blender/io_mspgl/mesh.py

   1 import bpy
   2 import math
   3 import mathutils
   4
   5 def make_edge_key(i1, i2):
   6         return (min(i1, i2), max(i1, i2))
   7
   8 class Edge:
   9         def __init__(self, edge):
  10                 if edge.__class__==Edge:
  11                         self._edge = edge._edge
  12                         self.smooth = edge.smooth
  13                 else:
  14                         self._edge = edge
  15                         self.smooth = False
  16                 if edge:
  17                         self.vertices = edge.vertices[:]
  18                         self.key = edge.key
  19                 else:
  20                         self.vertices = []
  21                         self.key = None
  22                 self.faces = []
  23
  24         def __getattr__(self, attr):
  25                 return getattr(self._edge, attr)
  26
  27         def check_smooth(self, limit):
  28                 if len(self.faces)!=2:
  29                         return
  30
  31                 d = self.faces[0].normal.dot(self.faces[1].normal)
  32                 self.smooth = ((d>limit and self.faces[0].use_smooth and self.faces[1].use_smooth) or d>0.99995)
  33
  34         def other_face(self, f):
  35                 if f.index==self.faces[0].index:
  36                         if len(self.faces)>=2:
  37                                 return self.faces[1]
  38                         else:
  39                                 return None
  40                 else:
  41                         return self.faces[0]
  42
  43         def other_vertex(self, v):
  44                 if v.index==self.vertices[0].index:
  45                         return self.vertices[1]
  46                 else:
  47                         return self.vertices[0]
  48
  49
  50 class Vertex:
  51         def __init__(self, vertex):
  52                 if vertex.__class__==Vertex:
  53                         self._vertex = vertex._vertex
  54                         self.uvs = vertex.uvs[:]
  55                         self.tan = vertex.tan
  56                         self.bino = vertex.bino
  57                 else:
  58                         self._vertex = vertex
  59                         self.uvs = []
  60                         self.tan = None
  61                         self.bino = None
  62                 self.index = vertex.index
  63                 self.co = vertex.co
  64                 self.normal = vertex.normal
  65                 self.flag = False
  66                 self.edges = []
  67                 self.faces = []
  68                 self.groups = vertex.groups[:]
  69
  70         def __getattr__(self, attr):
  71                 return getattr(self._vertex, attr)
  72
  73         def __cmp__(self, other):
  74                 if other is None:
  75                         return 1
  76                 return cmp(self.index, other.index)
  77
  78
  79 class VertexGroup:
  80         def __init__(self, group):
  81                 self._group = group
  82                 self.group = group.group
  83                 self.weight = group.weight
  84
  85         def __getattr__(self, attr):
  86                 return getattr(self._group, attr)
  87
  88
  89 class Face:
  90         def __init__(self, face):
  91                 self._face = face
  92                 self.index = face.index
  93                 self.edges = []
  94                 self.vertices = face.vertices[:]
  95                 self.uvs = []
  96                 self.flag = False
  97
  98         def __getattr__(self, attr):
  99                 return getattr(self._face, attr)
 100
 101         def __cmp__(self, other):
 102                 if other is None:
 103                         return 1
 104                 return cmp(self.index, other.index)
 105
 106         def pivot_vertex(self, v):
 107                 n = self.vertices.index(v)
 108                 return [(n+i)%len(self.vertices) for i in range(len(self.vertices))]
 109
 110         def pivot_vertices(self, *vt):
 111                 flags = [(v in vt) for v in self.vertices]
 112                 l = len(self.vertices)
 113                 for i in range(l):
 114                         if flags[i] and not flags[(i+l-1)%l]:
 115                                 return self.vertices[i:]+self.vertices[:i]
 116
 117         def get_edge(self, v1, v2):
 118                 key = make_edge_key(v1.index, v2.index)
 119                 for e in self.edges:
 120                         if e.key==key:
 121                                 return e
 122                 raise KeyError("No edge %s"%(key,))
 123
 124         def other_edge(self, e, v):
 125                 for d in self.edges:
 126                         if d!=e and v in d.vertices:
 127                                 return d
 128
 129         def get_neighbors(self):
 130                 neighbors = [e.other_face(self) for e in self.edges]
 131                 return list(filter(bool, neighbors))
 132
 133
 134 class Line:
 135         def __init__(self, e):
 136                 self.edge = e
 137                 self.vertices = e.vertices[:]
 138                 self.flag = False
 139
 140
 141 class UvLayer:
 142         def __init__(self, arg):
 143                 if type(arg)==str:
 144                         self._layer = None
 145                         self.name = arg
 146                         self.uvs = []
 147                 else:
 148                         self._layer = arg
 149                         self.name = arg.name
 150                         self.uvs = [d.uv for d in self.data]
 151
 152                 self.unit = None
 153                 self.hidden = False
 154
 155                 dot = self.name.find('.')
