blender/io_mspgl/mesh.py

   1 import math
   2 import mathutils
   3
   4 def make_edge_key(i1, i2):
   5         return (min(i1, i2), max(i1, i2))
   6
   7 class Edge:
   8         def __init__(self, me):
   9                 if me.__class__==Edge:
  10                         self._medge = me._medge
  11                         self.vertices = me.vertices[:]
  12                         self.smooth = me.smooth
  13                 else:
  14                         self._medge = me
  15                         self.smooth = False
  16                 self.faces = []
  17
  18         def __getattr__(self, attr):
  19                 return getattr(self._medge, attr)
  20
  21         def check_smooth(self, limit):
  22                 if len(self.faces)!=2:
  23                         return
  24
  25                 d = self.faces[0].normal.dot(self.faces[1].normal)
  26                 self.smooth = ((d>limit and self.faces[0].use_smooth and self.faces[1].use_smooth) or d>0.99995)
  27
  28         def other_face(self, f):
  29                 if f.index==self.faces[0].index:
  30                         if len(self.faces)>=2:
  31                                 return self.faces[1]
  32                         else:
  33                                 return None
  34                 else:
  35                         return self.faces[0]
  36
  37         def other_vertex(self, v):
  38                 if v.index==self.vertices[0].index:
  39                         return self.vertices[1]
  40                 else:
  41                         return self.vertices[0]
  42
  43
  44 class Vertex:
  45         def __init__(self, mv):
  46                 if mv.__class__==Vertex:
  47                         self._mvert = mv._mvert
  48                         self.normal = mv.normal
  49                         self.uvs = mv.uvs[:]
  50                         self.tan = mv.tan
  51                         self.bino = mv.bino
  52                         self.group_weight_scale = mv.group_weight_scale
  53                 else:
  54                         self._mvert = mv
  55                         self.uvs = []
  56                         self.tan = None
  57                         self.bino = None
  58                         self.group_weight_scale = 1
  59                 self.flag = False
  60                 self.faces = []
  61
  62         def __getattr__(self, attr):
  63                 return getattr(self._mvert, attr)
  64
  65         def __cmp__(self, other):
  66                 if other is None:
  67                         return 1
  68                 return cmp(self.index, other.index)
  69
  70
  71 class Face:
  72         def __init__(self, mf):
  73                 self._mface = mf
  74                 self.edges = []
  75                 self.vertices = mf.vertices[:]
  76                 self.uvs = []
  77                 self.flag = False
  78
  79         def __getattr__(self, attr):
  80                 return getattr(self._mface, attr)
  81
  82         def __cmp__(self, other):
  83                 if other is None:
  84                         return 1
  85                 return cmp(self.index, other.index)
  86
  87         def pivot_vertices(self, *vt):
  88                 flags = [(v in vt) for v in self.vertices]
  89                 l = len(self.vertices)
  90                 for i in range(l):
  91                         if flags[i] and not flags[(i+l-1)%l]:
  92                                 return self.vertices[i:]+self.vertices[:i]
  93
  94         def get_edge(self, v1, v2):
  95                 key = make_edge_key(v1.index, v2.index)
  96                 for e in self.edges:
  97                         if e.key==key:
  98                                 return e
  99                 raise KeyError("No edge %s"%(key,))
 100
 101         def get_neighbors(self):
 102                 neighbors = [e.other_face(self) for e in self.edges]
 103                 return list(filter(bool, neighbors))
 104
 105
 106 class Line:
 107         def __init__(self, e):
 108                 self.edge = e
 109                 self.vertices = e.vertices[:]
 110                 self.flag = False
 111
 112
 113 class UvLayer:
 114         def __init__(self, l, t):
 115                 self._layer = l
 116                 self.uvtex = t
 117                 self.name = self.uvtex.name
 118                 self.unit = None
 119                 self.hidden = False
 120                 dot = self.name.find('.')
