blender/io_mspgl/mesh.py

   1 import bpy
   2 import math
   3 import mathutils
   4 import itertools
   5
   6 def make_edge_key(i1, i2):
   7         return (min(i1, i2), max(i1, i2))
   8
   9 class Edge:
  10         def __init__(self, edge):
  11                 if edge.__class__==Edge:
  12                         self.smooth = edge.smooth
  13                 else:
  14                         self.smooth = False
  15                 if edge:
  16                         self.vertices = edge.vertices[:]
  17                         self.key = edge.key
  18                 else:
  19                         self.vertices = []
  20                         self.key = None
  21                 self.faces = []
  22
  23         def check_smooth(self, limit):
  24                 if len(self.faces)!=2:
  25                         return
  26
  27                 d = self.faces[0].normal.dot(self.faces[1].normal)
  28                 self.smooth = ((d>limit and self.faces[0].use_smooth and self.faces[1].use_smooth) or d>0.99995)
  29
  30         def other_face(self, f):
  31                 if f.index==self.faces[0].index:
  32                         if len(self.faces)>=2:
  33                                 return self.faces[1]
  34                         else:
  35                                 return None
  36                 else:
  37                         return self.faces[0]
  38
  39         def other_vertex(self, v):
  40                 if v.index==self.vertices[0].index:
  41                         return self.vertices[1]
  42                 else:
  43                         return self.vertices[0]
  44
  45
  46 class Vertex:
  47         def __init__(self, vertex):
  48                 if vertex.__class__==Vertex:
  49                         self.uvs = vertex.uvs[:]
  50                         self.tan = vertex.tan
  51                         self.bino = vertex.bino
  52                 else:
  53                         self.uvs = []
  54                         self.tan = None
  55                         self.bino = None
  56                 self.index = vertex.index
  57                 self.co = mathutils.Vector(vertex.co)
  58                 self.normal = mathutils.Vector(vertex.normal)
  59                 self.flag = False
  60                 self.edges = []
  61                 self.faces = []
  62                 self.groups = vertex.groups[:]
  63
  64         def __cmp__(self, other):
  65                 if other is None:
  66                         return 1
  67                 return cmp(self.index, other.index)
  68
  69
  70 class VertexGroup:
  71         def __init__(self, group):
  72                 self.group = group.group
  73                 self.weight = group.weight
  74
  75
  76 class Face:
  77         def __init__(self, face):
  78                 self.index = face.index
  79                 self.edges = []
  80                 self.edge_keys = face.edge_keys
  81                 self.vertices = face.vertices[:]
  82                 self.loop_indices = face.loop_indices
  83                 self.normal = face.normal
  84                 self.use_smooth = face.use_smooth
  85                 self.material_index = face.material_index
  86                 self.flag = False
  87
  88         def __cmp__(self, other):
  89                 if other is None:
  90                         return 1
  91                 return cmp(self.index, other.index)
  92
  93         def pivot_vertex(self, v):
  94                 n = self.vertices.index(v)
  95                 return [(n+i)%len(self.vertices) for i in range(len(self.vertices))]
  96
  97         def get_loop_index(self, v):
  98                 return self.loop_indices[self.vertices.index(v)]
  99
 100         def get_edge(self, v1, v2):
 101                 key = make_edge_key(v1.index, v2.index)
 102                 for e in self.edges:
 103                         if e.key==key:
 104                                 return e
 105                 raise KeyError("No edge %s"%(key,))
 106
 107         def other_edge(self, e, v):
 108                 for d in self.edges:
 109                         if d!=e and v in d.vertices:
 110                                 return d
 111
 112         def get_neighbors(self):
 113                 neighbors = [e.other_face(self) for e in self.edges]
 114                 return list(filter(bool, neighbors))
 115
 116
 117 class Line:
 118         def __init__(self, e):
 119                 self.edge = e
 120                 self.vertices = e.vertices[:]
 121                 self.flag = False
 122
 123
 124 class UvLayer:
 125         def __init__(self, arg):
 126                 if type(arg)==str:
 127                         self.name = arg
 128                         self.uvs = []
 129                 else:
 130                         self.name = arg.name
 131                         self.uvs = [mathutils.Vector(d.uv) for d in arg.data]
 132
 133                 self.unit = None
 134                 self.hidden = False
 135
 136                 dot = self.name.find('.')
