blender/io_mspgl/mesh.py

   1 import math
   2 import mathutils
   3 import itertools
   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.smooth = edge.smooth
  12                 else:
  13                         self.smooth = False
  14                 if edge:
  15                         self.vertices = edge.vertices[:]
  16                         self.key = edge.key
  17                 else:
  18                         self.vertices = []
  19                         self.key = None
  20                 self.faces = []
  21
  22         def check_smooth(self, limit):
  23                 if len(self.faces)!=2:
  24                         return
  25
  26                 d = self.faces[0].normal.dot(self.faces[1].normal)
  27                 self.smooth = ((d>limit and self.faces[0].use_smooth and self.faces[1].use_smooth) or d>0.99995)
  28
  29         def other_face(self, f):
  30                 if f.index==self.faces[0].index:
  31                         if len(self.faces)>=2:
  32                                 return self.faces[1]
  33                         else:
  34                                 return None
  35                 else:
  36                         return self.faces[0]
  37
  38         def other_vertex(self, v):
  39                 if v.index==self.vertices[0].index:
  40                         return self.vertices[1]
  41                 else:
  42                         return self.vertices[0]
  43
  44
  45 class Vertex:
  46         def __init__(self, vertex):
  47                 if vertex.__class__==Vertex:
  48                         self.uvs = vertex.uvs[:]
  49                         self.tan = vertex.tan
  50                 else:
  51                         self.uvs = []
  52                         self.tan = None
  53                 self.index = vertex.index
  54                 self.co = mathutils.Vector(vertex.co)
  55                 self.normal = mathutils.Vector(vertex.normal)
  56                 self.color = None
  57                 self.flag = False
  58                 self.edges = []
  59                 self.faces = []
  60                 self.groups = vertex.groups[:]
  61
  62         def __cmp__(self, other):
  63                 if other is None:
  64                         return 1
  65                 return cmp(self.index, other.index)
  66
  67
  68 class VertexGroup:
  69         def __init__(self, *args):
  70                 if len(args)==2:
  71                         self.group = args[0]
  72                         self.weight = args[1]
  73                 elif len(args)==1 and args[0]:
  74                         self.group = group.group
  75                         self.weight = group.weight
  76                 else:
  77                         self.group = 0
  78                         self.weight = 0.0
  79
  80
  81 class Batch:
  82         def __init__(self, pt):
  83                 self.primitive_type = pt
  84                 self.patch_size = 0
  85                 self.vertices = []
  86
  87
  88 class Face:
  89         def __init__(self, face):
  90                 self.index = face.index
  91                 self.edges = []
  92                 self.edge_keys = face.edge_keys
  93                 self.vertices = face.vertices[:]
  94                 self.loop_indices = face.loop_indices
  95                 self.normal = face.normal
  96                 self.use_smooth = face.use_smooth
  97                 self.material_index = face.material_index
  98                 self.splat_mask = 0
  99                 self.flag = False
 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 get_loop_index(self, v):
 111                 return self.loop_indices[self.vertices.index(v)]
 112
 113         def get_edge(self, v1, v2):
 114                 key = make_edge_key(v1.index, v2.index)
 115                 for e in self.edges:
 116                         if e.key==key:
 117                                 return e
 118                 raise KeyError("No edge %s"%(key,))
 119
 120         def other_edge(self, e, v):
 121                 for d in self.edges:
 122                         if d!=e and v in d.vertices:
 123                                 return d
 124
 125         def get_neighbors(self):
 126                 neighbors = [e.other_face(self) for e in self.edges]
 127                 return list(filter(bool, neighbors))
 128
 129
 130 class Line:
 131         def __init__(self, e):
 132                 self.edge = e
 133                 self.vertices = e.vertices[:]
 134                 self.flag = False
 135
 136
 137 class UvLayer:
 138         def __init__(self, arg):
 139                 if type(arg)==str:
 140                         self.name = arg
 141                         self.uvs = []
 142                 else:
 143                         self.name = arg.name
 144                         self.uvs = [mathutils.Vector(d.uv) for d in arg.data]
 145
 146                 self.unit = None
 147                 self.hidden = False
 148
 149                 dot = self.name.find('.')
