699 lines
28 KiB
Python
699 lines
28 KiB
Python
"""Blender 内运行：FBX/GLB/glTF 减面到指定三角面数 + UV 重展（锐边 seam 或 Smart UV Project）。
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调用：blender -b --factory-startup --python bl_decimate.py -- <src> <out.fbx> <target_tris> [seam|smart]
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"""
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import os
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import sys
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sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
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SUPPORTED_MODEL_EXTENSIONS = (".fbx", ".glb", ".gltf")
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FBX_YUP_EXPORT_VERSION = 2
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def model_format(path):
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"""Return the Blender importer key for a supported model path."""
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ext = os.path.splitext(path)[1].lower()
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if ext == ".fbx":
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return "fbx"
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if ext in (".glb", ".gltf"):
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return "gltf"
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raise ValueError(
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"unsupported model format %r (supported: %s)"
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% (ext or "<none>", ", ".join(SUPPORTED_MODEL_EXTENSIONS)))
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def import_model_objects(path):
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"""Import FBX/GLB/glTF and return only objects created by the importer."""
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import bpy
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before = set(bpy.data.objects)
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fmt = model_format(path)
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if fmt == "fbx":
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bpy.ops.import_scene.fbx(filepath=path)
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else:
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bpy.ops.import_scene.gltf(filepath=path)
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return [obj for obj in bpy.data.objects if obj not in before]
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def restore_source_yup(obj):
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"""Blender Z-up 顶点还原为混元/glTF Y-up（-90°X）。须在 transform_apply 之后调用。"""
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import math
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import bpy
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bpy.ops.object.select_all(action='DESELECT')
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obj.select_set(True)
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bpy.context.view_layer.objects.active = obj
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obj.rotation_mode = "XYZ"
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obj.rotation_euler = (-math.pi / 2.0, 0.0, 0.0)
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bpy.ops.object.transform_apply(location=False, rotation=True, scale=False)
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def snap_origin_bottom_center(obj):
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"""原点放到底面中点：X/Z 居中，Y = 最低点。须已是 Y-up 且 transform 已 apply。"""
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from mathutils import Vector
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verts = obj.data.vertices
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if not verts:
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return
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xs = [v.co.x for v in verts]
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ys = [v.co.y for v in verts]
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zs = [v.co.z for v in verts]
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origin = Vector((
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(min(xs) + max(xs)) * 0.5,
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min(ys),
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(min(zs) + max(zs)) * 0.5,
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))
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for v in verts:
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v.co -= origin
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obj.data.update()
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obj.location = (0.0, 0.0, 0.0)
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def prepare_game_export(obj, restore_axis=None):
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"""最终游戏 FBX：Y-up，原点在底面中点。
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restore_axis: True 强制 -90°X；False 跳过；None 则导入后物体仍带约 +90°X 才还原。
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烘焙结束时顶点已是 Z-up、旋转已 apply，必须传 True。
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导出后保证 Y-up、原点底面中点；项目目标为解剖正面 +Z，须独立验收。
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解剖正面沿用输入。axis_forward='-Z' 是坐标转换设置，不代表人物脸部朝 -Z。
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"""
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import math
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import bpy
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bpy.ops.object.select_all(action='DESELECT')
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obj.select_set(True)
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bpy.context.view_layer.objects.active = obj
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if restore_axis is None:
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obj.rotation_mode = "XYZ"
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restore_axis = abs(obj.rotation_euler.x) > math.radians(45.0)
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bpy.ops.object.transform_apply(location=True, rotation=True, scale=True)
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if restore_axis:
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restore_source_yup(obj)
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snap_origin_bottom_center(obj)
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def export_fbx_source_yup(filepath):
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"""Export prepared Y-up geometry as an actual Y-up FBX scene.
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prepare_game_export stores Y-up vertices inside Blender's Z-up workspace.
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Passing those straight to the FBX exporter adds a -90 X object rotation,
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so consumers applying the complete FBX transform see a horizontal model.
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Restore Blender Z-up on temporary copies, then bake the export conversion.
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Leave source meshes, UVs, transforms and selection unchanged for callers.