 121                 if dot>=0:
 122                         ext = self.name[dot:]
 123                         if ext.startswith(".unit") and ext[5:].isdigit():
 124                                 self.unit = int(ext[5:])
 125                         elif ext==".hidden":
 126                                 self.hidden = True
 127
 128         def __getattr__(self, attr):
 129                 return getattr(self._layer, attr)
 130
 131 class FakeUvLayer:
 132         def __init__(self, n):
 133                 self.uvtex = None
 134                 self.name = n
 135                 self.unit = None
 136                 self.hidden = False
 137
 138 class Mesh:
 139         def __init__(self, m):
 140                 self._mesh = m
 141
 142                 self.vertices = [Vertex(v) for v in self.vertices]
 143                 self.faces = [Face(f) for f in self.polygons]
 144
 145                 self.materials = self.materials[:]
 146
 147                 self.uv_layers = [UvLayer(self.uv_layers[i], self.uv_textures[i]) for i in range(len(self.uv_layers))]
 148                 self.assign_texture_units()
 149
 150                 for f in self.faces:
 151                         if len(f.vertices)>4:
 152                                 raise ValueError("Ngons are not supported")
 153                         f.vertices = [self.vertices[i] for i in f.vertices]
 154                         for v in f.vertices:
 155                                 v.faces.append(f)
 156                         for u in self.uv_layers:
 157                                 f.uvs.append([u.data[f.loop_indices[i]].uv for i in range(len(f.vertices))])
 158
 159                 self.edges = dict([(e.key, Edge(e)) for e in self.edges])
 160                 for f in self.faces:
 161                         for k in f.edge_keys:
 162                                 e = self.edges[k]
 163                                 e.faces.append(self.faces[f.index])
 164                                 f.edges.append(e)
 165
 166                 self.lines = [Line(e) for e in self.edges.values() if not e.faces]
 167                 for l in self.lines:
 168                         l.vertices = [self.vertices[i] for i in l.vertices]
 169
 170                 if self.use_auto_smooth:
 171                         smooth_limit = math.cos(self.auto_smooth_angle)
 172                 else:
 173                         smooth_limit = -1
 174
 175                 for e in self.edges.values():
 176                         e.vertices = [self.vertices[i] for i in e.vertices]
 177                         e.check_smooth(smooth_limit)
 178
 179         def __getattr__(self, attr):
 180                 return getattr(self._mesh, attr)
 181
 182         def splice(self, other):
 183                 material_map = []
 184                 for m in other.materials:
 185                         if m in self.materials:
 186                                 material_map.append(self.materials.index(m))
 187                         else:
 188                                 material_map.append(len(self.materials))
 189                                 self.materials.append(m)
 190
 191                 offset = len(self.vertices)
 192                 for v in other.vertices:
 193                         v.index += offset
 194                         self.vertices.append(v)
 195
 196                 offset = len(self.faces)
 197                 for f in other.faces:
 198                         f.index += offset
 199                         if other.materials:
 200                                 f.material_index = material_map[f.material_index]
 201                         self.faces.append(f)
 202
 203                 for e in other.edges.values():
 204                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 205                         self.edges[e.key] = e
 206
 207                 self.lines += other.lines
 208
 209         def flatten_faces(self):
 210                 for f in self.faces:
 211                         f.use_smooth = False
 212
 213                 for e in self.edges.values():
 214                         e.check_smooth(1)
 215
 216         def assign_texture_units(self):
 217                 # Assign texture units for any non-hidden UV layers that lack one
 218                 units = [u.unit for u in self.uv_layers if u.unit is not None]
 219                 if units:
 220                         free_unit = max(units)+1
 221                 else:
 222                         free_unit = 0
 223                 for u in self.uv_layers:
 224                         if u.unit is None:
 225                                 if not u.hidden:
 226                                         u.unit = free_unit
 227                                         free_unit += 1
 228
 229         def generate_material_uv(self):
 230                 self.uv_layers.append(FakeUvLayer("material_tex"))
 231                 self.assign_texture_units()
 232                 for f in self.faces:
 233                         f.uvs.append([((f.material_index+0.5)/len(self.materials), 0.5)]*len(f.vertices))
 234
 235         def split_vertices(self, find_group_func, progress, *args):
