches a light override, the override's values replace or refine steps 5 to 7 and may replace the flags. Steps 1 to 3 still come first, so an override cannot bring back a negative light.

What happens to a cell§

Cells are only written when you ask for it. An interior cell with ambient data is written when:

• --classic or disable_interior_sun = true is set: its sunlight color becomes black. This is

only for vtastek's shaders for OpenMW 0.47, which --classic is named after;

• or its id matches an ambient override: the override's ambient,

sunlight and fog colors and fog density replace the cell's.

The copy is the version from the last plugin that has the cell, without its objects and without its water height, so loading it changes the cell's lighting and nothing else. Exterior cells are never written.

The plugin§

S3LightFixes.omwaddon is an ordinary TES3 plugin: an ESP header, version 1.3, author S3, description Plugin generated by s3-lightfixes. Its masters are the plugins that supplied at least one of its records, in load order, with their sizes. For Morrowind with both expansions it holds 676 lights and has three masters.

If no plugin supplies a record, say because every light is excluded, nothing is written: the run stops with a message that the plugin would be empty, and exit code 2.

The log§

Each run prints a summary and one line per changed record, and writes the same text to lightconfig.log next to lightconfig.toml, replacing the last run's. A dry run prints it with Dry run: no files written in front, and writes no log.

# S3LightFixes 0.5.0
# config: /home/you/.config/openmw/openmw.cfg
# output: /home/you/.local/share/openmw/data/S3LightFixes.omwaddon
# content files: 3
# loaded plugins: 3
# masters: 3
# changed cells: 1
# changed lights: 676
CELL "balmora, caius cosades' house" from "Morrowind.esm": ambient [75, 65, 65, 0] -> [64, 48, 32, 0], fog_density 0.75 -> 0.5

A record line names the record type, its id as the plugin spells it, the plugin it came from, and each value that changed: color and the cell colors as [red, green, blue, 0], radius, duration, flags, and fog_density. A light that did not change is in the plugin but not in the log.