 150                 if dot>=0:
 151                         ext = self.name[dot:]
 152                         if ext.startswith(".unit") and ext[5:].isdigit():
 153                                 self.unit = int(ext[5:])
 154                         elif ext==".hidden":
 155                                 self.hidden = True
 156
 157
 158 class ColorLayer:
 159         def __init__(self, l):
 160                 self.name = l.name
 161                 self.colors = [c.color[:] for c in l.data]
 162
 163
 164 class Mesh:
 165         def __init__(self, mesh):
 166                 self.name = mesh.name
 167
 168                 self.smoothing = mesh.smoothing
 169                 self.use_uv = mesh.use_uv
 170                 self.tangent_uvtex = mesh.tangent_uvtex
 171                 self.use_strips = mesh.use_strips
 172                 self.use_patches = mesh.use_patches
 173                 self.use_lines = mesh.use_lines
 174                 self.vertex_groups = mesh.vertex_groups
 175
 176                 # Clone basic data
 177                 self.vertices = [Vertex(v) for v in mesh.vertices]
 178                 if self.vertex_groups:
 179                         for v in self.vertices:
 180                                 v.groups = [VertexGroup(g) for g in v.groups]
 181
 182                 self.faces = [Face(f) for f in mesh.polygons]
 183                 self.edges = [Edge(e) for e in mesh.edges]
 184                 self.loops = mesh.loops[:]
 185                 self.materials = mesh.materials[:]
 186
 187                 self.use_auto_smooth = mesh.use_auto_smooth
 188                 self.auto_smooth_angle = mesh.auto_smooth_angle
 189                 self.max_groups_per_vertex = mesh.max_groups_per_vertex
 190
 191                 # Check some material properties
 192                 from .material import Material
 193                 has_normal_maps = False
 194                 splat_material = None
 195                 for m in self.materials:
 196                         mat = Material(m)
 197                         for p in itertools.chain(mat.properties, *(s.properties for s in mat.sub_materials)):
 198                                 if p.tex_keyword=="normal_map" and p.texture:
 199                                         has_normal_maps = True
 200                                         break
 201                         if mat.type=="splat":
 202                                 splat_material = mat
 203
 204                 # Clone only the desired UV layers
 205                 if mesh.use_uv=='NONE' or not mesh.uv_layers:
 206                         self.uv_layers = []
 207                 else:
 208                         self.uv_layers = [UvLayer(u) for u in mesh.uv_layers if u.data]
 209
 210                         # Assign texture unit numbers to UV layers that lack one
 211                         missing_unit = [u for u in self.uv_layers if u.unit is None]
 212                         if missing_unit:
 213                                 missing_unit = sorted(missing_unit, key=(lambda u: u.name))
 214                                 used_units = [u.unit for u in self.uv_layers if u.unit is not None]
 215                                 for u, n in zip(missing_unit, (i for i in itertools.count() if i not in used_units)):
 216                                         u.unit = n
 217
 218                         self.uv_layers = sorted(self.uv_layers, key=(lambda u: u.unit))
 219
 220                         if mesh.use_uv=='UNIT0' and self.uv_layers:
 221                                 self.uv_layers = [self.uv_layers[0]]
 222                                 if self.uv_layers[0].unit!=0:
 223                                         self.uv_layers = []
 224
 225                 self.colors = None
 226                 if mesh.vertex_colors and not splat_material:
 227                         self.colors = ColorLayer(mesh.vertex_colors[0])
 228
 229                 # Rewrite links between elements to point to cloned data, or create links
 230                 # where they don't exist
 231                 edge_map = {e.key: e for e in self.edges}
 232                 for f in self.faces:
 233                         if len(f.vertices)>4 and not mesh.use.patches:
 234                                 raise ValueError("Unsupported face on mesh {}: N-gon".format(self.name))
 235
 236                         f.vertices = [self.vertices[i] for i in f.vertices]
 237                         for v in f.vertices:
 238                                 v.faces.append(f)
 239
 240                         for k in f.edge_keys:
 241                                 e = edge_map[k]
 242                                 e.faces.append(f)
 243                                 f.edges.append(e)
 244
 245                 for e in self.edges:
 246                         e.vertices = [self.vertices[i] for i in e.vertices]
 247                         for v in e.vertices:
 248                                 v.edges.append(e)
 249
 250                 # Store loose edges as lines
 251                 if mesh.use_lines and not mesh.use_patches:
 252                         self.lines = [Line(e) for e in self.edges if not e.faces]
 253                 else:
 254                         self.lines = []
 255
 256                 # Check if tangent vectors are needed
 257                 if mesh.tangent_vecs=='NO':
 258                         self.tangent_vecs = False
 259                 elif mesh.tangent_vecs=='YES':
 260                         self.tangent_vecs = True
 261                 elif mesh.tangent_vecs=='AUTO':
 262                         self.tangent_vecs = has_normal_maps
 263
 264                 # Collect splat weight sources if needed
