mesh_export.py

   1 #!BPY
   2 # $Id$
   3
   4 """
   5 Name: 'MSP GL Mesh (.mesh)...'
   6 Blender: 244
   7 Group: 'Export'
   8 """
   9
  10 import sys
  11 import math
  12 import bpy
  13 import Blender
  14
  15 def make_edge_key(i1, i2):
  16         return (min(i1, i2), max(i1, i2))
  17
  18
  19 class Edge:
  20         def __init__(self, me):
  21                 if me.__class__==Edge:
  22                         self._medge=me._medge
  23                         self.smooth=me.smooth
  24                 else:
  25                         self._medge=me
  26                         self.smooth=False
  27                 self.faces=[]
  28
  29         def __getattr__(self, attr):
  30                 return getattr(self._medge, attr)
  31
  32         def __cmp__(self, other):
  33                 return self is other
  34
  35         def check_smooth(self, limit):
  36                 if len(self.faces)!=2:
  37                         return
  38
  39                 d=Blender.Mathutils.DotVecs(self.faces[0].no, self.faces[1].no)
  40                 if (d>limit and self.faces[0].smooth and self.faces[1].smooth) or d>0.999:
  41                         self.smooth=True
  42
  43         def other_face(self, f):
  44                 if f.index==self.faces[0].index:
  45                         if len(self.faces)>=2:
  46                                 return self.faces[1]
  47                         else:
  48                                 return None
  49                 else:
  50                         return self.faces[0]
  51
  52
  53 class Vertex:
  54         def __init__(self, mv):
  55                 if mv.__class__==Vertex:
  56                         self._mvert=mv._mvert
  57                         self.uv=mv.uv
  58                 else:
  59                         self._mvert=mv
  60                         self.uv=None
  61                 self.orig_index=self._mvert.index
  62                 self.flag=False
  63                 self.faces=[]
  64
  65         def __getattr__(self, attr):
  66                 return getattr(self._mvert, attr)
  67
  68         def __cmp__(self, other):
  69                 if other is None:
  70                         return 1
  71                 return cmp(self.index, other.index)
  72
  73         def __str__(self):
  74                 return "<Vert %d (%.4f, %.4f, %.4f) (%.4f, %.4f, %.4f)>"%(self.index, self.co[0], self.co[1], self.co[2], self.no[0], self.no[1], self.no[2])
  75
  76         __repr__=__str__
  77
  78
  79 class Face:
  80         def __init__(self, mf):
  81                 self._mface=mf
  82                 self.edges=[]
  83                 self.verts=[v for v in mf.verts]
  84                 self.flag=False
  85
  86         def __getattr__(self, attr):
  87                 return getattr(self._mface, attr)
  88
  89         def __cmp__(self, other):
  90                 if other is None:
  91                         return 1
  92                 return cmp(self.index, other.index)
  93
  94         def __str__(self):
  95                 return "<Face %d (%s)>"%(self.index, " ".join([str(v.index) for v in self.verts]))
  96
  97         __repr__=__str__
  98
  99         def get_vertices_from(self, reverse, *vt):
 100                 verts=self.verts[:]
 101                 if reverse:
 102                         verts.reverse()
 103                 flags=[(v in vt) for v in verts]
 104                 l=len(verts)
 105                 for i in range(l):
 106                         if flags[i] and not flags[(i+l-1)%l]:
 107                                 return verts[i:]+verts[:i]
 108
 109         def get_edge(self, v1, v2):
 110                 key=make_edge_key(v1.index, v2.index)
 111                 for e in self.edges:
 112                         if e.key==key:
 113                                 return e
 114
 115
 116 class Line:
 117         def __init__(self, e):
 118                 self.edge=e
 119                 self.verts=[e.v1, e.v2]
 120                 self.flag=False
 121
 122         def __str__(self):
 123                 return "<Line (%d %d)>"%(self.verts[0].index, self.verts[1].index)
 124
 125         __repr__=__str__
 126
 127
 128 class Mesh:
 129         def __init__(self, m):
 130                 self._mesh=m
 131                 self.verts=[Vertex(v) for v in m.verts]
 132                 self.faces=[Face(f) for f in m.faces]
 133
 134                 for f in self.faces:
 135                         for i in range(len(f.verts)):
 136                                 f.verts[i]=self.verts[f.verts[i].index]
 137                                 f.verts[i].faces.append(f)
 138
 139                 self.edges=dict([(e.key, Edge(e)) for e in m.edges])
 140                 for f in self.faces:
 141                         for k in f.edge_keys:
 142                                 e=self.edges[k]
 143                                 e.faces.append(self.faces[f.index])
 144                                 f.edges.append(e)
 145
 146                 self.lines=[Line(e) for e in self.edges.itervalues() if not e.faces]
 147
 148                 smooth_limit=math.cos(m.degr*math.pi/180)
 149                 for e in self.edges.itervalues():
 150                         e.v1=self.verts[e.v1.index]