 156                 if dot>=0:
 157                         ext = self.name[dot:]
 158                         if ext.startswith(".unit") and ext[5:].isdigit():
 159                                 self.unit = int(ext[5:])
 160                         elif ext==".hidden":
 161                                 self.hidden = True
 162
 163         def __getattr__(self, attr):
 164                 return getattr(self._layer, attr)
 165
 166
 167 class Mesh:
 168         def __init__(self, mesh):
 169                 self._mesh = mesh
 170                 self.name = mesh.name
 171
 172                 self.winding_test = mesh.winding_test
 173                 self.tbn_vecs = mesh.tbn_vecs
 174                 self.vertex_groups = mesh.vertex_groups
 175
 176                 # Clone basic data
 177                 self.vertices = [Vertex(v) for v in mesh.vertices]
 178                 for v in self.vertices:
 179                         v.groups = [VertexGroup(g) for g in v.groups]
 180
 181                 self.faces = [Face(f) for f in mesh.polygons]
 182                 self.edges = [Edge(e) for e in mesh.edges]
 183                 self.loops = mesh.loops[:]
 184                 self.materials = mesh.materials[:]
 185
 186                 # Clone only the desired UV layers
 187                 if self.use_uv=='NONE' or not mesh.uv_layers:
 188                         self.uv_layers = []
 189                 else:
 190                         self.uv_layers = [UvLayer(u) for u in mesh.uv_layers]
 191                         self.uv_layers = sorted([u for u in self.uv_layers if not u.hidden], key=(lambda u: (u.unit or 1000, u.name)))
 192
 193                         if self.use_uv=='UNIT0':
 194                                 self.uv_layers = [self.uv_layers[0]]
 195
 196                         # Assign texture unit numbers to UV layers that lack one
 197                         next_unit = max((u.unit+1 for u in self.uv_layers if u.unit is not None), default=0)
 198                         for u in self.uv_layers:
 199                                 if not u.unit:
 200                                         u.unit = next_unit
 201                                         next_unit += 1
 202
 203                 # Rewrite links between elements to point to cloned data, or create links
 204                 # where they don't exist
 205                 edge_map = {e.key: e for e in self.edges}
 206                 for f in self.faces:
 207                         if len(f.vertices)>4:
 208                                 raise ValueError("Ngons are not supported")
 209
 210                         f.vertices = [self.vertices[i] for i in f.vertices]
 211                         for v in f.vertices:
 212                                 v.faces.append(f)
 213
 214                         for k in f.edge_keys:
 215                                 e = edge_map[k]
 216                                 e.faces.append(f)
 217                                 f.edges.append(e)
 218
 219                 for e in self.edges:
 220                         e.vertices = [self.vertices[i] for i in e.vertices]
 221                         for v in e.vertices:
 222                                 v.edges.append(e)
 223
 224                 # Store loose edges as lines
 225                 if self.use_lines:
 226                         self.lines = [Line(e) for e in self.edges if not e.faces]
 227                 else:
 228                         self.lines = []
 229
 230                 self.vertex_sequence = []
 231
 232         def __getattr__(self, attr):
 233                 return getattr(self._mesh, attr)
 234
 235         def transform(self, matrix):
 236                 for v in self.vertices:
 237                         v.co = matrix*v.co
 238
 239         def splice(self, other):
 240                 if len(self.uv_layers)!=len(other.uv_layers):
 241                         raise ValueError("Meshes have incompatible UV layers")
 242                 for i, u in enumerate(self.uv_layers):
 243                         if u.name!=other.uv_layers[i].name:
 244                                 raise ValueError("Meshes have incompatible UV layers")
 245
 246                 # Merge materials and form a lookup from source material indices to the
 247                 # merged material list
 248                 material_map = []
 249                 for m in other.materials:
 250                         if m in self.materials:
 251                                 material_map.append(self.materials.index(m))
 252                         else:
 253                                 material_map.append(len(self.materials))
 254                                 self.materials.append(m)
 255
 256                 # Append data and adjust indices where necessary.  Since the data is
 257                 # spliced from the source mesh, rebuilding references is not necessary.