 265                 self.splat_layers = []
 266                 self.splat_sources = []
 267                 if splat_material:
 268                         names = {s.weight_source[0] for s in splat_material.sub_materials}
 269                         self.splat_layers = [ColorLayer(l) for l in mesh.vertex_colors if l.name in names]
 270
 271                         layers_by_name = {l.name:l for l in self.splat_layers}
 272                         for s in splat_material.sub_materials:
 273                                 if s.weight_source[0] is None:
 274                                         self.splat_sources.append((None, None))
 275                                 else:
 276                                         self.splat_sources.append((layers_by_name[s.weight_source[0]], "RGBA".index(s.weight_source[1])))
 277
 278                         self.vertex_groups = True
 279                         self.max_groups_per_vertex = 3
 280
 281                 self.batches = []
 282
 283         def transform(self, matrix):
 284                 for v in self.vertices:
 285                         v.co = matrix@v.co
 286
 287         def splice(self, other):
 288                 if len(self.uv_layers)!=len(other.uv_layers):
 289                         raise ValueError("Meshes {} and {} have incompatible UV layers".format(self.name, other.name))
 290                 for i, u in enumerate(self.uv_layers):
 291                         if u.name!=other.uv_layers[i].name:
 292                                 raise ValueError("Meshes {} and {} have incompatible UV layers".format(self.name, other.name))
 293
 294                 # Merge materials and form a lookup from source material indices to the
 295                 # merged material list
 296                 material_lookup = []
 297                 for m in other.materials:
 298                         if m in self.materials:
 299                                 material_lookup.append(self.materials.index(m))
 300                         else:
 301                                 material_lookup.append(len(self.materials))
 302                                 self.materials.append(m)
 303
 304                 # Append data and adjust indices where necessary.  Since the data is
 305                 # spliced from the source mesh, rebuilding references is not necessary.
 306                 for i, u in enumerate(self.uv_layers):
 307                         u.uvs += other.uv_layers[i].uvs
 308
 309                 if self.colors:
 310                         if other.colors:
 311                                 self.colors.colors += other.colors.colors
 312                         else:
 313                                 self.colors.colors += [(1.0, 1.0, 1.0, 1.0)]*len(other.loops)
 314                 elif other.colors:
 315                         self.colors = ColorLayer(other.colors.name)
 316                         self.colors.colors = [(1.0, 1.0, 1.0, 1.0)]*len(self.loops)+other.colors.colors
 317
 318                 offset = len(self.vertices)
 319                 self.vertices += other.vertices
 320                 for v in self.vertices[offset:]:
 321                         v.index += offset
 322
 323                 loop_offset = len(self.loops)
 324                 self.loops += other.loops
 325
 326                 offset = len(self.faces)
 327                 self.faces += other.faces
 328                 for f in self.faces[offset:]:
 329                         f.index += offset
 330                         f.loop_indices = range(f.loop_indices.start+offset, f.loop_indices.stop+offset)
 331                         if other.materials:
 332                                 f.material_index = material_lookup[f.material_index]
 333
 334                 offset = len(self.edges)
 335                 self.edges += other.edges
 336                 for e in self.edges[offset:]:
 337                         e.index += offset
 338                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 339
 340                 self.lines += other.lines
 341
 342         def prepare_triangles(self, task):
 343                 if self.use_patches:
 344                         return
 345
 346                 face_count = len(self.faces)
 347                 for i in range(face_count):
 348                         f = self.faces[i]
 349                         nverts = len(f.vertices)
 350                         if nverts==3:
 351                                 continue
 352
 353                         # Calculate normals at each vertex of the face
 354                         edge_vecs = []
 355                         for j in range(nverts):
 356                                 edge_vecs.append(f.vertices[(j+1)%nverts].co-f.vertices[j].co)
 357
 358                         normals = []
 359                         for j in range(nverts):
 360                                 normals.append(edge_vecs[j-1].cross(edge_vecs[j]).normalized())
 361
 362                         # Check which diagonal results in a flatter triangulation
 363                         flatness1 = normals[0].dot(normals[2])
 364                         flatness2 = normals[1].dot(normals[3])
 365                         cut_index = 1 if flatness1>flatness2 else 0
 366
 367                         nf = Face(f)
 368                         nf.index = len(self.faces)
 369                         self.faces.append(nf)
 370
 371                         ne = Edge(None)
 372                         ne.index = len(self.edges)
 373                         self.edges.append(ne)
 374
 375                         nf.vertices = [f.vertices[cut_index], f.vertices[2], f.vertices[3]]