 137                 if dot>=0:
 138                         ext = self.name[dot:]
 139                         if ext.startswith(".unit") and ext[5:].isdigit():
 140                                 self.unit = int(ext[5:])
 141                         elif ext==".hidden":
 142                                 self.hidden = True
 143
 144
 145 class Mesh:
 146         def __init__(self, mesh):
 147                 self.name = mesh.name
 148
 149                 self.winding_test = mesh.winding_test
 150                 self.smoothing = mesh.smoothing
 151                 self.use_uv = mesh.use_uv
 152                 self.tbn_vecs = mesh.tbn_vecs
 153                 self.tbn_uvtex = mesh.tbn_uvtex
 154                 self.vertex_groups = mesh.vertex_groups
 155
 156                 # Clone basic data
 157                 self.vertices = [Vertex(v) for v in mesh.vertices]
 158                 for v in self.vertices:
 159                         v.groups = [VertexGroup(g) for g in v.groups]
 160
 161                 self.faces = [Face(f) for f in mesh.polygons]
 162                 self.edges = [Edge(e) for e in mesh.edges]
 163                 self.loops = mesh.loops[:]
 164                 self.materials = mesh.materials[:]
 165
 166                 self.use_auto_smooth = mesh.use_auto_smooth
 167                 self.auto_smooth_angle = mesh.auto_smooth_angle
 168
 169                 # Clone only the desired UV layers
 170                 if mesh.use_uv=='NONE' or not mesh.uv_layers:
 171                         self.uv_layers = []
 172                 else:
 173                         self.uv_layers = [UvLayer(u) for u in mesh.uv_layers]
 174
 175                         # Assign texture unit numbers to UV layers that lack one
 176                         missing_unit = [u for u in self.uv_layers if u.unit is None]
 177                         if missing_unit:
 178                                 missing_unit = sorted(missing_unit, key=(lambda u: u.name))
 179                                 used_units = [u.unit for u in self.uv_layers if u.unit is not None]
 180                                 for u, n in zip(missing_unit, (i for i in itertools.count() if i not in used_units)):
 181                                         u.unit = n
 182
 183                         self.uv_layers = sorted(self.uv_layers, key=(lambda u: u.unit))
 184
 185                         if mesh.use_uv=='UNIT0':
 186                                 self.uv_layers = [self.uv_layers[0]]
 187                                 if self.uv_layers[0].unit!=0:
 188                                         self.uv_layers = []
 189
 190                 # Rewrite links between elements to point to cloned data, or create links
 191                 # where they don't exist
 192                 edge_map = {e.key: e for e in self.edges}
 193                 for f in self.faces:
 194                         if len(f.vertices)>4:
 195                                 raise ValueError("Ngons are not supported")
 196
 197                         f.vertices = [self.vertices[i] for i in f.vertices]
 198                         for v in f.vertices:
 199                                 v.faces.append(f)
 200
 201                         for k in f.edge_keys:
 202                                 e = edge_map[k]
 203                                 e.faces.append(f)
 204                                 f.edges.append(e)
 205
 206                 for e in self.edges:
 207                         e.vertices = [self.vertices[i] for i in e.vertices]
 208                         for v in e.vertices:
 209                                 v.edges.append(e)
 210
 211                 # Store loose edges as lines
 212                 if mesh.use_lines:
 213                         self.lines = [Line(e) for e in self.edges if not e.faces]
 214                 else:
 215                         self.lines = []
 216
 217                 self.vertex_sequence = []
 218
 219         def transform(self, matrix):
 220                 for v in self.vertices:
 221                         v.co = matrix@v.co
 222
 223         def splice(self, other):
 224                 if len(self.uv_layers)!=len(other.uv_layers):
 225                         raise ValueError("Meshes have incompatible UV layers")
 226                 for i, u in enumerate(self.uv_layers):
 227                         if u.name!=other.uv_layers[i].name:
 228                                 raise ValueError("Meshes have incompatible UV layers")
 229
 230                 # Merge materials and form a lookup from source material indices to the
 231                 # merged material list
 232                 material_map = []
 233                 for m in other.materials:
 234                         if m in self.materials:
 235                                 material_map.append(self.materials.index(m))
 236                         else:
 237                                 material_map.append(len(self.materials))
 238                                 self.materials.append(m)
 239
 240                 # Append data and adjust indices where necessary.  Since the data is
 241                 # spliced from the source mesh, rebuilding references is not necessary.