 258                 for i, u in enumerate(self.uv_layers):
 259                         u.uvs += other.uv_layers[i].uvs
 260
 261                 offset = len(self.vertices)
 262                 self.vertices += other.vertices
 263                 for v in self.vertices[offset:]:
 264                         v.index += offset
 265
 266                 loop_offset = len(self.loops)
 267                 self.loops += other.loops
 268
 269                 offset = len(self.faces)
 270                 self.faces += other.faces
 271                 for f in self.faces[offset:]:
 272                         f.index += offset
 273                         f.loop_start += loop_offset
 274                         f.loop_indices = range(f.loop_start, f.loop_start+f.loop_total)
 275                         if other.materials:
 276                                 f.material_index = material_map[f.material_index]
 277
 278                 offset = len(self.edges)
 279                 self.edges += other.edges
 280                 for e in self.edges[offset:]:
 281                         e.index += offset
 282                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 283
 284                 self.lines += other.lines
 285
 286         def prepare_triangles(self, progress):
 287                 face_count = len(self.faces)
 288                 for i in range(face_count):
 289                         f = self.faces[i]
 290                         nverts = len(f.vertices)
 291                         if nverts==3:
 292                                 continue
 293
 294                         # Calculate normals at each vertex of the face
 295                         edge_vecs = []
 296                         for j in range(nverts):
 297                                 edge_vecs.append(f.vertices[(j+1)%nverts].co-f.vertices[j].co)
 298
 299                         normals = []
 300                         for j in range(nverts):
 301                                 normals.append(edge_vecs[j-1].cross(edge_vecs[j]).normalized())
 302
 303                         # Check which diagonal results in a flatter triangulation
 304                         flatness1 = normals[0].dot(normals[2])
 305                         flatness2 = normals[1].dot(normals[3])
 306                         cut_index = 1 if flatness1>flatness2 else 0
 307
 308                         nf = Face(f)
 309                         nf.index = len(self.faces)
 310                         self.faces.append(nf)
 311
 312                         ne = Edge(None)
 313                         ne.index = len(self.edges)
 314                         self.edges.append(ne)
 315
 316                         nf.vertices = [f.vertices[cut_index], f.vertices[2], f.vertices[3]]
 317                         nf.loop_indices = [f.loop_indices[cut_index], f.loop_indices[2], f.loop_indices[3]]
 318                         for v in nf.vertices:
 319                                 v.faces.append(nf)
 320
 321                         ne.vertices = [f.vertices[cut_index], f.vertices[2+cut_index]]
 322                         for v in ne.vertices:
 323                                 v.edges.append(ne)
 324                         ne.key = make_edge_key(ne.vertices[0].index, ne.vertices[1].index)
 325                         ne.smooth = True
 326
 327                         f.vertices[3-cut_index].faces.remove(f)
 328                         del f.vertices[3-cut_index]
 329                         f.loop_indices = [f.loop_indices[0], f.loop_indices[1], f.loop_indices[2+cut_index]]
 330
 331                         ne.faces = [f, nf]
 332                         if cut_index==0:
 333                                 nf.edges = [ne, f.edges[2], f.edges[3]]
 334                                 f.edges = [f.edges[0], f.edges[1], ne]
 335                         else:
 336                                 nf.edges = [f.edges[1], f.edges[2], ne]
 337                                 f.edges = [f.edges[0], ne, f.edges[3]]
 338                         for e in nf.edges:
 339                                 if e!=ne:
 340                                         e.faces.remove(f)
 341                                         e.faces.append(nf)
 342
 343                         f.normal = normals[1-cut_index]
 344                         nf.normal = normals[3-cut_index]
 345
 346                         progress.set_progress(i/face_count)
 347
 348         def prepare_smoothing(self, progress):
 349                 smooth_limit = -1
 350                 if self.smoothing=='NONE':
 351                         for f in self.faces:
 352                                 f.use_smooth = False
 353
 354                         smooth_limit = 1
 355                 elif self.use_auto_smooth:
 356                         smooth_limit = math.cos(self.auto_smooth_angle)
 357
 358                 for e in self.edges:
 359                         e.check_smooth(smooth_limit)
 360