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"""
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import math
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import bpy
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from mathutils import Matrix
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selected = list(bpy.context.selected_objects)
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active = bpy.context.view_layer.objects.active
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meshes = [obj for obj in selected if obj.type == "MESH"]
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if not meshes:
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raise ValueError("Select at least one prepared Y-up mesh for FBX export")
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copies = []
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source_names = [(source, source.name) for source in meshes]
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try:
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bpy.ops.object.select_all(action="DESELECT")
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for source, source_name in source_names:
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duplicate = source.copy()
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duplicate.data = source.data.copy()
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copies.append(duplicate)
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bpy.context.scene.collection.objects.link(duplicate)
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source.name = source_name + "__fbx_export_source"
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duplicate.name = source_name
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duplicate.parent = None
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duplicate.matrix_world = Matrix.Rotation(math.pi / 2, 4, "X") @ source.matrix_world
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duplicate.select_set(True)
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bpy.context.view_layer.objects.active = copies[0]
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bpy.ops.object.transform_apply(location=True, rotation=True, scale=True)
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bpy.ops.export_scene.fbx(
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filepath=filepath,
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use_selection=True,
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object_types={"MESH"},
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axis_forward="-Z",
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axis_up="Y",
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bake_space_transform=True,
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apply_unit_scale=True,
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apply_scale_options="FBX_SCALE_ALL",
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bake_anim=False,
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path_mode="STRIP",
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embed_textures=False,
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)
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return validate_fbx_yup_scene(filepath)
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finally:
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for duplicate in copies:
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mesh = duplicate.data
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bpy.data.objects.remove(duplicate, do_unlink=True)
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if mesh.users == 0:
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bpy.data.meshes.remove(mesh)
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for obj in selected:
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obj.select_set(True)
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for source, source_name in source_names:
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source.name = source_name
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bpy.context.view_layer.objects.active = active
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def validate_fbx_yup_scene(filepath):
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"""Reject the old extra node rotation even when raw vertices look Y-up."""
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from io_scene_fbx import parse_fbx
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root, _ = parse_fbx.parse(str(filepath))
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def properties(element):
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block = next(e for e in element.elems if e.id == b"Properties70")