 242                 for i, u in enumerate(self.uv_layers):
 243                         u.uvs += other.uv_layers[i].uvs
 244
 245                 offset = len(self.vertices)
 246                 self.vertices += other.vertices
 247                 for v in self.vertices[offset:]:
 248                         v.index += offset
 249
 250                 loop_offset = len(self.loops)
 251                 self.loops += other.loops
 252
 253                 offset = len(self.faces)
 254                 self.faces += other.faces
 255                 for f in self.faces[offset:]:
 256                         f.index += offset
 257                         f.loop_indices = range(f.loop_indices.start+offset, f.loop_indices.stop+offset)
 258                         if other.materials:
 259                                 f.material_index = material_map[f.material_index]
 260
 261                 offset = len(self.edges)
 262                 self.edges += other.edges
 263                 for e in self.edges[offset:]:
 264                         e.index += offset
 265                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 266
 267                 self.lines += other.lines
 268
 269         def prepare_triangles(self, progress):
 270                 face_count = len(self.faces)
 271                 for i in range(face_count):
 272                         f = self.faces[i]
 273                         nverts = len(f.vertices)
 274                         if nverts==3:
 275                                 continue
 276
 277                         # Calculate normals at each vertex of the face
 278                         edge_vecs = []
 279                         for j in range(nverts):
 280                                 edge_vecs.append(f.vertices[(j+1)%nverts].co-f.vertices[j].co)
 281
 282                         normals = []
 283                         for j in range(nverts):
 284                                 normals.append(edge_vecs[j-1].cross(edge_vecs[j]).normalized())
 285
 286                         # Check which diagonal results in a flatter triangulation
 287                         flatness1 = normals[0].dot(normals[2])
 288                         flatness2 = normals[1].dot(normals[3])
 289                         cut_index = 1 if flatness1>flatness2 else 0
 290
 291                         nf = Face(f)
 292                         nf.index = len(self.faces)
 293                         self.faces.append(nf)
 294
 295                         ne = Edge(None)
 296                         ne.index = len(self.edges)
 297                         self.edges.append(ne)
 298
 299                         nf.vertices = [f.vertices[cut_index], f.vertices[2], f.vertices[3]]
 300                         nf.loop_indices = [f.loop_indices[cut_index], f.loop_indices[2], f.loop_indices[3]]
 301                         for v in nf.vertices:
 302                                 v.faces.append(nf)
 303
 304                         ne.vertices = [f.vertices[cut_index], f.vertices[2+cut_index]]
 305                         for v in ne.vertices:
 306                                 v.edges.append(ne)
 307                         ne.key = make_edge_key(ne.vertices[0].index, ne.vertices[1].index)
 308                         ne.smooth = True
 309
 310                         f.vertices[3-cut_index].faces.remove(f)
 311                         del f.vertices[3-cut_index]
 312                         f.loop_indices = [f.loop_indices[0], f.loop_indices[1], f.loop_indices[2+cut_index]]
 313
 314                         ne.faces = [f, nf]
 315                         if cut_index==0:
 316                                 nf.edges = [ne, f.edges[2], f.edges[3]]
 317                                 f.edges = [f.edges[0], f.edges[1], ne]
 318                         else:
 319                                 nf.edges = [f.edges[1], f.edges[2], ne]
 320                                 f.edges = [f.edges[0], ne, f.edges[3]]
 321                         for e in nf.edges:
 322                                 if e!=ne:
 323                                         e.faces.remove(f)
 324                                         e.faces.append(nf)
 325
 326                         f.normal = normals[1-cut_index]
 327                         nf.normal = normals[3-cut_index]
 328