 376                         nf.loop_indices = [f.loop_indices[cut_index], f.loop_indices[2], f.loop_indices[3]]
 377                         for v in nf.vertices:
 378                                 v.faces.append(nf)
 379
 380                         ne.vertices = [f.vertices[cut_index], f.vertices[2+cut_index]]
 381                         for v in ne.vertices:
 382                                 v.edges.append(ne)
 383                         ne.key = make_edge_key(ne.vertices[0].index, ne.vertices[1].index)
 384                         ne.smooth = True
 385
 386                         f.vertices[3-cut_index].faces.remove(f)
 387                         del f.vertices[3-cut_index]
 388                         f.loop_indices = [f.loop_indices[0], f.loop_indices[1], f.loop_indices[2+cut_index]]
 389
 390                         ne.faces = [f, nf]
 391                         if cut_index==0:
 392                                 nf.edges = [ne, f.edges[2], f.edges[3]]
 393                                 f.edges = [f.edges[0], f.edges[1], ne]
 394                         else:
 395                                 nf.edges = [f.edges[1], f.edges[2], ne]
 396                                 f.edges = [f.edges[0], ne, f.edges[3]]
 397                         for e in nf.edges:
 398                                 if e!=ne:
 399                                         e.faces.remove(f)
 400                                         e.faces.append(nf)
 401
 402                         f.normal = normals[1-cut_index]
 403                         nf.normal = normals[3-cut_index]
 404
 405                         task.set_progress(i/face_count)
 406
 407         def prepare_smoothing(self, task):
 408                 smooth_limit = -1
 409                 if self.smoothing=='NONE':
 410                         for f in self.faces:
 411                                 f.use_smooth = False
 412
 413                         smooth_limit = 1
 414                 elif self.use_auto_smooth:
 415                         smooth_limit = math.cos(self.auto_smooth_angle)
 416
 417                 for e in self.edges:
 418                         e.check_smooth(smooth_limit)
 419
 420                 subtask = task.task("Sharp edges", 0.7)
 421                 self.split_vertices(self.find_smooth_group, subtask)
 422
 423                 if self.smoothing!='BLENDER':
 424                         subtask = task.task("Updating normals", 1.0)
 425                         self.compute_normals(subtask)
 426
 427         def prepare_vertex_groups(self, obj):
 428                 if not self.vertex_groups:
 429                         return
 430
 431                 for v in self.vertices:
 432                         if v.groups:
 433                                 weight_sum = sum(g.weight for g in v.groups)
 434                                 v.groups = sorted(v.groups, key=(lambda g: g.weight), reverse=True)[:self.max_groups_per_vertex]
 435                                 weight_scale = weight_sum/sum(g.weight for g in v.groups)
 436                                 for g in v.groups:
 437                                         g.weight *= weight_scale
 438                         while len(v.groups)<self.max_groups_per_vertex:
 439                                 v.groups.append(VertexGroup(None))
 440
 441                 if obj.parent and obj.parent.type=="ARMATURE":
 442                         armature = obj.parent.data
 443                         bone_indices = {b.name: i for i, b in enumerate(armature.bones)}
 444                         group_index_map = {i: i for i in range(len(obj.vertex_groups))}
 445                         for g in first_obj.vertex_groups:
 446                                 if g.name in bone_indices:
 447                                         group_index_map[g.index] = bone_indices[g.name]
 448
 449                         for v in self.vertices:
 450                                 for g in v.groups:
 451                                         g.group = group_index_map[g.group]
 452
 453         def prepare_uv(self, task):
 454                 # Form a list of UV layers referenced by materials with the array atlas
 455                 # property set
 456                 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']
 457                 array_uv_layers = [u for u in self.uv_layers if u.name in array_uv_layers]
 458
 459                 if array_uv_layers:
 460                         for f in self.faces:
 461                                 layer = 0
 462                                 if f.material_index<len(self.materials):
 463                                         mat = self.materials[f.material_index]
 464                                         if mat and mat.array_atlas:
 465                                                 layer = mat.array_layer
 466
 467                                 for l in array_uv_layers:
 468                                         for i in f.loop_indices:
 469                                                 l.uvs[i] = mathutils.Vector((*l.uvs[i], layer))
 470
 471                 # Split by the UV layer used for tangent vectors first so connectivity
 472                 # remains intact for tangent vector computation
 473                 tangent_layer_index = -1
 474                 if self.tangent_vecs:
 475                         if self.tangent_uvtex:
 476                                 uv_names = [u.name for u in self.uv_layers]
 477                                 if self.tangent_uvtex in uv_names:
 478                                         tangent_layer_index = uv_names.index(self.tangent_uvtex)
 479                         elif self.uv_layers[0].unit==0:
 480                                 tangent_layer_index = 0
 481
 482                         if tangent_layer_index<0:
 483                                 raise Exception("Invalid configuration on mesh {}: No tangent UV layer".format(self.name))
 484
 485                 prog_count = len(self.uv_layers)
 486                 if tangent_layer_index>=0:
 487                         prog_count += 1
 488                 task.set_slices(prog_count)
 489
 490                 if tangent_layer_index>=0:
 491                         subtask = task.next_slice("Computing tangents")
 492                         self.split_vertices(self.find_uv_group, subtask, tangent_layer_index)
 493                         subtask = task.next_slice(self.tangent_uvtex)
 494                         self.compute_tangents(tangent_layer_index, subtask)
 495
 496                 # Split by the remaining UV layers
 497                 for i, u in enumerate(self.uv_layers):
 498                         if i==tangent_layer_index:
 499                                 continue
 500
 501                         subtask = task.next_slice(u.name)
 502                         self.split_vertices(self.find_uv_group, subtask, i)
 503
 504                 # Copy UVs from layers to vertices
 505                 for v in self.vertices:
 506                         if v.faces:
 507                                 # All faces still connected to the vertex have the same UV value
 508                                 f = v.faces[0]
 509                                 i = f.get_loop_index(v)
 510                                 v.uvs = [u.uvs[i] for u in self.uv_layers]
 511                         else:
 512                                 v.uvs = [(0.0, 0.0)]*len(self.uv_layers)
 513
 514         def prepare_colors(self, task):
 515                 if not self.colors:
 516                         return
 517
 518                 self.split_vertices(self.find_color_group, task)
 519
 520                 for v in self.vertices:
 521                         if v.faces:
 522                                 f = v.faces[0]
 523                                 v.color = self.colors.colors[f.get_loop_index(v)]
 524                         else:
 525                                 v.color = (1.0, 1.0, 1.0, 1.0)
 526
 527         def prepare_splat_weights(self, task):
 528                 if not self.splat_layers:
 529                         return
 530
 531                 splat_weights = []
 532                 remainder = None
 533                 for s in self.splat_sources:
 534                         if s[0] is None:
 535                                 splat_weights.append(remainder)
 536                         else:
 537                                 index = s[1]
 538                                 layer_values = [c[index] for c in s[0].colors]
 539                                 if remainder:
 540                                         splat_weights.append([v*r for v, r in zip(layer_values, remainder)])
 541                                         remainder = [(1-v)*r for v, r in zip(layer_values, remainder)]
 542                                 else:
 543                                         splat_weights.append(layer_values)
 544                                         remainder = [1-v for v in layer_values]
 545
 546                 splat_weights = list(zip(*splat_weights))
 547
 548                 for f in self.faces:
 549                         for i in f.loop_indices:
 550                                 f.splat_mask |= sum(1<<j for j, w in enumerate(splat_weights[i]) if w>0)
 551
 552                 self.split_vertices(self.find_splat_group, task)
 553
 554                 for v in self.vertices:
 555                         if v.faces:
 556                                 f = v.faces[0]
 557                                 weights = splat_weights[f.get_loop_index(v)]
 558                                 v.groups = [VertexGroup(i, w) for i, w in enumerate(weights) if (f.splat_mask>>i)&1]
 559                         else:
 560                                 v.groups = []
 561                         while len(v.groups)<self.max_groups_per_vertex:
 562                                 v.groups.append(VertexGroup(None))
 563
 564         def split_vertices(self, find_group_func, task, *args):
 565                 vertex_count = len(self.vertices)
 566                 for i in range(vertex_count):
 567                         v = self.vertices[i]
 568                         for f in v.faces:
 569                                 f.flag = False
 570
 571                         # Find all groups of faces on this vertex
 572                         groups = []
 573                         for f in v.faces:
 574                                 if not f.flag:
 575                                         groups.append(find_group_func(v, f, *args))
 576
 577                         # Give groups after the first separate copies of the vertex
 578                         for g in groups[1:]:
 579                                 nv = Vertex(v)
 580                                 nv.index = len(self.vertices)
 581                                 self.vertices.append(nv)
 582
 583                                 for e in v.edges:
 584                                         e_faces_in_g = [f for f in e.faces if f in g]
 585                                         if not e_faces_in_g:
 586                                                 continue
 587
 588                                         if len(e_faces_in_g)<len(e.faces):
 589                                                 # Create a copy of an edge at the boundary of the group
 590                                                 ne = Edge(e)