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return {p.props[0].decode(): list(p.props[4:]) for p in block.elems}
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settings = properties(next(e for e in root.elems if e.id == b"GlobalSettings"))
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if settings.get("UpAxis") != [1] or settings.get("UpAxisSign") != [1]:
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raise ValueError("Exported FBX scene is not +Y-up")
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objects = next(e for e in root.elems if e.id == b"Objects")
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for model in (e for e in objects.elems if e.id == b"Model"):
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values = properties(model)
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if any(abs(v) > 1e-5 for v in values.get("Lcl Rotation", [0, 0, 0])):
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raise ValueError("Exported FBX retains an unbaked node rotation")
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if any(abs(v - 1) > 1e-5 for v in values.get("Lcl Scaling", [1, 1, 1])):
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raise ValueError("Exported FBX retains an unbaked node scale")
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return {"exportVersion": FBX_YUP_EXPORT_VERSION, "sceneUp": "+Y",
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"nodeRotationBaked": True, "nodeScaleBaked": True,
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"unitScaleFactor": settings.get("UnitScaleFactor", [1])[0]}
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TOLERANCE = 0.03 # 面数相对误差容忍
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MAX_RETRY = 2 # ratio 修正轮数上限
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def decimate_ratio(target, cur):
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"""Decimate collapse ratio；cur <= target 或非法时返回 1.0（不减面）。"""
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if cur <= 0 or cur <= target:
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return 1.0
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return target / float(cur)
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def within_tolerance(target, actual, tol=TOLERANCE):
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"""减面结果是否落在目标 ±tol 内。"""
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if target <= 0:
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return False
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return abs(actual - target) <= target * tol
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UV_FLIP_TOL = 0.02 # 质量门：UV 翻转面占比超此值回退 smart_project
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UV_OVERLAP_TOL = 0.08 # 质量门：UV 重叠面占比阈值（手工 UV 同口径约 5%，灾难性失败 >20%）
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UV_MAX_ISLAND_FRAC = 0.25 # 最大单岛 UV 面积占比超此值判不合格（挡光滑面巨型畸变岛）
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def uv_gate_ok(flipped, overlap, overlap_tol=UV_OVERLAP_TOL,
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max_island_frac=0.0, island_frac_tol=UV_MAX_ISLAND_FRAC):
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"""UV 质量门：翻转 / 重叠 / 最大单岛占比。overlap/max_island_frac 为 None 按 0。"""
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return (flipped <= UV_FLIP_TOL
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and (overlap or 0.0) <= overlap_tol
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and (max_island_frac or 0.0) <= island_frac_tol)
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def uvpm_mode_label(base, applied):
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"""UV 模式标注：UVPackmaster 排布生效时加 +uvpm 后缀。"""
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return base + "+uvpm" if applied else base
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def pick_best_candidate(candidates, overlap_tol=UV_OVERLAP_TOL):
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"""从候选 UV 指标 dict 列表选过质量门且岛数最少者；无过门候选返回 None。"""
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passing = [c for c in candidates
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if uv_gate_ok(c["flipped"], c["overlap"], overlap_tol,
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c.get("max_island_frac", 0.0))]
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if not passing:
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return None
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return min(passing, key=lambda c: c["islands"])
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def island_labels(n_faces, adjacent_pairs):
