gig-line/Tools/ue_build_demo_map.py

# Build /Game/Hollywood/DemoMap: the walkable demo level.
#
#   <engine>/Engine/Binaries/Linux/UnrealEditor-Cmd <uproject> -run=pythonscript \
#     -script=<repo>/Tools/ue_build_demo_map.py -nullrhi -unattended -nopause -stdout
#
# Content this map expects (built by earlier steps):
#   /Game/Hollywood/ElCapitan/SM_HeroFacade   Tools/ue_hero_facade_import.py
#   /Game/Hollywood/Site/...                  Tools/ue_import_site.py
#
# Map conventions, from Geo/manifests/local-origin.md:
#   X east, Y south, Z up, centimetres, origin at Hollywood x Highland.
#   The player starts on the north sidewalk opposite the hero frontage, looking
#   south at it, which is the view the reference photographs were taken from.
#
# Every actor is (re)created by label, so rerunning the script rebuilds the map
# deterministically instead of stacking duplicates.

import os

import unreal

MAP = "/Game/Hollywood/DemoMap"
RESULT = "/tmp/gigline/demo-map.txt"
lines = []


# EditorLevelLibrary.load_level/new_level are deprecated no-ops in -nullrhi
# commandlets (they return without switching worlds, so staged actors land in
# whatever world is current and get saved over the wrong map). The
# LevelEditorSubsystem actually switches.
LES = unreal.get_editor_subsystem(unreal.LevelEditorSubsystem)


def switch_level(path):
    return LES.load_level(path)

def log(msg):
    lines.append(str(msg))
    unreal.log(str(msg))


def spawn(cls, loc, label, rot=None):
    actor = unreal.EditorLevelLibrary.spawn_actor_from_class(cls, loc)
    if actor is None:
        log(f"spawn {cls} failed")
        return None
    if rot is not None:
        actor.set_actor_rotation(rot, False)
    actor.set_actor_label(label)
    return actor


def clear(prefixes=()):
    removed = 0
    for actor in unreal.EditorLevelLibrary.get_all_level_actors():
        label = actor.get_actor_label()
        if label.startswith(prefixes):
            unreal.EditorLevelLibrary.destroy_actor(actor)
            removed += 1
    return removed


def build():
    # --- level ------------------------------------------------------------
    if unreal.EditorAssetLibrary.does_asset_exist(MAP):
        if not switch_level(MAP):
            log(f"could not load {MAP}")
            return
    else:
        if not switch_level(MAP):
            log(f"could not create {MAP}")
            return

    removed = clear(("Demo_", "PlayerStart", "Hero_Facade"))
    log(f"cleared {removed} previous demo actors")

    # --- lighting ---------------------------------------------------------
    spawn(unreal.DirectionalLight, unreal.Vector(0, 0, 2000), "Demo_Sun",
          unreal.Rotator(pitch=-35.0, yaw=200.0, roll=0.0))
    spawn(unreal.SkyLight, unreal.Vector(0, 0, 2000), "Demo_SkyLight")
    spawn(unreal.SkyAtmosphere, unreal.Vector(0, 0, 0), "Demo_Sky")
    log("staged: sun, sky light, sky atmosphere")

    # --- hero facade on the measured building line ------------------------
    hero = unreal.EditorAssetLibrary.load_asset("/Game/Hollywood/ElCapitan/SM_HeroFacade")
    if hero:
        actor = spawn(unreal.StaticMeshActor, unreal.Vector(-10722.5, -1443.0, 0.0), "Hero_Facade")
        if actor:
            actor.static_mesh_component.set_static_mesh(hero)
            actor.static_mesh_component.set_mobility(unreal.ComponentMobility.STATIC)
            log("staged: Hero_Facade at the building line")
    else:
        log("MISSING: SM_HeroFacade — run Tools/ue_hero_facade_import.py")

    # --- site meshes, if they have been imported --------------------------
    imported = 0
    for name in ("Terrain_DEM", "Road_Hollywood", "Sidewalk_South", "Sidewalk_North",
                 "Kerb_South", "Kerb_North", "Crossing_Markings"):
        mesh = unreal.EditorAssetLibrary.load_asset(f"/Game/Hollywood/Site/{name}")
        if mesh is None:
            continue
        actor = spawn(unreal.StaticMeshActor, unreal.Vector(0, 0, 0), f"Demo_{name}")
        if actor:
            actor.static_mesh_component.set_static_mesh(mesh)
            actor.static_mesh_component.set_mobility(unreal.ComponentMobility.STATIC)
            imported += 1
    log(f"staged {imported} site meshes from /Game/Hollywood/Site")

    # --- player start: north sidewalk, facing the hero frontage -------------
    # Signs were measured from the imported meshes rather than assumed: the FBX
    # preset flips north, so in Unreal the road spans Y -1382..+1047, the NORTH
    # sidewalk is at Y -1912..-1053 and the SOUTH sidewalk at Y +718..+1447. The
    # facade stands at Y -1450. Stand on the north sidewalk and look north (-Y).
    spawn(unreal.PlayerStart, unreal.Vector(-10722.5, -3500.0, 120.0), "Demo_PlayerStart",
          unreal.Rotator(pitch=0.0, yaw=0.0, roll=0.0))
    log("staged: Demo_PlayerStart on the north sidewalk facing south")

    # A lockable LFS .umap checks out read-only, which makes save_map silently
    # return False — chmod u+w first or the staged actors never persist.
    umap = os.path.join(unreal.Paths.project_dir(), MAP.replace("/Game/", "Content/") + ".umap")
    if os.path.exists(umap) and not os.access(umap, os.W_OK):
        os.chmod(umap, 0o644)
        log(f"map writable: chmod u+w {umap}")
    saved = unreal.EditorLoadingAndSavingUtils.save_map(
        unreal.EditorLevelLibrary.get_editor_world(), MAP)
    log(f"save_map {MAP}: {saved}")


try:
    build()
except Exception as exc:  # noqa: BLE001
    import traceback
    log(f"FAILED: {type(exc).__name__}: {exc}")
    log(traceback.format_exc())

with open(RESULT, "w") as f:
    f.write("\n".join(lines) + "\n")