 329                         progress.set_progress(i/face_count)
 330
 331         def prepare_smoothing(self, progress):
 332                 smooth_limit = -1
 333                 if self.smoothing=='NONE':
 334                         for f in self.faces:
 335                                 f.use_smooth = False
 336
 337                         smooth_limit = 1
 338                 elif self.use_auto_smooth:
 339                         smooth_limit = math.cos(self.auto_smooth_angle)
 340
 341                 for e in self.edges:
 342                         e.check_smooth(smooth_limit)
 343
 344                 progress.push_task("Sharp edges", 0.0, 0.7)
 345                 self.split_vertices(self.find_smooth_group, progress)
 346
 347                 if self.smoothing!='BLENDER':
 348                         progress.set_task("Updating normals", 0.7, 1.0)
 349                         self.compute_normals(progress)
 350
 351                 progress.pop_task()
 352
 353         def prepare_vertex_groups(self, obj):
 354                 for v in self.vertices:
 355                         if v.groups:
 356                                 weight_sum = sum(g.weight for g in v.groups)
 357                                 v.groups = sorted(v.groups, key=(lambda g: g.weight), reverse=True)[:self.max_groups_per_vertex]
 358                                 weight_scale = weight_sum/sum(g.weight for g in v.groups)
 359                                 for g in v.groups:
 360                                         g.weight *= weight_scale
 361
 362                 if obj.parent and obj.parent.type=="ARMATURE":
 363                         armature = obj.parent.data
 364                         bone_indices = {b.name: i for i, b in enumerate(armature.bones)}
 365                         group_index_map = {i: i for i in range(len(obj.vertex_groups))}
 366                         for g in first_obj.vertex_groups:
 367                                 if g.name in bone_indices:
 368                                         group_index_map[g.index] = bone_indices[g.name]
 369
 370                         for v in self.vertices:
 371                                 for g in v.groups:
 372                                         g.group = group_index_map[g.group]
 373
 374         def apply_material_map(self, material_map):
 375                 for m in self.materials:
 376                         if m.name not in material_map.material_names:
 377                                 raise Exception("Material map is not compatible with Mesh")
 378
 379                 if self.use_uv=='NONE':
 380                         return
 381
 382                 layer = UvLayer("material_map")
 383                 if self.use_uv=='UNIT0':
 384                         self.uv_layers = [layer]
 385                         layer.unit = 0
 386                 else:
 387                         self.uv_layers.append(layer)
 388                         used_units = [u.unit for u in self.uv_layers]
 389                         layer.unit = next(i for i in itertools.count() if i not in used_units)
 390                         self.uv_layers.sort(key=lambda u: u.unit)
 391
 392                 layer.uvs = [(0.0, 0.0)]*len(self.loops)
 393                 for f in self.faces:
 394                         uv = material_map.get_material_uv(self.materials[f.material_index])
 395                         for i in f.loop_indices:
 396                                 layer.uvs[i] = uv
 397
 398         def prepare_uv(self, progress):
 399                 # Form a list of UV layers referenced by materials with the array atlas
 400                 # property set
 401                 array_uv_layers = [] #[t.uv_layer for m in self.materials if m.array_atlas for t in m.texture_slots if t and t.texture_coords=='UV']
 402                 array_uv_layers = [u for u in self.uv_layers if u.name in array_uv_layers]
 403
 404                 if array_uv_layers:
 405                         for f in self.faces:
 406                                 layer = 0
 407                                 if f.material_index<len(self.materials):
 408                                         mat = self.materials[f.material_index]
 409                                         if mat and mat.array_atlas:
 410                                                 layer = mat.array_layer