 591                                                 ne.index = len(self.edges)
 592                                                 self.edges.append(ne)
 593
 594                                                 ne.other_vertex(v).edges.append(ne)
 595
 596                                                 for f in e_faces_in_g:
 597                                                         e.faces.remove(f)
 598                                                         f.edges[f.edges.index(e)] = ne
 599                                                         ne.faces.append(f)
 600
 601                                                 e = ne
 602
 603                                         e.vertices[e.vertices.index(v)] = nv
 604                                         nv.edges.append(e)
 605
 606                                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 607
 608                                 # Filter out any edges that were removed from the original vertex
 609                                 v.edges = [e for e in v.edges if v in e.vertices]
 610
 611                                 for f in g:
 612                                         v.faces.remove(f)
 613                                         f.vertices[f.vertices.index(v)] = nv
 614                                         nv.faces.append(f)
 615
 616                         task.set_progress(i/vertex_count)
 617
 618         def find_smooth_group(self, vertex, face):
 619                 face.flag = True
 620
 621                 edges = [e for e in face.edges if vertex in e.vertices]
 622
 623                 group = [face]
 624                 for e in edges:
 625                         f = face
 626                         while e.smooth:
 627                                 f = e.other_face(f)
 628                                 if not f or f.flag:
 629                                         break
 630
 631                                 f.flag = True
 632                                 group.append(f)
 633                                 e = f.other_edge(e, vertex)
 634
 635                 return group
 636
 637         def find_uv_group(self, vertex, face, index):
 638                 layer = self.uv_layers[index]
 639                 uv = layer.uvs[face.get_loop_index(vertex)]
 640                 face.flag = True
 641
 642                 group = [face]
 643                 for f in vertex.faces:
 644                         if not f.flag and layer.uvs[f.get_loop_index(vertex)]==uv:
 645                                 f.flag = True
 646                                 group.append(f)
 647
 648                 return group
 649
 650         def find_color_group(self, vertex, face):
 651                 color = self.colors.colors[face.get_loop_index(vertex)]
 652                 face.flag = True
 653
 654                 group = [face]
 655                 for f in vertex.faces:
 656                         if not f.flag and self.colors.colors[f.get_loop_index(vertex)]==color:
 657                                 f.flag = True
 658                                 group.append(f)
 659
 660                 return group
 661
 662         def find_splat_group(self, vertex, face):
 663                 face.flag = True
 664
 665                 group = [face]
 666                 for f in vertex.faces:
 667                         if not f.flag and f.splat_mask==face.splat_mask:
 668                                 f.flag = True
 669                                 group.append(f)
 670
 671                 return group
 672
 673         def compute_normals(self, task):
 674                 for i, v in enumerate(self.vertices):
 675                         v.normal = mathutils.Vector()
 676                         for f in v.faces:
 677                                 vi = f.pivot_vertex(v)
 678                                 edge1 = f.vertices[vi[1]].co-v.co
 679                                 edge2 = f.vertices[vi[-1]].co-v.co
 680                                 if edge1.length and edge2.length:
 681                                         # Use the angle between edges as a weighting factor.  This gives
 682                                         # more consistent normals on bends with an inequal number of
 683                                         # faces on each side.
 684                                         v.normal += f.normal*edge1.angle(edge2)
 685
 686                         if v.normal.length:
 687                                 v.normal.normalize()
 688                         else:
 689                                 v.normal = mathutils.Vector((0, 0, 1))
 690
 691                         task.set_progress(i/len(self.vertices))
 692
 693         def compute_tangents(self, index, task):
 694                 layer_uvs = self.uv_layers[index].uvs
 695
 696                 for i, v in enumerate(self.vertices):
 697                         v.tan = mathutils.Vector()
 698                         for f in v.faces:
 699                                 vi = f.pivot_vertex(v)
 700                                 uv0 = layer_uvs[f.loop_indices[vi[0]]]
 701                                 uv1 = layer_uvs[f.loop_indices[vi[1]]]
 702                                 uv2 = layer_uvs[f.loop_indices[vi[-1]]]
 703                                 du1 = uv1[0]-uv0[0]
 704                                 du2 = uv2[0]-uv0[0]
 705                                 dv1 = uv1[1]-uv0[1]
 706                                 dv2 = uv2[1]-uv0[1]
 707                                 edge1 = f.vertices[vi[1]].co-f.vertices[vi[0]].co
 708                                 edge2 = f.vertices[vi[-1]].co-f.vertices[vi[0]].co
 709                                 div = (du1*dv2-du2*dv1)