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"""union-find：返回每个面所属岛根标签列表。"""
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parent = list(range(n_faces))
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def find(i):
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while parent[i] != i:
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parent[i] = parent[parent[i]]
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i = parent[i]
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return i
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for a, b in adjacent_pairs:
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ra, rb = find(a), find(b)
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if ra != rb:
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parent[ra] = rb
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return [find(i) for i in range(n_faces)]
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def count_islands(n_faces, adjacent_pairs):
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"""union-find 数 UV 岛：n_faces 个面，adjacent_pairs 为 UV 连续的面索引对。"""
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return len(set(island_labels(n_faces, adjacent_pairs)))
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def max_island_area_fraction(labels, abs_areas):
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"""最大单岛 UV 面积占比。"""
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if not labels or not abs_areas:
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return 0.0
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totals = {}
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for lab, area in zip(labels, abs_areas):
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totals[lab] = totals.get(lab, 0.0) + abs(area)
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total = sum(totals.values())
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if total <= 0.0:
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return 0.0
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return max(totals.values()) / total
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def flipped_fraction(signed_areas):
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"""UV 面签名面积为负（翻转）的占比。"""
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if not signed_areas:
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return 0.0
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return sum(1 for a in signed_areas if a < 0) / float(len(signed_areas))
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def fill_ratio(abs_areas):
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"""UV 空间利用率：面积和（重叠会虚高，截断到 1.0）。"""
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return min(1.0, sum(abs_areas))
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# ---------------- 以下仅在 Blender 内执行 ----------------
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def join_meshes(objs):
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"""多 mesh join 成单对象，返回结果对象（bl_bake 复用）。"""
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import bpy
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bpy.ops.object.select_all(action='DESELECT')
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for o in objs:
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o.select_set(True)
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bpy.context.view_layer.objects.active = objs[0]
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if len(objs) > 1:
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bpy.ops.object.join()
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return bpy.context.view_layer.objects.active
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def _apply_modifier(obj, mod):
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import bpy
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bpy.context.view_layer.objects.active = obj
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bpy.ops.object.modifier_apply(modifier=mod.name)
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def _triangulate(obj):
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mod = obj.modifiers.new("mt_tri", 'TRIANGULATE')
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_apply_modifier(obj, mod)
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def _decimate(obj, ratio):
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mod = obj.modifiers.new("mt_dec", 'DECIMATE')
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mod.decimate_type = 'COLLAPSE'
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mod.ratio = ratio
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mod.use_collapse_triangulate = True