 361                 progress.push_task("Sharp edges", 0.0, 0.7)
 362                 self.split_vertices(self.find_smooth_group, progress)
 363
 364                 if self.smoothing!='BLENDER':
 365                         progress.set_task("Updating normals", 0.7, 1.0)
 366                         self.compute_normals(progress)
 367
 368                 progress.pop_task()
 369
 370         def prepare_vertex_groups(self, obj):
 371                 for v in self.vertices:
 372                         if v.groups:
 373                                 weight_sum = sum(g.weight for g in v.groups)
 374                                 v.groups = sorted(v.groups, key=(lambda g: g.weight), reverse=True)[:self.max_groups_per_vertex]
 375                                 weight_scale = weight_sum/sum(g.weight for g in v.groups)
 376                                 for g in v.groups:
 377                                         g.weight *= weight_scale
 378
 379                 if obj.parent and obj.parent.type=="ARMATURE":
 380                         armature = obj.parent.data
 381                         bone_indices = {b.name: i for i, b in enumerate(armature.bones)}
 382                         group_index_map = {i: i for i in range(len(obj.vertex_groups))}
 383                         for g in first_obj.vertex_groups:
 384                                 if g.name in bone_indices:
 385                                         group_index_map[g.index] = bone_indices[g.name]
 386
 387                         for v in self.vertices:
 388                                 for g in v.groups:
 389                                         g.group = group_index_map[g.group]
 390
 391         def prepare_uv(self, progress):
 392                 # Form a list of UV layers referenced by materials with the array atlas
 393                 # property set
 394                 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']
 395                 array_uv_layers = [u for u in self.uv_layers if u.name in array_uv_layers]
 396
 397                 if array_uv_layers:
 398                         for f in self.faces:
 399                                 layer = 0
 400                                 if f.material_index<len(self.materials):
 401                                         mat = self.materials[f.material_index]
 402                                         if mat and mat.array_atlas:
 403                                                 layer = mat.array_layer
 404
 405                                 for l in array_uv_layers:
 406                                         for i in f.loop_indices:
 407                                                 l.uvs[i] = mathutils.Vector((*l.uvs[i], layer))
 408
 409                 # Copy UVs from layers to faces
 410                 for f in self.faces:
 411                         for u in self.uv_layers:
 412                                 f.uvs.append([u.uvs[i] for i in f.loop_indices])
 413
 414                 prog_count = len(self.uv_layers)
 415                 prog_step = 0
 416
 417                 # Split by the UV layer used for TBN vectors first so connectivity
 418                 # remains intact for TBN vector computation
 419                 tbn_layer_index = -1
 420                 if self.tbn_vecs:
 421                         uv_names = [u.name for u in self.uv_layers]
 422                         if self.tbn_uvtex in uv_names:
 423                                 prog_count += 1
 424                                 tbn_layer_index = uv_names.index(self.tbn_uvtex)
 425                                 progress.push_task_slice("Computing TBN", 0, prog_count)
 426                                 self.split_vertices(self.find_uv_group, progress, tbn_layer_index)
 427                                 progress.set_task_slice(self.tbn_uvtex, 1, prog_count)
 428                                 self.compute_tbn(tbn_layer_index, progress)
 429                                 progress.pop_task()
 430                                 prog_step = 2
 431
 432                 # Split by the remaining UV layers
 433                 for i, u in enumerate(self.uv_layers):
 434                         if i==tbn_layer_index:
 435                                 continue
 436
 437                         progress.push_task_slice(u.name, prog_step, prog_count)
 438                         self.split_vertices(self.find_uv_group, progress, i)
 439                         progress.pop_task()
 440                         prog_step += 1
 441
 442                 # Copy UVs from faces to vertices
 443                 for v in self.vertices:
 444                         if v.faces:
 445                                 # All faces still connected to the vertex have the same UV value
 446                                 f = v.faces[0]
 447                                 i = f.vertices.index(v)
 448                                 v.uvs = [u[i] for u in f.uvs]
 449                         else:
