OpenMW integration

What a compile writes#

morrobroom compile turns the saved map into:

The output directory is --output-dir, and by default the folder the map is in. The TrenchBroom Map-to-Engine profile points both at build/<map name>/, which keeps each map’s files together, keeps maps from overwriting each other’s meshes, and keeps generated content out of your real data directories. That folder is a complete data directory: OpenMW loads it with --data.

To find textures, Morrobroom reads your OpenMW configuration the way OpenMW does, starting from openmw-config’s root discovery and falling back to the user’s config. Pass --config with a config file or directory to compile against a different loadout.

Compiling into an existing plugin#

If the plugin already exists, Morrobroom updates it: the records this map made last time, including its cell, are replaced, and everything else in the plugin stays. Dialogue, scripts and other records you add in OpenCS survive a recompile. Changes made in OpenCS to the compiled cell or to the records the map made do not: those belong to the map.

The Map-to-Engine profile deletes the plugin before compiling, so every test run starts clean. Turn that step off in Run → Compile Map if you are building on top of a plugin.

Baked lighting#

Lighting is on by default. Morrobroom creates a second UV set for static geometry, bakes ambient light plus the map’s point lights and their shadows, and writes the result as a BC7 DDS lightmap attached through Morrowind’s existing dark map slot.

OpenMW loads it without an engine patch. It is a static bake, not global illumination: actors and anything else that moves are still lit by OpenMW’s ordinary lights, which the compiled light records provide. Turn the bake off with --no-lightmaps while iterating on geometry, or when a map does not need it. A map without visible brush faces, such as one built only from placed records, has nothing to bake onto, so the compiler says so and skips the bake.

An entity with its own Nif_Texture_DarkMap keeps it, instead of the lightmap. See NIF authoring.

Scale#

Quake-style maps and Morrowind assets do not share a scale: Quake maps come out about half the size of Morrowind’s. The compiler scales by 2.0 by default, for Morrowind-sized content, and the Map-to-Engine profile passes the same. Use --scale for maps authored at another scale, and keep the same value for fgd --scale, so catalog entities are the size they will be in game, and for nif2map --scale, so imported meshes are too.

Plugin types#

The plugin can be .esp, .esm, .omwaddon or .omwgame; the extension decides. For TrenchBroom iteration, an .omwaddon in the map’s build directory is the least surprising choice.

The entity catalog for your load order#

Morrowind.fgd is the compact schema for editing. To place your installed game’s and mods’ records from TrenchBroom’s entity browser, generate a catalog from your OpenMW configuration:

morrobroom fgd --config /path/to/openmw.cfg

It writes MorrowindObjects.fgd into TrenchBroom’s per-user Morrowind game directory from Start here, beside Morrowind.fgd and GameConfig.cfg, never into Data Files/. It refuses when Morrobroom’s game files are not installed there yet. Use --output <path> for TrenchBroom’s portable mode, or anywhere else.

To catalog only some record types, list their TES3 tags:

morrobroom fgd --config /path/to/openmw.cfg --types "stat;door;ligh;acti"

Regenerate after changing your load order, then reload the game configuration in TrenchBroom.

Each record shows as a box the size of its model. Placing one compiles to a reference to that record; Entities has the details.