 710                                 if div:
 711                                         mul = edge1.angle(edge2)/div
 712                                         v.tan += (edge1*dv2-edge2*dv1)*mul
 713
 714                         if v.tan.length:
 715                                 v.tan.normalize()
 716
 717                         task.set_progress(i/len(self.vertices))
 718
 719         def prepare_sequence(self, task):
 720                 if self.use_patches:
 721                         subtask = task.task("Reordering patches", 0.5)
 722                         self.reorder_patches(subtask)
 723
 724                         subtask = task.task("Building sequence", 1.0)
 725                         self.build_patch_sequence(subtask)
 726                 else:
 727                         subtask = task.task("Reordering faces", 0.5)
 728                         self.reorder_faces(subtask)
 729
 730                         subtask = task.task("Building sequence", 1.0)
 731                         if self.use_strips:
 732                                 self.build_tristrip_sequence(subtask)
 733                         else:
 734                                 self.build_triangle_sequence(subtask)
 735
 736                         if self.use_lines:
 737                                 self.build_line_sequence()
 738
 739                 self.reorder_vertices()
 740
 741         def build_tristrip_sequence(self, task):
 742                 sequence = None
 743                 for i, f in enumerate(self.faces):
 744                         if sequence:
 745                                 if len(sequence)==3:
 746                                         # Rotate the first three vertices so that the new face can be added
 747                                         if sequence[0] in f.vertices and sequence[1] not in f.vertices:
 748                                                 sequence.append(sequence[0])
 749                                                 del sequence[0]
 750                                         elif sequence[2] not in f.vertices and sequence[1] in f.vertices:
 751                                                 sequence.insert(0, sequence[-1])
 752                                                 del sequence[-1]
 753
 754                                 if sequence[-1] not in f.vertices:
 755                                         sequence = None
 756                                 else:
 757                                         to_add = [v for v in f.vertices if v!=sequence[-1] and v!=sequence[-2]]
 758                                         if len(to_add)==2:
 759                                                 if (f.vertices[1]==sequence[-1]) != (len(sequence)%2==1):
 760                                                         to_add.reverse()
 761                                                 sequence.append(sequence[-1])
 762                                         sequence += to_add
 763
 764                         if not sequence:
 765                                 self.batches.append(Batch("TRIANGLE_STRIP"))
 766                                 sequence = self.batches[-1].vertices
 767                                 sequence += f.vertices
 768
 769                         task.set_progress(i/len(self.faces))
 770
 771         def build_triangle_sequence(self, task):
 772                 batch = Batch("TRIANGLES")
 773                 for f in self.faces:
 774                         batch.vertices += f.vertices
 775                 self.batches.append(batch)
 776
 777         def build_line_sequence(self):
 778                 batch = Batch("LINES")
 779                 for l in self.lines:
 780                         batch.vertices += l.vertices
 781                 self.batches.append(batch)
 782
 783         def build_patch_sequence(self, task):
 784                 current_size = 0
 785                 sequence = None
 786                 for f in self.faces:
 787                         if len(f.vertices)!=current_size:
 788                                 current_size = len(f.vertices)
 789                                 self.batches.append(Batch("PATCHES"))
 790                                 self.batches[-1].patch_size = current_size
 791                                 sequence = self.batches[-1].vertices
 792
 793                         sequence += f.vertices
 794
 795         def reorder_faces(self, task):
 796                 # Tom Forsyth's vertex cache optimization algorithm
 797                 # http://eelpi.gotdns.org/papers/fast_vert_cache_opt.html
 798
 799                 for f in self.faces:
 800                         f.flag = False
 801
 802                 last_triangle_score = 0.75
 803                 cache_decay_power = 1.5
 804                 valence_boost_scale = 2.0
 805                 valence_boost_power = -0.5
 806
 807                 max_cache_size = 32
 808                 cached_vertices = []
 809
 810                 # Keep track of the score and number of unused faces for each vertex
 811                 vertex_info = [[0, len(v.faces)] for v in self.vertices]
 812                 for vi in vertex_info:
 813                         if vi[1]:
 814                                 vi[0] = valence_boost_scale*(vi[1]**valence_boost_power)
 815
 816                 face = None
 817                 reordered_faces = []
 818
 819                 n_processed = 0
 820                 while 1:
 821                         if not face:
 822                                 # Previous iteration gave no candidate for best face (or this is
 823                                 # the first iteration).  Scan all faces for the highest score.