 450                                 v.uvs = [(0.0, 0.0)]*len(self.uv_layers)
 451
 452         def split_vertices(self, find_group_func, progress, *args):
 453                 vertex_count = len(self.vertices)
 454                 for i in range(vertex_count):
 455                         v = self.vertices[i]
 456                         for f in v.faces:
 457                                 f.flag = False
 458
 459                         # Find all groups of faces on this vertex
 460                         groups = []
 461                         for f in v.faces:
 462                                 if not f.flag:
 463                                         groups.append(find_group_func(v, f, *args))
 464
 465                         # Give groups after the first separate copies of the vertex
 466                         for g in groups[1:]:
 467                                 nv = Vertex(v)
 468                                 nv.index = len(self.vertices)
 469                                 self.vertices.append(nv)
 470
 471                                 for e in v.edges:
 472                                         e_faces_in_g = [f for f in e.faces if f in g]
 473                                         if not e_faces_in_g:
 474                                                 continue
 475
 476                                         if len(e_faces_in_g)<len(e.faces):
 477                                                 # Create a copy of an edge at the boundary of the group
 478                                                 ne = Edge(e)
 479                                                 ne.index = len(self.edges)
 480                                                 self.edges.append(ne)
 481
 482                                                 ne.other_vertex(v).edges.append(ne)
 483
 484                                                 for f in e_faces_in_g:
 485                                                         e.faces.remove(f)
 486                                                         f.edges[f.edges.index(e)] = ne
 487                                                         ne.faces.append(f)
 488
 489                                                 e = ne
 490
 491                                         e.vertices[e.vertices.index(v)] = nv
 492                                         nv.edges.append(e)
 493
 494                                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 495
 496                                 # Filter out any edges that were removed from the original vertex
 497                                 v.edges = [e for e in v.edges if v in e.vertices]
 498
 499                                 for f in g:
 500                                         v.faces.remove(f)
 501                                         f.vertices[f.vertices.index(v)] = nv
 502                                         nv.faces.append(f)
 503
 504                         progress.set_progress(i/vertex_count)
 505
 506         def find_smooth_group(self, vertex, face):
 507                 face.flag = True
 508
 509                 edges = [e for e in face.edges if vertex in e.vertices]
 510
 511                 group = [face]
 512                 for e in edges:
 513                         f = face
 514                         while e.smooth:
 515                                 f = e.other_face(f)
 516                                 if not f or f.flag:
 517                                         break
 518
 519                                 f.flag = True
 520                                 group.append(f)
 521                                 e = f.other_edge(e, vertex)
 522
 523                 return group
 524
 525         def find_uv_group(self, vertex, face, index):
 526                 uv = face.uvs[index][face.vertices.index(vertex)]
 527                 face.flag = True
 528
 529                 group = [face]
 530                 for f in vertex.faces:
 531                         if not f.flag and f.uvs[index][f.vertices.index(vertex)]==uv:
 532                                 f.flag = True
 533                                 group.append(f)
 534
 535                 return group
 536
 537         def compute_normals(self, progress):
 538                 for i, v in enumerate(self.vertices):
 539                         v.normal = mathutils.Vector()
 540                         for f in v.faces:
 541                                 fv = f.pivot_vertices(v)
 542                                 edge1 = fv[1].co-fv[0].co
 543                                 edge2 = fv[-1].co-fv[0].co
 544                                 if edge1.length and edge2.length:
 545                                         # Use the angle between edges as a weighting factor.  This gives
 546                                         # more consistent normals on bends with an inequal number of
 547                                         # faces on each side.