 236                 groups = []
 237                 for i in range(len(self.vertices)):
 238                         v = self.vertices[i]
 239                         for f in v.faces:
 240                                 f.flag = False
 241
 242                         vg = []
 243                         for f in v.faces:
 244                                 if not f.flag:
 245                                         vg.append(find_group_func(v, f, *args))
 246
 247                         groups.append(vg)
 248
 249                         if progress:
 250                                 progress.set_progress(i*0.5/len(self.vertices))
 251
 252                 for i in range(len(self.vertices)):
 253                         if len(groups[i])==1:
 254                                 continue
 255
 256                         for g in groups[i][1:]:
 257                                 v = Vertex(self.vertices[i])
 258                                 v.index = len(self.vertices)
 259                                 self.vertices.append(v)
 260
 261                                 v_edges = []
 262                                 v_edge_keys = set()
 263                                 for f in g:
 264                                         for e in f.edges:
 265                                                 if e.key in v_edge_keys or self.vertices[i] not in e.vertices:
 266                                                         continue
 267
 268                                                 e_faces_in_g = [c for c in e.faces if c in g]
 269                                                 boundary = len(e_faces_in_g)<len(e.faces)
 270                                                 v_edges.append((e, boundary, e_faces_in_g))
 271                                                 v_edge_keys.add(e.key)
 272
 273                                 for e, boundary, e_faces_in_g in v_edges:
 274                                         if boundary:
 275                                                 ne = Edge(e)
 276                                                 for c in e_faces_in_g:
 277                                                         e.faces.remove(c)
 278                                                         c.edges[c.edges.index(e)] = ne
 279                                                         ne.faces.append(c)
 280                                                 e = ne
 281                                         else:
 282                                                 del self.edges[e.key]
 283
 284                                         e.vertices[e.vertices.index(self.vertices[i])] = v
 285
 286                                         e.key = make_edge_key(e.vertices[0].index, e.vertices[1].index)
 287                                         self.edges[e.key] = e
 288
 289                                 for f in g:
 290                                         self.vertices[i].faces.remove(f)
 291                                         f.vertices[f.vertices.index(self.vertices[i])] = v
 292                                         v.faces.append(f)
 293
 294                         if progress:
 295                                 progress.set_progress(0.5+i*0.5/len(self.vertices))
 296
 297         def split_smooth(self, progress=None):
 298                 self.split_vertices(self.find_smooth_group, progress)
 299
 300         def split_uv(self, index, progress=None):
 301                 self.split_vertices(self.find_uv_group, progress, index)
 302
 303         def find_smooth_group(self, vertex, face):
 304                 face.flag = True
 305                 queue = [face]
 306
 307                 for f in queue:
 308                         for e in f.edges:
 309                                 other = e.other_face(f)
 310                                 if other not in vertex.faces:
 311                                         continue
 312
 313                                 if e.smooth:
 314                                         if not other.flag:
 315                                                 other.flag = True
 316                                                 queue.append(other)
 317
 318                 return queue
 319
 320         def find_uv_group(self, vertex, face, index):
 321                 uv = face.uvs[index][face.vertices.index(vertex)]
 322                 face.flag = True
 323                 group = [face]
 324                 for f in vertex.faces:
 325                         if not f.flag and f.uvs[index][f.vertices.index(vertex)]==uv:
 326                                 f.flag = True
 327                                 group.append(f)
 328                 return group
 329
 330         def compute_normals(self):
 331                 for v in self.vertices:
 332                         if v.faces:
 333                                 v.normal = mathutils.Vector()
 334                                 for f in v.faces:
 335                                         fv = f.pivot_vertices(v)
 336                                         edge1 = fv[1].co-fv[0].co
 337                                         edge2 = fv[-1].co-fv[0].co