 824                                 best_score = 0
 825                                 for f in self.faces:
 826                                         if f.flag:
 827                                                 continue
 828
 829                                         score = sum(vertex_info[v.index][0] for v in f.vertices)
 830                                         if score>best_score:
 831                                                 best_score = score
 832                                                 face = f
 833
 834                         if not face:
 835                                 break
 836
 837                         reordered_faces.append(face)
 838                         face.flag = True
 839
 840                         for v in face.vertices:
 841                                 vertex_info[v.index][1] -= 1
 842
 843                                 # Shuffle the vertex into the front of the cache
 844                                 if v in cached_vertices:
 845                                         cached_vertices.remove(v)
 846                                 cached_vertices.insert(0, v)
 847
 848                         # Update scores for all vertices in the cache
 849                         for i, v in enumerate(cached_vertices):
 850                                 score = 0
 851                                 if i<3:
 852                                         score += last_triangle_score
 853                                 elif i<max_cache_size:
 854                                         score += (1-(i-3)/(max_cache_size-3))**cache_decay_power
 855                                 if vertex_info[v.index][1]:
 856                                         score += valence_boost_scale*(vertex_info[v.index][1]**valence_boost_power)
 857                                 vertex_info[v.index][0] = score
 858
 859                         face = None
 860                         best_score = 0
 861                         for v in cached_vertices:
 862                                 for f in v.faces:
 863                                         if not f.flag:
 864                                                 score = sum(vertex_info[fv.index][0] for fv in f.vertices)
 865                                                 if score>best_score:
 866                                                         best_score = score
 867                                                         face = f
 868
 869                         del cached_vertices[max_cache_size:]
 870
 871                         n_processed += 1
 872                         task.set_progress(n_processed/len(self.faces))
 873
 874                 self.faces = reordered_faces
 875                 for i, f in enumerate(self.faces):
 876                         f.index = i
 877
 878         def reorder_patches(self, task):
 879                 for f in self.faces:
 880                         f.flag = False
 881
 882                 reordered_faces = []
 883                 n_processed = 0
 884
 885                 while 1:
 886                         current_size = 0
 887
 888                         for f in self.faces:
 889                                 if f.flag:
 890                                         continue
 891
 892                                 if not current_size:
 893                                         current_size = len(f.vertices)
 894                                 elif len(f.vertices)!=current_size:
 895                                         continue
 896
 897                                 reordered_faces.append(f)
 898                                 f.flag = True
 899
 900                                 n_processed += 1
 901                                 task.set_progress(n_processed/len(self.faces))
 902
 903                         if not current_size:
 904                                 break
 905
 906         def reorder_vertices(self):
 907                 for v in self.vertices:
 908                         v.index = -1
 909
 910                 reordered_vertices = []
 911                 for b in self.batches:
 912                         for v in b.vertices:
 913                                 if v.index<0:
 914                                         v.index = len(reordered_vertices)
 915                                         reordered_vertices.append(v)
 916
 917                 for v in self.vertices:
 918                         if v.index<0:
 919                                 v.index = len(reordered_vertices)
 920                                 reordered_vertices.append(v)
 921
 922                 self.vertices = reordered_vertices
 923
 924                 for e in self.edges:
 925                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 926
 927
 928 def create_mesh_from_object(ctx, obj):
 929         if obj.type!="MESH":
 930                 raise Exception("Object {} is not a mesh".format(obj.name))
 931
 932         task = ctx.task("Collecting mesh data", 0.2)
 933
 934         objs = [(obj, mathutils.Matrix())]
 935         i = 0
 936         while i<len(objs):
 937                 o, m = objs[i]
 938                 i += 1
 939                 for c in o.children:
 940                         if c.type=="MESH" and c.compound:
 941                                 objs.append((c, m*c.matrix_local))
 942
 943         dg = ctx.context.evaluated_depsgraph_get()
 944
 945         mesh = None
 946         for o, m in objs:
 947                 eval_obj = o.evaluated_get(dg)
 948                 bmesh = eval_obj.to_mesh()
 949
 950                 # Object.to_mesh does not copy custom properties
 951                 bmesh.smoothing = o.data.smoothing
 952                 bmesh.use_lines = o.data.use_lines
 953                 bmesh.vertex_groups = o.data.vertex_groups
 954                 bmesh.max_groups_per_vertex = o.data.max_groups_per_vertex
 955                 bmesh.use_uv = o.data.use_uv
 956                 bmesh.tangent_vecs = o.data.tangent_vecs
 957                 bmesh.tangent_uvtex = o.data.tangent_uvtex
 958
 959                 me = Mesh(bmesh)
 960                 me.transform(m)
 961
 962                 for i, s in enumerate(eval_obj.material_slots):
 963                         if s.link=='OBJECT':
 964                                 me.materials[i] = s.material
 965
 966                 if mesh:
 967                         mesh.splice(me)
 968                 else:
 969                         mesh = me
 970
 971         mesh.name = obj.data.name
 972
 973         task = ctx.task("Triangulating", 0.3)
 974         mesh.prepare_triangles(task)
 975         task = ctx.task("Smoothing", 0.5)
 976         mesh.prepare_smoothing(task)
 977         if mesh.splat_sources:
 978                 task = ctx.task("Splat weights", 0.6)
 979                 mesh.prepare_splat_weights(task)
 980         else:
 981                 task = ctx.task("Vertex groups", 0.6)
 982                 mesh.prepare_vertex_groups(obj)
 983         task = ctx.task("Preparing UVs", 0.75)
 984         mesh.prepare_uv(task)
 985         task = ctx.task("Preparing vertex colors", 0.85)
 986         mesh.prepare_colors(task)
 987         task = ctx.task("Render sequence", 1.0)
 988         mesh.prepare_sequence(task)
 989
 990         return mesh