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_apply_modifier(obj, mod)
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def _voxel_remesh(obj, voxel_size):
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import bpy
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bpy.context.view_layer.objects.active = obj
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obj.select_set(True)
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mod = obj.modifiers.new("mt_voxel", "REMESH")
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mod.mode = "VOXEL"
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mod.voxel_size = max(float(voxel_size), 1e-4)
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_apply_modifier(obj, mod)
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def _voxel_fallback(obj, target, warnings):
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"""碎叶/非流形上 collapse 会卡在高面数；复制试体素尺寸后重网格，再 collapse。"""
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import bpy
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import mathutils
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bb = [mathutils.Vector(c) for c in obj.bound_box]
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diag = (bb[0] - bb[6]).length
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if diag <= 0.0:
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return len(obj.data.polygons)
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bpy.context.view_layer.objects.active = obj
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obj.select_set(True)
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best_size = diag / 16.0
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best_diff = None
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for div in (12, 16, 20, 24, 32):
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size = diag / float(div)
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bpy.ops.object.duplicate()
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dup = bpy.context.view_layer.objects.active
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_voxel_remesh(dup, size)
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cur = len(dup.data.polygons)
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diff = abs(cur - target)
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if best_diff is None or diff < best_diff:
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best_diff = diff
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best_size = size
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bpy.data.objects.remove(dup, do_unlink=True)
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bpy.context.view_layer.objects.active = obj
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obj.select_set(True)
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_voxel_remesh(obj, best_size)
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cur = len(obj.data.polygons)
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warnings.append(
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"collapse 卡住后改用体素重网格 voxel=%.5f → %d 面" % (best_size, cur)
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)
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if cur > target:
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_decimate(obj, decimate_ratio(target, cur))
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_triangulate(obj)
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cur = len(obj.data.polygons)
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return cur
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def _clean_mesh(obj, warnings):
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"""减面前清理：按局部包围盒对角线相对焊接重合点 + 去退化面，给 collapse 更干净的流形，
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减少被迫加的 seam。各步失败降级不中断。"""
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import bpy
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import mathutils
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bb = [mathutils.Vector(c) for c in obj.bound_box]
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diag = (bb[0] - bb[6]).length
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bpy.context.view_layer.objects.active = obj
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bpy.ops.object.mode_set(mode='EDIT')
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bpy.ops.mesh.select_all(action='SELECT')
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if diag > 0.0:
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try:
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bpy.ops.mesh.remove_doubles(threshold=diag * REL_WELD)