 338                                         if edge1.length and edge2.length:
 339                                                 weight = 1
 340                                                 if len(f.get_edge(fv[0], fv[1]).faces)==1:
 341                                                         weight += 1
 342                                                 if len(f.get_edge(fv[0], fv[-1]).faces)==1:
 343                                                         weight += 1
 344                                                 v.normal += f.normal*edge1.angle(edge2)*weight
 345                                 if v.normal.length:
 346                                         v.normal.normalize()
 347                                 else:
 348                                         v.normal = mathutils.Vector((0, 0, 1))
 349                         else:
 350                                 # XXX Should use edges to compute normal
 351                                 v.normal = mathutils.Vector((0, 0, 1))
 352
 353         def compute_uv(self):
 354                 for v in self.vertices:
 355                         if v.faces:
 356                                 f = v.faces[0]
 357                                 i = f.vertices.index(v)
 358                                 v.uvs = [u[i] for u in f.uvs]
 359                         else:
 360                                 v.uvs = [(0.0, 0.0)]*len(self.uv_layers)
 361
 362         def compute_tbn(self, index):
 363                 if not self.uv_layers:
 364                         return
 365
 366                 for v in self.vertices:
 367                         v.tan = mathutils.Vector()
 368                         v.bino = mathutils.Vector()
 369                         for f in v.faces:
 370                                 fv = f.pivot_vertices(v)
 371                                 uv0 = fv[0].uvs[index]
 372                                 uv1 = fv[1].uvs[index]
 373                                 uv2 = fv[-1].uvs[index]
 374                                 du1 = uv1[0]-uv0[0]
 375                                 du2 = uv2[0]-uv0[0]
 376                                 dv1 = uv1[1]-uv0[1]
 377                                 dv2 = uv2[1]-uv0[1]
 378                                 edge1 = fv[1].co-fv[0].co
 379                                 edge2 = fv[-1].co-fv[0].co
 380                                 div = (du1*dv2-du2*dv1)
 381                                 if div:
 382                                         mul = edge1.angle(edge2)/div
 383                                         v.tan += (edge1*dv2-edge2*dv1)*mul
 384                                         v.bino += (edge2*du1-edge1*du2)*mul
 385
 386                         if v.tan.length:
 387                                 v.tan.normalize()
 388                         if v.bino.length:
 389                                 v.bino.normalize()
 390
 391         def sort_vertex_groups(self, max_groups):
 392                 for v in self.vertices:
 393                         if v.groups:
 394                                 v.groups = sorted(v.groups, key=(lambda g: g.weight), reverse=True)
 395                                 v.group_weight_scale = 1.0/sum(g.weight for g in v.groups[:max_groups])
 396
 397         def create_strip(self, face, max_len):
 398                 # Find an edge with another unused face next to it
 399                 edge = None
 400                 for e in face.edges:
 401                         other = e.other_face(face)
 402                         if other and not other.flag:
 403                                 edge = e
 404                                 break
 405
 406                 if not edge:
 407                         return None
 408
 409                 # Add initial vertices so that we'll complete the edge on the first
 410                 # iteration
 411                 vertices = face.pivot_vertices(*edge.vertices)
 412                 if len(vertices)==3:
 413                         result = [vertices[-1], vertices[0]]
 414                 else:
 415                         result = [vertices[-2], vertices[-1]]
 416
 417                 while 1:
 418                         face.flag = True
 419
 420                         vertices = face.pivot_vertices(*result[-2:])
 421                         k = len(result)%2
 422
 423                         # Quads need special handling because the winding of every other
 424                         # triangle in the strip is reversed
 425                         if len(vertices)==4 and not k:
 426                                 result.append(vertices[3])
 427                         result.append(vertices[2])
 428                         if len(vertices)==4 and k:
 429                                 result.append(vertices[3])
 430
 431                         if len(result)>=max_len:
 432                                 break
 433
 434                         # Hop over the last edge
 435                         edge = face.get_edge(*result[-2:])
 436                         face = edge.other_face(face)
 437                         if not face or face.flag:
 438                                 break
 439
 440                 return result