 411
 412                                 for l in array_uv_layers:
 413                                         for i in f.loop_indices:
 414                                                 l.uvs[i] = mathutils.Vector((*l.uvs[i], layer))
 415
 416                 prog_count = len(self.uv_layers)
 417                 prog_step = 0
 418
 419                 # Split by the UV layer used for TBN vectors first so connectivity
 420                 # remains intact for TBN vector computation
 421                 tbn_layer_index = -1
 422                 if self.tbn_vecs:
 423                         uv_names = [u.name for u in self.uv_layers]
 424                         if self.tbn_uvtex in uv_names:
 425                                 prog_count += 1
 426                                 tbn_layer_index = uv_names.index(self.tbn_uvtex)
 427                                 progress.push_task_slice("Computing TBN", 0, prog_count)
 428                                 self.split_vertices(self.find_uv_group, progress, tbn_layer_index)
 429                                 progress.set_task_slice(self.tbn_uvtex, 1, prog_count)
 430                                 self.compute_tbn(tbn_layer_index, progress)
 431                                 progress.pop_task()
 432                                 prog_step = 2
 433                         else:
 434                                 raise Exception("TBN UV layer not found")
 435
 436                 # Split by the remaining UV layers
 437                 for i, u in enumerate(self.uv_layers):
 438                         if i==tbn_layer_index:
 439                                 continue
 440
 441                         progress.push_task_slice(u.name, prog_step, prog_count)
 442                         self.split_vertices(self.find_uv_group, progress, i)
 443                         progress.pop_task()
 444                         prog_step += 1
 445
 446                 # Copy UVs from layers to vertices
 447                 for v in self.vertices:
 448                         if v.faces:
 449                                 # All faces still connected to the vertex have the same UV value
 450                                 f = v.faces[0]
 451                                 i = f.get_loop_index(v)
 452                                 v.uvs = [u.uvs[i] for u in self.uv_layers]
 453                         else:
 454                                 v.uvs = [(0.0, 0.0)]*len(self.uv_layers)
 455
 456         def split_vertices(self, find_group_func, progress, *args):
 457                 vertex_count = len(self.vertices)
 458                 for i in range(vertex_count):
 459                         v = self.vertices[i]
 460                         for f in v.faces:
 461                                 f.flag = False
 462
 463                         # Find all groups of faces on this vertex
 464                         groups = []
 465                         for f in v.faces:
 466                                 if not f.flag:
 467                                         groups.append(find_group_func(v, f, *args))
 468
 469                         # Give groups after the first separate copies of the vertex
 470                         for g in groups[1:]:
 471                                 nv = Vertex(v)
 472                                 nv.index = len(self.vertices)
 473                                 self.vertices.append(nv)
 474
 475                                 for e in v.edges:
 476                                         e_faces_in_g = [f for f in e.faces if f in g]
 477                                         if not e_faces_in_g:
 478                                                 continue
 479
 480                                         if len(e_faces_in_g)<len(e.faces):
 481                                                 # Create a copy of an edge at the boundary of the group
 482                                                 ne = Edge(e)
 483                                                 ne.index = len(self.edges)
 484                                                 self.edges.append(ne)
 485
 486                                                 ne.other_vertex(v).edges.append(ne)
 487
 488                                                 for f in e_faces_in_g:
 489                                                         e.faces.remove(f)
 490                                                         f.edges[f.edges.index(e)] = ne
 491                                                         ne.faces.append(f)
 492
 493                                                 e = ne
 494
 495                                         e.vertices[e.vertices.index(v)] = nv
 496                                         nv.edges.append(e)
 497
 498                                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 499
 500                                 # Filter out any edges that were removed from the original vertex
 501                                 v.edges = [e for e in v.edges if v in e.vertices]
 502
 503                                 for f in g:
 504                                         v.faces.remove(f)
 505                                         f.vertices[f.vertices.index(v)] = nv
 506                                         nv.faces.append(f)
 507
 508                         progress.set_progress(i/vertex_count)
 509
 510         def find_smooth_group(self, vertex, face):
 511                 face.flag = True
 512
 513                 edges = [e for e in face.edges if vertex in e.vertices]
 514
 515                 group = [face]
 516                 for e in edges:
 517                         f = face
 518                         while e.smooth:
 519                                 f = e.other_face(f)
 520                                 if not f or f.flag:
 521                                         break
 522
 523                                 f.flag = True
 524                                 group.append(f)
 525                                 e = f.other_edge(e, vertex)
 526
 527                 return group
 528
 529         def find_uv_group(self, vertex, face, index):
 530                 layer = self.uv_layers[index]
 531                 uv = layer.uvs[face.get_loop_index(vertex)]
 532                 face.flag = True
 533
 534                 group = [face]
 535                 for f in vertex.faces:
 536                         if not f.flag and layer.uvs[f.get_loop_index(vertex)]==uv:
 537                                 f.flag = True
 538                                 group.append(f)
 539
 540                 return group
 541
 542         def compute_normals(self, progress):
 543                 for i, v in enumerate(self.vertices):
 544                         v.normal = mathutils.Vector()
 545                         for f in v.faces:
 546                                 vi = f.pivot_vertex(v)
 547                                 edge1 = f.vertices[vi[1]].co-v.co
 548                                 edge2 = f.vertices[vi[-1]].co-v.co
 549                                 if edge1.length and edge2.length:
 550                                         # Use the angle between edges as a weighting factor.  This gives
 551                                         # more consistent normals on bends with an inequal number of
 552                                         # faces on each side.
 553                                         v.normal += f.normal*edge1.angle(edge2)
 554
 555                         if v.normal.length:
 556                                 v.normal.normalize()
 557                         else:
 558                                 v.normal = mathutils.Vector((0, 0, 1))
 559
 560                         progress.set_progress(i/len(self.vertices))
 561
 562         def compute_tbn(self, index, progress):
 563                 # This function is called at an early stage during UV preparation when
 564                 # face UVs are not available yet
 565                 layer_uvs = self.uv_layers[index].uvs
 566
 567                 for i, v in enumerate(self.vertices):
 568                         v.tan = mathutils.Vector()
 569                         v.bino = mathutils.Vector()
 570                         for f in v.faces:
 571                                 vi = f.pivot_vertex(v)
 572                                 uv0 = layer_uvs[f.loop_indices[vi[0]]]
 573                                 uv1 = layer_uvs[f.loop_indices[vi[1]]]
 574                                 uv2 = layer_uvs[f.loop_indices[vi[-1]]]
 575                                 du1 = uv1[0]-uv0[0]
 576                                 du2 = uv2[0]-uv0[0]