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except RuntimeError as e:
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warnings.append("remove_doubles 失败（%s），跳过焊接" % e)
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else:
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warnings.append("包围盒对角线为 0，跳过焊接")
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try:
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bpy.ops.mesh.dissolve_degenerate()
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except RuntimeError as e:
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warnings.append("dissolve_degenerate 失败（%s），跳过去退化" % e)
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bpy.ops.object.mode_set(mode='OBJECT')
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SEAM_ANGLE_DEG = 66.0 # 锐边阈值：两面夹角超此值标 seam
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PACK_MARGIN = 0.002 # 岛间距 ≈ 2048 图 4px
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UVPM_EXT = "bl_ext.user_default.uvpackmaster4" # UVPackmaster 4 扩展模块名
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UVPM_PIXEL_MARGIN = 4 # UVPM 岛间距（像素），与 PACK_MARGIN * UVPM_TEX_SIZE 同口径
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UVPM_TEX_SIZE = 2048
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UVPM_ROTATION_STEP = 15 # UVPM 旋转步进（度）；比默认 90 更细，利于薄斜条对齐（启发式因引擎崩溃已弃用）
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SEAM_ANGLE_SWEEP = (55.0, 45.0, 35.0, 30.0, 25.0, 20.0, 15.0) # 首选不过门时下探
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STRETCH_ITERS = 30 # minimize_stretch 松弛迭代次数
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REL_WELD = 1e-4 # 焊接距离占局部包围盒对角线比例（避免 cm/m 单位差异导致绝对阈值失准）
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def _clear_uv_layers(mesh):
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while mesh.uv_layers:
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mesh.uv_layers.remove(mesh.uv_layers[0])
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def _unwrap_smart(obj):
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"""Smart UV Project（原路径，也是质量门的回退路径）。"""
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import bpy
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import math
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_clear_uv_layers(obj.data)
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bpy.context.view_layer.objects.active = obj
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bpy.ops.object.mode_set(mode='EDIT')
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bpy.ops.mesh.select_all(action='SELECT')
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bpy.ops.uv.smart_project(angle_limit=math.radians(66.0), island_margin=PACK_MARGIN)
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bpy.ops.object.mode_set(mode='OBJECT')
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def _unwrap_seam(obj, warnings, seam_angle_deg=SEAM_ANGLE_DEG):
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"""锐边标 seam -> MINIMUM_STRETCH/ANGLE_BASED 展开 -> 松弛 -> 纹素均衡 -> pack。
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seam_angle_deg 可变以支持角度扫描；重跑前清掉上一档残留 seam。"""
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import bpy
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import math
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_clear_uv_layers(obj.data)
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obj.data.uv_layers.new()
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bpy.context.view_layer.objects.active = obj
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bpy.ops.object.mode_set(mode='EDIT')
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bpy.ops.mesh.select_mode(type='EDGE')
|
||
# 清掉上一档角度残留 seam（同一对象多角度扫描时必须；同时丢弃源资产自带 seam，保证确定性）
|
||
bpy.ops.mesh.select_all(action='SELECT')
|
||
bpy.ops.mesh.mark_seam(clear=True)
|
||
# 锐边标 seam：接缝只落在硬边处，平滑区域保持整岛
|
||
bpy.ops.mesh.select_all(action='DESELECT')
|
||
bpy.ops.mesh.edges_select_sharp(sharpness=math.radians(seam_angle_deg))
|
||
bpy.ops.mesh.mark_seam(clear=False)
|
||
bpy.ops.mesh.select_all(action='SELECT')
|
||
try:
|
||
bpy.ops.uv.unwrap(method='MINIMUM_STRETCH', margin=PACK_MARGIN)
|
||
except TypeError: # 老版本无 SLIM 枚举
|
||
warnings.append("MINIMUM_STRETCH 不可用，展开改用 ANGLE_BASED")
|
||
bpy.ops.uv.unwrap(method='ANGLE_BASED', margin=PACK_MARGIN)
|
||
try: # 角度松弛：压翻转/拉伸
|
||
bpy.ops.uv.minimize_stretch(iterations=STRETCH_ITERS)
|
||
except (RuntimeError, TypeError) as e:
|
||
warnings.append("minimize_stretch 不可用（%s），跳过松弛" % e)
|
||
try: # 统一纹素密度，避免大岛霸占分辨率
|
||
bpy.ops.uv.average_islands_scale()
|
||
except (RuntimeError, TypeError) as e:
|
||
warnings.append("average_islands_scale 不可用（%s），跳过纹素均衡" % e)
|