 548                                         v.normal += f.normal*edge1.angle(edge2)
 549
 550                         if v.normal.length:
 551                                 v.normal.normalize()
 552                         else:
 553                                 v.normal = mathutils.Vector((0, 0, 1))
 554
 555                         progress.set_progress(i/len(self.vertices))
 556
 557         def compute_tbn(self, index, progress):
 558                 # This function is called at an early stage during UV preparation when
 559                 # face UVs are not available yet
 560                 layer_uvs = self.uv_layers[index].uvs
 561
 562                 for i, v in enumerate(self.vertices):
 563                         v.tan = mathutils.Vector()
 564                         v.bino = mathutils.Vector()
 565                         for f in v.faces:
 566                                 vi = f.pivot_vertex(v)
 567                                 uv0 = layer_uvs[f.loop_indices[vi[0]]]
 568                                 uv1 = layer_uvs[f.loop_indices[vi[1]]]
 569                                 uv2 = layer_uvs[f.loop_indices[vi[-1]]]
 570                                 du1 = uv1[0]-uv0[0]
 571                                 du2 = uv2[0]-uv0[0]
 572                                 dv1 = uv1[1]-uv0[1]
 573                                 dv2 = uv2[1]-uv0[1]
 574                                 edge1 = f.vertices[vi[1]].co-f.vertices[vi[0]].co
 575                                 edge2 = f.vertices[vi[-1]].co-f.vertices[vi[0]].co
 576                                 div = (du1*dv2-du2*dv1)
 577                                 if div:
 578                                         mul = edge1.angle(edge2)/div
 579                                         v.tan += (edge1*dv2-edge2*dv1)*mul
 580                                         v.bino += (edge2*du1-edge1*du2)*mul
 581
 582                         if v.tan.length:
 583                                 v.tan.normalize()
 584                         if v.bino.length:
 585                                 v.bino.normalize()
 586
 587                         progress.set_progress(i/len(self.vertices))
 588
 589         def prepare_sequence(self, progress):
 590                 progress.push_task("Reordering faces", 0.0, 0.5)
 591                 self.reorder_faces(progress)
 592
 593                 progress.set_task("Building sequence", 0.5, 1.0)
 594                 sequence = None
 595                 for i, f in enumerate(self.faces):
 596                         if sequence:
 597                                 if len(sequence)==3:
 598                                         # Rotate the first three vertices so that the new face can be added
 599                                         if sequence[0] in f.vertices and sequence[1] not in f.vertices:
 600                                                 sequence.append(sequence[0])
 601                                                 del sequence[0]
 602                                         elif sequence[2] not in f.vertices and sequence[1] in f.vertices:
 603                                                 sequence.insert(0, sequence[-1])
 604                                                 del sequence[-1]
 605
 606                                 if sequence[-1] not in f.vertices:
 607                                         sequence = None
 608                                 else:
 609                                         to_add = [v for v in f.vertices if v!=sequence[-1] and v!=sequence[-2]]
 610                                         if len(to_add)==2:
 611                                                 if (f.vertices[1]==sequence[-1]) != (len(sequence)%2==1):
 612                                                         to_add.reverse()
 613                                                 sequence.append(sequence[-1])
 614                                         sequence += to_add
 615
 616                         if not sequence:
 617                                 sequence = f.vertices[:]
 618                                 self.vertex_sequence.append(sequence)
 619
 620                         progress.set_progress(i/len(self.faces))
 621
 622                 progress.pop_task()
 623
 624                 self.reorder_vertices()
 625
 626         def reorder_faces(self, progress):
 627                 # Tom Forsyth's vertex cache optimization algorithm
 628                 # http://eelpi.gotdns.org/papers/fast_vert_cache_opt.html
 629
 630                 for f in self.faces:
 631                         f.flag = False
 632
 633                 last_triangle_score = 0.75
 634                 cache_decay_power = 1.5
 635                 valence_boost_scale = 2.0
 636                 valence_boost_power = -0.5
 637
 638                 max_cache_size = 32
 639                 cached_vertices = []
 640
 641                 # Keep track of the score and number of unused faces for each vertex
 642                 vertex_info = [[0, len(v.faces)] for v in self.vertices]
 643                 for vi in vertex_info:
 644                         vi[0] = valence_boost_scale*(vi[1]**valence_boost_power)
 645
 646                 face = None
 647                 reordered_faces = []
 648
 649                 n_processed = 0
 650                 while 1:
 651                         if not face:
 652                                 # Previous iteration gave no candidate for best face (or this is
 653                                 # the first iteration).  Scan all faces for the highest score.