 577                                 dv1 = uv1[1]-uv0[1]
 578                                 dv2 = uv2[1]-uv0[1]
 579                                 edge1 = f.vertices[vi[1]].co-f.vertices[vi[0]].co
 580                                 edge2 = f.vertices[vi[-1]].co-f.vertices[vi[0]].co
 581                                 div = (du1*dv2-du2*dv1)
 582                                 if div:
 583                                         mul = edge1.angle(edge2)/div
 584                                         v.tan += (edge1*dv2-edge2*dv1)*mul
 585                                         v.bino += (edge2*du1-edge1*du2)*mul
 586
 587                         if v.tan.length:
 588                                 v.tan.normalize()
 589                         if v.bino.length:
 590                                 v.bino.normalize()
 591
 592                         progress.set_progress(i/len(self.vertices))
 593
 594         def prepare_sequence(self, progress):
 595                 progress.push_task("Reordering faces", 0.0, 0.5)
 596                 self.reorder_faces(progress)
 597
 598                 progress.set_task("Building sequence", 0.5, 1.0)
 599                 sequence = None
 600                 for i, f in enumerate(self.faces):
 601                         if sequence:
 602                                 if len(sequence)==3:
 603                                         # Rotate the first three vertices so that the new face can be added
 604                                         if sequence[0] in f.vertices and sequence[1] not in f.vertices:
 605                                                 sequence.append(sequence[0])
 606                                                 del sequence[0]
 607                                         elif sequence[2] not in f.vertices and sequence[1] in f.vertices:
 608                                                 sequence.insert(0, sequence[-1])
 609                                                 del sequence[-1]
 610
 611                                 if sequence[-1] not in f.vertices:
 612                                         sequence = None
 613                                 else:
 614                                         to_add = [v for v in f.vertices if v!=sequence[-1] and v!=sequence[-2]]
 615                                         if len(to_add)==2:
 616                                                 if (f.vertices[1]==sequence[-1]) != (len(sequence)%2==1):
 617                                                         to_add.reverse()
 618                                                 sequence.append(sequence[-1])
 619                                         sequence += to_add
 620
 621                         if not sequence:
 622                                 sequence = f.vertices[:]
 623                                 self.vertex_sequence.append(sequence)
 624
 625                         progress.set_progress(i/len(self.faces))
 626
 627                 progress.pop_task()
 628
 629                 self.reorder_vertices()
 630
 631         def reorder_faces(self, progress):
 632                 # Tom Forsyth's vertex cache optimization algorithm
 633                 # http://eelpi.gotdns.org/papers/fast_vert_cache_opt.html
 634
 635                 for f in self.faces:
 636                         f.flag = False
 637
 638                 last_triangle_score = 0.75
 639                 cache_decay_power = 1.5
 640                 valence_boost_scale = 2.0
 641                 valence_boost_power = -0.5
 642
 643                 max_cache_size = 32
 644                 cached_vertices = []
 645
 646                 # Keep track of the score and number of unused faces for each vertex
 647                 vertex_info = [[0, len(v.faces)] for v in self.vertices]
 648                 for vi in vertex_info:
 649                         vi[0] = valence_boost_scale*(vi[1]**valence_boost_power)
 650
 651                 face = None
 652                 reordered_faces = []
 653
 654                 n_processed = 0
 655                 while 1:
 656                         if not face:
 657                                 # Previous iteration gave no candidate for best face (or this is
 658                                 # the first iteration).  Scan all faces for the highest score.