||
try:
|
||
bpy.ops.uv.pack_islands(rotate=True, margin=PACK_MARGIN)
|
||
except RuntimeError: # headless 上下文不满足时靠 unwrap 自带打包
|
||
warnings.append("pack_islands 不可用，沿用 unwrap 自带布局")
|
||
bpy.ops.object.mode_set(mode='OBJECT')
|
||
|
||
|
||
def _collect_uv_metrics(obj):
|
||
"""bmesh 提取 UV 指标：岛数（UV 连续边并查集）、利用率、翻转占比、重叠占比。"""
|
||
import bmesh
|
||
bm = bmesh.new()
|
||
bm.from_mesh(obj.data)
|
||
uv = bm.loops.layers.uv.active
|
||
pairs = []
|
||
for e in bm.edges:
|
||
if len(e.link_faces) != 2:
|
||
continue
|
||
f1, f2 = e.link_faces
|
||
cont = True
|
||
for v in e.verts: # 两面在该边两端 UV 一致 => UV 连续（同岛）
|
||
l1 = next(l for l in f1.loops if l.vert == v)
|
||
l2 = next(l for l in f2.loops if l.vert == v)
|
||
if (l1[uv].uv - l2[uv].uv).length > 1e-6:
|
||
cont = False
|
||
break
|
||
if cont:
|
||
pairs.append((f1.index, f2.index))
|
||
signed = []
|
||
for f in bm.faces:
|
||
area = 0.0
|
||
loops = f.loops
|
||
for i in range(len(loops)):
|
||
a = loops[i][uv].uv
|
||
b = loops[(i + 1) % len(loops)][uv].uv
|
||
area += a.x * b.y - b.x * a.y
|
||
signed.append(area * 0.5)
|
||
n = len(bm.faces)
|
||
labels = island_labels(n, pairs)
|
||
abs_areas = [abs(a) for a in signed]
|
||
bm.free()
|
||
return {"islands": len(set(labels)) if n else 0,
|
||
"fill": round(fill_ratio(abs_areas), 4),
|
||
"flipped": round(flipped_fraction(signed), 4),
|
||
"overlap": _overlap_fraction(obj),
|
||
"max_island_frac": round(max_island_area_fraction(labels, abs_areas), 4)}
|
||
|
||
|
||
def _overlap_fraction(obj):
|
||
"""uv.select_overlap 统计重叠 UV 面占比；op 上下文不可用返回 None。"""
|
||
import bpy
|
||
bpy.context.scene.tool_settings.use_uv_select_sync = True
|
||
bpy.context.view_layer.objects.active = obj
|
||
bpy.ops.object.mode_set(mode='EDIT')
|
||
bpy.ops.mesh.select_all(action='DESELECT')
|
||
try:
|
||
bpy.ops.uv.select_overlap()
|
||
except RuntimeError:
|
||
return None
|
||
finally:
|
||
bpy.ops.object.mode_set(mode='OBJECT')
|
||
polys = obj.data.polygons
|
||
if not len(polys):
|
||
return 0.0
|
||
return round(sum(1 for p in polys if p.select) / float(len(polys)), 4)
|
||
|
||
|
||
_uvpm_failed = False # 进程内失败一次即不再重试（避免重复警告与启动开销）
|
||
|
||
|
||
def _uvpm_enable():
|
||
"""启用 UVPM4 扩展（幂等）。headless 下先补丁 GPU shader 创建——
|
||
UVPM4 导入期为视口覆盖层建 shader，后台模式无 GPU 绘图会 SystemError；
|
||
覆盖层仅交互用，pack 不受影响。引擎路径经注册表自动发现。"""
|
||
import bpy
|
||
import addon_utils
|
||
if bpy.app.background:
|
||
import gpu
|
||
orig = gpu.shader.from_builtin
|
||
if not getattr(orig, "_mt_safe", False):
|
||
def _safe(*a, **k):
|
||
try:
|
||
return orig(*a, **k)
|
||
except SystemError:
|
||
return None
|
||
_safe._mt_safe = True
|
||
gpu.shader.from_builtin = _safe
|
||
# default_set=True 才建 preferences.addons 条目（UVPM4 register 依赖）；
|
||
# factory-startup 关闭偏好自动保存，不会写盘
|
||
if addon_utils.enable(UVPM_EXT, default_set=True) is None:
|
||
raise RuntimeError("扩展 %s 启用失败（未安装或版本不兼容）" % UVPM_EXT)
|
||
|
||
|
||
def _uvpm_set(p, name, value, warnings):
|
||
"""防御式设 UVPM 属性：属性存在才设，否则记警告跳过——
|
||
名字不匹配（UVPM 版本差异）时降级为按原 margin 跑 UVPM，不丢整个排布。"""
|
||
if hasattr(p, name):
|
||
try:
|
||
setattr(p, name, value)
|
||
except Exception as e:
|
||
warnings.append("UVPM 属性 %s 设置失败（%s），跳过" % (name, e))
|
||
else:
|
||
warnings.append("UVPM 属性 %s 不存在，跳过" % name)
|
||
|
||
|
||
def _uvpm_repack(obj, warnings):
|
||
"""UVPM4 重排当前 UV 布局，成功返回 True；任何失败记警告返回 False，
|
||
保底布局（pack_islands/smart_project）原样保留。rotation_step 调细以利薄斜条对齐。
|
||
注：UVPM 启发式搜索（heuristic）在 headless 下会随机崩溃引擎进程（Engine process died），
|
||
确定性/稳定性差，故不启用——只用旋转增强这一稳定杠杆。"""
|
||
global _uvpm_failed
|
||
if _uvpm_failed:
|
||
return False
|
||
import bpy
|
||
try:
|
||
_uvpm_enable()
|
||
p = bpy.context.scene.uvpm4_props.default_main_props
|
||
p.pixel_margin_enable = True
|
||
p.pixel_margin = UVPM_PIXEL_MARGIN
|
||
p.pixel_margin_tex_size = UVPM_TEX_SIZE
|
||
_uvpm_set(p, "rotation_enable", True, warnings)
|
||
_uvpm_set(p, "rotation_step", UVPM_ROTATION_STEP, warnings)
|
||
bpy.context.scene.tool_settings.use_uv_select_sync = True
|
||
bpy.context.view_layer.objects.active = obj
|
||
bpy.ops.object.mode_set(mode='EDIT')
|
||
bpy.ops.mesh.select_all(action='SELECT')
|
||
try:
|
||
ret = bpy.ops.uvpackmaster4.pack(mode_id='pack.single_tile',
|
||
pack_op_type='0')
|
||
finally:
|
||
bpy.ops.object.mode_set(mode='OBJECT')
|
||
if 'FINISHED' not in ret:
|
||
raise RuntimeError("pack 返回 %s" % sorted(ret))
|
||
return True
|
||
except Exception as e:
|
||
_uvpm_failed = True
|
||
warnings.append("UVPackmaster 排布不可用（%s），沿用内置 pack 布局" % e)
|
||
return False
|
||
|
||
|
||
def _do_unwrap(obj, mode, warnings, overlap_tol=UV_OVERLAP_TOL):
|
||
"""按模式展开：seam 从 SEAM_ANGLE_DEG 起降序扫 SEAM_ANGLE_SWEEP，首个过门者即选并停扫
|
||
——岛数随角度降单调增，故首个过门者已是过门候选里岛数最少的（pick_best_candidate 据此在