 654                                 best_score = 0
 655                                 for f in self.faces:
 656                                         if f.flag:
 657                                                 continue
 658
 659                                         score = sum(vertex_info[v.index][0] for v in f.vertices)
 660                                         if score>best_score:
 661                                                 best_score = score
 662                                                 face = f
 663
 664                         if not face:
 665                                 break
 666
 667                         reordered_faces.append(face)
 668                         face.flag = True
 669
 670                         for v in face.vertices:
 671                                 vertex_info[v.index][1] -= 1
 672
 673                                 # Shuffle the vertex into the front of the cache
 674                                 if v in cached_vertices:
 675                                         cached_vertices.remove(v)
 676                                 cached_vertices.insert(0, v)
 677
 678                         # Update scores for all vertices in the cache
 679                         for i, v in enumerate(cached_vertices):
 680                                 score = 0
 681                                 if i<3:
 682                                         score += last_triangle_score
 683                                 elif i<max_cache_size:
 684                                         score += (1-(i-3)/(max_cache_size-3))**cache_decay_power
 685                                 if vertex_info[v.index][1]:
 686                                         score += valence_boost_scale*(vertex_info[v.index][1]**valence_boost_power)
 687                                 vertex_info[v.index][0] = score
 688
 689                         face = None
 690                         best_score = 0
 691                         for v in cached_vertices:
 692                                 for f in v.faces:
 693                                         if not f.flag:
 694                                                 score = sum(vertex_info[fv.index][0] for fv in f.vertices)
 695                                                 if score>best_score:
 696                                                         best_score = score
 697                                                         face = f
 698
 699                         del cached_vertices[max_cache_size:]
 700
 701                         n_processed += 1
 702                         progress.set_progress(n_processed/len(self.faces))
 703
 704                 self.faces = reordered_faces
 705                 for i, f in enumerate(self.faces):
 706                         f.index = i
 707
 708         def reorder_vertices(self):
 709                 for v in self.vertices:
 710                         v.index = -1
 711
 712                 reordered_vertices = []
 713                 for s in self.vertex_sequence:
 714                         for v in s:
 715                                 if v.index<0:
 716                                         v.index = len(reordered_vertices)
 717                                         reordered_vertices.append(v)
 718
 719                 self.vertices = reordered_vertices
 720
 721                 for e in self.edges:
 722                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 723
 724         def drop_references(self):
 725                 for v in self.vertices:
 726                         v._vertex = None
 727                         for g in v.groups:
 728                                 g._group = None
 729                 for e in self.edges:
 730                         e._edge = None
 731                 for f in self.faces:
 732                         f._face = None
 733                 for u in self.uv_layers:
 734                         u._layer = None
 735                 self._mesh = None
 736
 737
 738 def create_mesh_from_object(context, obj, progress):
 739         if obj.type!="MESH":
 740                 raise Exception("Object is not a mesh")
 741
 742         progress.push_task("Preparing mesh", 0.0, 0.2)
 743
 744         objs = [(obj, mathutils.Matrix())]
 745         i = 0
 746         while i<len(objs):
 747                 o, m = objs[i]
 748                 i += 1
 749                 for c in o.children:
 750                         if c.type=="MESH" and c.compound:
 751                                 objs.append((c, m*c.matrix_local))
 752
 753         mesh = None
 754         bmeshes = []
 755         for o, m in objs:
 756                 bmesh = o.to_mesh(context.scene, True, "PREVIEW")
 757                 bmeshes.append(bmesh)
 758
 759                 # Object.to_mesh does not copy custom properties
 760                 bmesh.winding_test = o.data.winding_test
 761                 bmesh.smoothing = o.data.smoothing
 762                 bmesh.use_lines = o.data.use_lines
 763                 bmesh.vertex_groups = o.data.vertex_groups
 764                 bmesh.max_groups_per_vertex = o.data.max_groups_per_vertex
 765                 bmesh.use_uv = o.data.use_uv
 766                 bmesh.tbn_vecs = o.data.tbn_vecs
 767                 bmesh.tbn_uvtex = o.data.tbn_uvtex
 768
 769                 me = Mesh(bmesh)
 770                 me.transform(m)
 771
 772                 if mesh:
 773                         mesh.splice(me)
 774                 else:
 775                         mesh = me
 776
 777         mesh.name = obj.data.name
 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         # Discard the temporary Blender meshes after making sure there's no
 791         # references to the data
 792         mesh.drop_references()
 793         for m in bmeshes:
 794                 bpy.data.meshes.remove(m)
 795
 796         progress.pop_task()
 797
 798         return mesh