 659                                 best_score = 0
 660                                 for f in self.faces:
 661                                         if f.flag:
 662                                                 continue
 663
 664                                         score = sum(vertex_info[v.index][0] for v in f.vertices)
 665                                         if score>best_score:
 666                                                 best_score = score
 667                                                 face = f
 668
 669                         if not face:
 670                                 break
 671
 672                         reordered_faces.append(face)
 673                         face.flag = True
 674
 675                         for v in face.vertices:
 676                                 vertex_info[v.index][1] -= 1
 677
 678                                 # Shuffle the vertex into the front of the cache
 679                                 if v in cached_vertices:
 680                                         cached_vertices.remove(v)
 681                                 cached_vertices.insert(0, v)
 682
 683                         # Update scores for all vertices in the cache
 684                         for i, v in enumerate(cached_vertices):
 685                                 score = 0
 686                                 if i<3:
 687                                         score += last_triangle_score
 688                                 elif i<max_cache_size:
 689                                         score += (1-(i-3)/(max_cache_size-3))**cache_decay_power
 690                                 if vertex_info[v.index][1]:
 691                                         score += valence_boost_scale*(vertex_info[v.index][1]**valence_boost_power)
 692                                 vertex_info[v.index][0] = score
 693
 694                         face = None
 695                         best_score = 0
 696                         for v in cached_vertices:
 697                                 for f in v.faces:
 698                                         if not f.flag:
 699                                                 score = sum(vertex_info[fv.index][0] for fv in f.vertices)
 700                                                 if score>best_score:
 701                                                         best_score = score
 702                                                         face = f
 703
 704                         del cached_vertices[max_cache_size:]
 705
 706                         n_processed += 1
 707                         progress.set_progress(n_processed/len(self.faces))
 708
 709                 self.faces = reordered_faces
 710                 for i, f in enumerate(self.faces):
 711                         f.index = i
 712
 713         def reorder_vertices(self):
 714                 for v in self.vertices:
 715                         v.index = -1
 716
 717                 reordered_vertices = []
 718                 for s in self.vertex_sequence:
 719                         for v in s:
 720                                 if v.index<0:
 721                                         v.index = len(reordered_vertices)
 722                                         reordered_vertices.append(v)
 723
 724                 self.vertices = reordered_vertices
 725
 726                 for e in self.edges:
 727                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 728
 729
 730 def create_mesh_from_object(context, obj, progress, *, material_map=None):
 731         if obj.type!="MESH":
 732                 raise Exception("Object is not a mesh")
 733
 734         progress.push_task("Preparing mesh", 0.0, 0.2)
 735
 736         objs = [(obj, mathutils.Matrix())]
 737         i = 0
 738         while i<len(objs):
 739                 o, m = objs[i]
 740                 i += 1
 741                 for c in o.children:
 742                         if c.type=="MESH" and c.compound:
 743                                 objs.append((c, m*c.matrix_local))
 744
 745         dg = context.evaluated_depsgraph_get()
 746
 747         mesh = None
 748         for o, m in objs:
 749                 eval_obj = o.evaluated_get(dg)
 750                 bmesh = eval_obj.to_mesh()
 751
 752                 # Object.to_mesh does not copy custom properties
 753                 bmesh.winding_test = o.data.winding_test
 754                 bmesh.smoothing = o.data.smoothing
 755                 bmesh.use_lines = o.data.use_lines
 756                 bmesh.vertex_groups = o.data.vertex_groups
 757                 bmesh.max_groups_per_vertex = o.data.max_groups_per_vertex
 758                 bmesh.use_uv = o.data.use_uv
 759                 bmesh.tbn_vecs = o.data.tbn_vecs
 760                 bmesh.tbn_uvtex = o.data.tbn_uvtex
 761
 762                 me = Mesh(bmesh)
 763                 me.transform(m)
 764
 765                 for i, s in enumerate(eval_obj.material_slots):
 766                         if s.link=='OBJECT':
 767                                 me.materials[i] = s.material
 768
 769                 if mesh:
 770                         mesh.splice(me)
 771                 else:
 772                         mesh = me
 773
 774         mesh.name = obj.data.name
 775
 776         if material_map:
 777                 mesh.apply_material_map(material_map)
 778
 779         progress.set_task("Triangulating", 0.2, 0.3)
 780         mesh.prepare_triangles(progress)
 781         progress.set_task("Smoothing", 0.3, 0.5)
 782         mesh.prepare_smoothing(progress)
 783         progress.set_task("Vertex groups", 0.5, 0.6)
 784         mesh.prepare_vertex_groups(obj)
 785         progress.set_task("Preparing UVs", 0.6, 0.8)
 786         mesh.prepare_uv(progress)
 787         progress.set_task("Render sequence", 0.8, 1.0)
 788         mesh.prepare_sequence(progress)
 789
 790         progress.pop_task()
 791
 792         return mesh