Files
gig-line/Art/blender/site/export_site_fbx.py
T
zwitschi 286d9f6479 refactor(tools): one FBX export preset instead of six copies
The bpy.ops.export_scene.fbx argument block was duplicated in six scripts (hero,
block frontage, north buildings, site, scale test, MPFB character) and all six
carried mesh_smooth_type="OFF", which drops smoothing groups and made every
Unreal import warn and every round part faceted.

Tools/fbx_export_preset.py now owns the presets:
- preset_kwargs(preset, selection, **overrides) is bpy-free and unit-tested;
- export_static()/export_character() are thin wrappers that import bpy lazily;
- ue_metric_v1 and ue_character_v1 keep the recorded scale contract
  (FBX_SCALE_NONE, apply_unit_scale, -Y forward / Z up) and use FACE smoothing.

Callers switched: hero_facade_build, export_block_frontage, export_north_buildings,
scale_test_export, mpfb_character_export, Art/blender/site/export_site_fbx.

Verified by re-exporting every asset through the preset and re-importing all of
them: 0 smoothing warnings on site, frontage and north buildings; packaging and
-qaselftest all PASS (walk, transect 0 holes, wall probe 0/35, facade probe 0/9).
49 tool tests pass (9 new for the preset contract).
2026-11-08 18:00:59 +01:00

84 lines
3.3 KiB
Python

"""Export the site meshes from the assembled site .blend, one FBX per object.
blender -b --factory-startup Art/blender/site/site-2026-11-06.blend \
--python Art/blender/site/export_site_fbx.py -- --out /tmp/gigline/site
Why one file per object: terrain, road, sidewalks and kerbs want different
collision settings in Unreal, and a single combined mesh cannot carry that.
Uses the same named export preset `ue_metric_v1` as the scale test, so the metre
to centimetre mapping is identical to the one already verified.
"""
import argparse
import os
import sys
import bpy
sys.path.insert(0, os.path.join(os.path.join(os.path.dirname(__file__), "..", "..", ".."), "Tools"))
import fbx_export_preset as fbx_preset # noqa: E402
MESHES = ("Terrain_DEM", "Road_Hollywood", "Sidewalk_South", "Sidewalk_North",
"Kerb_South", "Kerb_North", "Crossing_Markings")
def main():
argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []
ap = argparse.ArgumentParser()
ap.add_argument("--out", default="/tmp/gigline/site")
args = ap.parse_args(argv)
os.makedirs(args.out, exist_ok=True)
print(f"[site] scene objects: {len(bpy.data.objects)}")
found = []
for name in MESHES:
obj = bpy.data.objects.get(name)
if obj is None or obj.type != "MESH":
print(f"[site] MISSING {name}")
continue
found.append(name)
for name in found:
# export only the object under test: select it, export, deselect
bpy.ops.object.select_all(action="DESELECT")
obj = bpy.data.objects[name]
obj.select_set(True)
# Sidewalks were generated with their north/south offsets inverted relative
# to the road and kerbs: in Unreal the north sidewalk landed at the south
# kerb. Mirror this one object across Y so the export matches the source
# frame instead of rotating the actor in the map.
mirrored = False # the south sidewalk is correct in the .blend; see street_mesh
if mirrored:
obj.scale.y *= -1.0
bpy.context.view_layer.objects.active = obj
bpy.ops.object.transform_apply(location=False, rotation=False, scale=True)
# Object mode has no mesh context; flip winding through the mesh data.
me = obj.data
for poly in me.polygons:
verts = list(poly.vertices)
verts.reverse()
poly.vertices = verts
me.update()
_ = bpy.context.view_layer
bpy.context.view_layer.objects.active = obj
path = os.path.join(args.out, name + ".fbx")
fbx_preset.export_static(path, selection=True)
if mirrored:
# The flip is an export correction, not a change to the source: undo it.
obj.scale.y *= -1.0
bpy.ops.object.transform_apply(location=False, rotation=False, scale=True)
for poly in obj.data.polygons:
verts = list(poly.vertices)
verts.reverse()
poly.vertices = verts
obj.data.update()
zs = [(obj.matrix_world @ v.co).z for v in obj.data.vertices]
print(f"[site] {name:18} verts {len(obj.data.vertices):6} z {min(zs):+.2f}..{max(zs):+.2f} m "
f"-> {path}")
print(f"[site] exported {len(found)} of {len(MESHES)} meshes")
main()