|
||
候选集取岛数最少者，与早停一致；重跑分支为防御：早停下 best 恒为最后一档，通常不触发）；
|
||
全失败退 smart。overlap_tol 覆盖重叠门限（翻转仍严格）。排布 UVPM4 增强，只在最终 UV
|
||
上跑一次，失败保底内置 pack。返回 uv 指标 dict（含 mode）。"""
|
||
if mode == "seam":
|
||
angles = [SEAM_ANGLE_DEG] + list(SEAM_ANGLE_SWEEP)
|
||
candidates = []
|
||
for ang in angles:
|
||
_unwrap_seam(obj, warnings, seam_angle_deg=ang)
|
||
m = _collect_uv_metrics(obj)
|
||
m["angle"] = ang
|
||
candidates.append(m)
|
||
if uv_gate_ok(m["flipped"], m["overlap"], overlap_tol,
|
||
m.get("max_island_frac", 0.0)):
|
||
break # 该档已过门；更低角度只会更碎，无需再试
|
||
best = pick_best_candidate(candidates, overlap_tol)
|
||
if best is not None:
|
||
if best["angle"] != candidates[-1]["angle"]:
|
||
# 选中档不是最后跑的那档，重跑恢复其 UV（_unwrap_seam 会覆盖）
|
||
_unwrap_seam(obj, warnings, seam_angle_deg=best["angle"])
|
||
uvpm = _uvpm_repack(obj, warnings)
|
||
m = _collect_uv_metrics(obj)
|
||
m["mode"] = uvpm_mode_label("seam@%d" % int(best["angle"]), uvpm)
|
||
return m
|
||
detail = "、".join(
|
||
"%d°(翻转%.1f%% 重叠%s 大岛%.1f%%)" % (
|
||
int(c["angle"]), c["flipped"] * 100,
|
||
"%.1f%%" % (c["overlap"] * 100) if c["overlap"] is not None else "未知",
|
||
c.get("max_island_frac", 0.0) * 100)
|
||
for c in candidates)
|
||
warnings.append("所有 seam 角度均未过质量门（%s），回退 smart_project" % detail)
|
||
mode = "smart_fallback"
|
||
_unwrap_smart(obj)
|
||
uvpm = _uvpm_repack(obj, warnings)
|
||
m = _collect_uv_metrics(obj)
|
||
m["mode"] = uvpm_mode_label(mode if mode == "smart_fallback" else "smart", uvpm)
|
||
return m
|
||
|
||
|
||
def _collect_uv_polygons(obj):
|
||
"""提取每个面的 UV 多边形（归一化坐标）：[[[u,v], ...], ...]，供外部 PIL 绘图。
|
||
无 UV 层返回空列表。"""
|
||
import bmesh
|
||
bm = bmesh.new()
|
||
bm.from_mesh(obj.data)
|
||
uv = bm.loops.layers.uv.active
|
||
polys = []
|
||
if uv is not None:
|
||
for f in bm.faces:
|
||
polys.append([[l[uv].uv.x, l[uv].uv.y] for l in f.loops])
|
||
bm.free()
|
||
return polys
|
||
|
||
|
||
def main():
|
||
import bpy
|
||
import json
|
||
argv = sys.argv[sys.argv.index("--") + 1:]
|
||
src, out_fbx, target = argv[0], argv[1], int(argv[2])
|
||
unwrap_mode = argv[3] if len(argv) > 3 else "seam"
|
||
overlap_tol = float(argv[4]) if len(argv) > 4 and argv[4] else UV_OVERLAP_TOL
|
||
warnings = []
|
||
|
||
bpy.ops.wm.read_factory_settings(use_empty=True)
|
||
imported = import_model_objects(src)
|
||
meshes = [o for o in imported if o.type == 'MESH']
|
||
skipped = [o.name for o in imported if o.type != 'MESH']
|
||
if skipped:
|
||
warnings.append("忽略非 mesh 对象：%s（本工具只处理静态网格）" % ", ".join(skipped))
|
||
if not meshes:
|
||
print("MT_SUMMARY " + json.dumps({"error": "输入模型中没有 mesh"}, ensure_ascii=False))
|
||
return
|
||
obj = join_meshes(meshes)
|
||
|
||
_clean_mesh(obj, warnings)
|
||
_triangulate(obj)
|
||
orig = len(obj.data.polygons)
|
||
cur = orig
|
||
if cur <= target:
|
||
warnings.append("当前 %d 面 <= 目标 %d，跳过减面" % (cur, target))
|
||
else:
|
||
# collapse 结果是近似值；未达容差时按新面数修正 ratio 再来，最多 MAX_RETRY 轮
|
||
for _ in range(1 + MAX_RETRY):
|
||
_decimate(obj, decimate_ratio(target, cur))
|
||
_triangulate(obj) # collapse triangulate 后仍可能残留非三角面
|
||
cur = len(obj.data.polygons)
|
||
if within_tolerance(target, cur) or cur <= target:
|
||
break
|
||
# 重试用尽仍超差且偏多：记录警告，交由上层决定是否可接受
|
||
if not within_tolerance(target, cur) and cur > target:
|
||
warnings.append("修正 %d 轮后仍超差：%d 面（目标 %d ±3%%）" % (MAX_RETRY, cur, target))
|
||
if cur > max(target * 2, target + 500):
|
||
cur = _voxel_fallback(obj, target, warnings)
|
||
|
||
uv_info = _do_unwrap(obj, unwrap_mode, warnings, overlap_tol)
|
||
uv_png = os.path.splitext(os.path.abspath(out_fbx))[0] + "_uv.png"
|
||
uv_polys_json = os.path.splitext(os.path.abspath(out_fbx))[0] + "_uv.polys.json"
|
||
uv_preview = None
|
||
try:
|
||
polys = _collect_uv_polygons(obj)
|
||
os.makedirs(os.path.dirname(uv_polys_json), exist_ok=True)
|
||
with open(uv_polys_json, "w", encoding="utf-8") as fp:
|
||
json.dump(polys, fp)
|
||
uv_preview = uv_png # 目标 PNG；实际绘制由 model_decimate（系统 Python + PIL）完成
|
||
except Exception as e:
|
||
warnings.append("UV 几何导出失败（%s），跳过观察图" % e)
|
||
out_dir = os.path.dirname(os.path.abspath(out_fbx))
|
||
os.makedirs(out_dir, exist_ok=True)
|
||
# 仅导出合并后的对象；整场景导出会把 armature/empty 等非 mesh 带进 _low.fbx
|
||
bpy.ops.export_scene.fbx(filepath=out_fbx, use_selection=True,
|
||
path_mode='STRIP', embed_textures=False)
|
||
|
||
print("MT_SUMMARY " + json.dumps(
|
||
{"src": os.path.basename(src), "fbx": os.path.basename(out_fbx),
|
||
"tris_before": orig, "tris_after": cur, "target": target,
|
||
"uv": uv_info,
|
||
"uv_preview": uv_preview,
|
||
"uv_polys": uv_polys_json if uv_preview else None,
|
||
"warnings": warnings},
|
||
ensure_ascii=False))
|
||
|
||
|
||
if __name__ == "__main__" and "--" in sys.argv:
|
||
main()
|