 151                         e.v2=self.verts[e.v2.index]
 152                         e.check_smooth(smooth_limit)
 153
 154         def __getattr__(self, attr):
 155                 return getattr(self._mesh, attr)
 156
 157         def split_vertices(self, find_group_func, debug):
 158                 groups=[]
 159                 for v in self.verts:
 160                         for f in v.faces:
 161                                 f.flag=False
 162
 163                         vg=[]
 164                         for f in v.faces:
 165                                 if not f.flag:
 166                                         vg.append(find_group_func(v, f))
 167
 168                         groups.append(vg)
 169
 170                 for i in range(len(self.verts)):
 171                         if len(groups[i])==1:
 172                                 continue
 173
 174                         if debug:
 175                                 print "Vertex %s has %d groups"%(self.verts[i], len(groups[i]))
 176
 177                         for g in groups[i][1:]:
 178                                 v=Vertex(self.verts[i])
 179                                 v.index=len(self.verts)
 180                                 self.verts.append(v)
 181
 182                                 if debug:
 183                                         print "  -> %d"%v.index
 184
 185                                 for f in g:
 186                                         for j in range(len(f.edges)):
 187                                                 e=f.edges[j]
 188
 189                                                 if e.v1!=self.verts[i] and e.v2!=self.verts[i]:
 190                                                         continue
 191
 192                                                 if debug:
 193                                                         print "  Splitting edge %s with faces %s"%(e.key, e.faces)
 194
 195                                                 if e.other_face(f) not in g and len(e.faces)>=2:
 196                                                         k=e.faces.index(f)
 197                                                         e.faces.remove(f)
 198                                                         e=Edge(e)
 199                                                         f.edges[j]=e
 200                                                         e.faces.append(f)
 201                                                 else:
 202                                                         del self.edges[e.key]
 203
 204                                                 if e.v1==self.verts[i]:
 205                                                         e.v1=v
 206                                                 elif e.v2==self.verts[i]:
 207                                                         e.v2=v
 208
 209                                                 e.key=make_edge_key(e.v1.index, e.v2.index)
 210                                                 self.edges[e.key]=e
 211
 212                                         self.verts[i].faces.remove(f)
 213                                         f.verts[f.verts.index(self.verts[i])]=v
 214                                         v.faces.append(f)
 215
 216         def split_smooth(self, debug=False):
 217                 self.split_vertices(self.find_smooth_group, debug)
 218
 219         def split_uv(self, debug=False):
 220                 self.split_vertices(self.find_uv_group, debug)
 221
 222         def find_smooth_group(self, vert, face):
 223                 face.flag=True
 224                 queue=[face]
 225
 226                 for f in queue:
 227                         for e in f.edges:
 228                                 other=e.other_face(f)
 229                                 #if not other or other.index not in face_indices:
 230                                 if other not in vert.faces:
 231                                         continue
 232
 233                                 if e.smooth:
 234                                         if not other.flag:
 235                                                 other.flag=True
 236                                                 queue.append(other)
 237
 238                 return queue
 239
 240         def find_uv_group(self, vert, face):
 241                 uv=face.uv[face.verts.index(vert)]
 242                 face.flag=True
 243                 group=[face]
 244                 for f in vert.faces:
 245                         if not f.flag and f.uv[f.verts.index(vert)]==uv:
 246                                 f.flag=True
 247                                 group.append(f)
 248                 return group
 249
 250         def compute_normals(self):
 251                 for v in self.verts:
 252                         if v.faces:
 253                                 v.no=Blender.Mathutils.Vector()
 254                                 for f in v.faces:
 255                                         v.no+=f.no
 256                                 v.no.normalize()
 257                         else:
 258                                 # XXX Should use edges to compute normal
 259                                 v.no=Blender.Mathutils.Vector(0, 0, 1)
 260
 261         def compute_uv(self):
 262                 for v in self.verts:
 263                         if v.faces:
 264                                 v.uv=v.faces[0].uv[v.faces[0].verts.index(v)]
 265
 266         def create_strip(self, face, reverse, debug):
 267                 edge=None
 268                 for e in face.edges:
 269                         other=e.other_face(face)
 270                         if other and not other.flag:
 271                                 edge=e
 272                                 break
 273
 274                 if not edge:
 275                         return None
 276
 277                 if debug:
 278                         print "Starting strip from %s, edge %s, reverse=%s"%([v.index for v in face.verts], (edge.v1.index, edge.v2.index), reverse)
 279
 280                 verts=face.get_vertices_from(reverse, edge.v1, edge.v2)
 281                 if len(verts)==3:
 282                         result=[verts[-1], verts[0]]
 283                 else:
 284                         result=[verts[-2], verts[-1]]
 285
 286                 while 1:
 287                         verts=face.get_vertices_from(reverse, *result[-2:])
 288                         k=len(result)%2
 289                         if debug:
 290                                 print "  Adding %s"%face
 291
 292                         face.flag=True
 293                         if len(verts)==4 and not k:
 294                                 result.append(verts[3])
 295                         result.append(verts[2])
 296                         if len(verts)==4 and k:
 297                                 result.append(verts[3])
 298
 299                         edge=face.get_edge(*result[-2:])
 300
 301                         if debug:
 302                                 print "  Next edge is %s"%(edge.key, )
 303
 304                         next=edge.other_face(face)
 305                         if not next or next.flag:
 306                                 break
 307                         face=next
 308
 309                 if debug:
 310                         print "  %s"%[v.index for v in result]
 311
 312                 return result
 313
 314
 315 class Exporter:
 316         def __init__(self, fn):
 317                 self.filename=fn
 318                 if fn==None:
 319                         self.out_file=sys.stdout
 320                 else:
 321                         self.out_file=file(fn, "w")
 322                 self.use_strips=True
 323                 self.use_degen_tris=True
 324                 self.optimize_locality=True
 325                 self.export_lines=True
 326                 self.debug=False
 327                 self.strip_debug=False
 328                 self.split_debug=False
 329
 330         def get_locality(self, strip):
 331                 total=0
 332                 for i in range(1, len(strip)):
 333                         if strip[i].index!=strip[i-1].index:
 334                                 total+=1.0/(abs(strip[i].index-strip[i-1].index))
 335                 return total/len(strip)
 336
 337         def get_followers(self, strip):
 338                 result={}
 339                 for i in range(len(strip)-1):
 340                         v=strip[i]
 341                         n=strip[i+1]
 342                         if v.index!=n.index:
 343                                 if v.index not in result:
 344                                         result[v.index]={}
 345                                 if n.index not in result[v.index]:
 346                                         result[v.index][n.index]=1
 347                                 else:
 348                                         result[v.index][n.index]+=1
 349                 return result
 350
 351         def export(self):
 352                 scene=bpy.data.scenes.active
 353
 354                 obj=scene.objects.active
 355                 if obj.getType()!="Mesh":
 356                         raise Exception, "Can only export Mesh data"
 357
 358                 mesh=Mesh(obj.getData(mesh=True))
 359
 360                 if self.debug:
 361                         ntris=sum([len(f.verts)-2 for f in mesh.faces])
 362                         print "Starting with %d vertices, %d faces (%d triangles) and %d edges"%(len(mesh.verts), len(mesh.faces), ntris, len(mesh.edges))
 363
 364                 mesh.split_smooth(self.split_debug)
 365
 366                 if self.debug:
 367                         print "After smooth splitting %d vertices and %d edges"%(len(mesh.verts), len(mesh.edges))
 368
 369                 mesh.compute_normals()
 370
 371                 if mesh.faceUV:
 372                         mesh.split_uv(self.split_debug)
 373                         if self.debug:
 374                                 print "After UV splitting %d vertices and %d edges"%(len(mesh.verts), len(mesh.edges))
 375
 376                         mesh.compute_uv()
 377
 378                 strips=[]
 379                 if self.use_strips:
 380                         for f in mesh.faces:
 381                                 f.flag=False
 382
 383                         while 1:
 384                                 best=5
 385                                 face=None
 386                                 for f in mesh.faces:
 387                                         if f.flag:
 388                                                 continue
 389                                         score=0
 390                                         for e in f.edges:
 391                                                 other=e.other_face(f)
 392                                                 if other and not other.flag:
 393                                                         score+=1
 394                                         if score>0 and score<best:
 395                                                 face=f
 396                                                 best=score
 397
 398                                 if not face:
 399                                         break
 400
 401                                 strip=mesh.create_strip(face, self.use_degen_tris and sum([len(s) for s in strips])%2, self.strip_debug)
 402                                 if strip:
 403                                         strips.append(strip)
 404
 405                         if self.debug:
 406                                 print "%d strips:"%len(strips)
 407                                 for i in range(len(strips)):
 408                                         print "  %d: %d indices"%(i, len(strips[i]))
 409                                 print "%d loose faces"%len([f for f in mesh.faces if not f.flag])
 410                                 nind=sum([len(s) for s in strips])+sum([len(f.verts) for f in mesh.faces if not f.flag])
 411                                 print "%d indices total"%nind
 412
 413                         if self.use_degen_tris and strips:
 414                                 big_strip=[]
 415                                 for s in strips:
 416                                         if big_strip:
 417                                                 big_strip+=[big_strip[-1], s[0]]
 418                                         big_strip+=s
 419
 420                                 for f in mesh.faces:
 421                                         if not f.flag:
 422                                                 if len(big_strip)%2:
 423                                                         order=(-1, -2, 0, 1)
 424                                                 else:
 425                                                         order=(0, 1, -1, -2)
 426                                                 if big_strip:
 427                                                         big_strip+=[big_strip[-1], f.verts[order[0]]]
 428                                                 big_strip+=[f.verts[i] for i in order[:len(f.verts)]]
 429                                                 f.flag=True
 430
 431                                 strips=[big_strip]
 432
 433                                 if self.debug:
 434                                         nind=len(big_strip)
 435                                         print "Big strip has %d indices"%len(big_strip)
 436
 437                 if self.debug:
 438                         print "%.2f indices per triangle"%(float(nind)/max(ntris, 1))
 439                         print "Locality before optimization: "+" ".join(["%.3f"%self.get_locality(s) for s in strips])
 440
 441                 if self.optimize_locality and self.use_strips and strips:
 442                         followers={}
 443                         for s in strips:
 444                                 followers.update(self.get_followers(s))
 445
 446                         verts2=[]
 447                         vert=strips[0][0]
 448                         while 1:
 449                                 vert.flag=True
 450                                 verts2.append(vert)
 451
 452                                 next=None
 453                                 if vert.index in followers:
 454                                         flw=followers[vert.index]
 455                                         best=0
 456                                         for n in flw:
 457                                                 if flw[n]>best and not mesh.verts[n].flag:
 458                                                         next=mesh.verts[n]
 459                                                         best=flw[n]+0.9/abs(vert.index-n)
 460
 461                                 if not next:
 462                                         for v in mesh.verts:
 463                                                 if not v.flag:
 464                                                         next=v
 465                                                         break
 466                                         if not next:
 467                                                 break
 468
 469                                 vert=next
 470
 471                         mesh.verts=verts2
 472
 473                         for i in range(len(mesh.verts)):
 474                                 mesh.verts[i].index=i
 475
 476                         if self.debug:
 477                                 print "Locality after optimization: "+" ".join(["%.3f"%self.get_locality(s) for s in strips])
 478
 479                 self.out_file.write("vertices NORMAL3")
 480                 if mesh.faceUV:
 481                         self.out_file.write("_TEXCOORD2")
 482                 self.out_file.write("_VERTEX3\n{\n")
 483                 norm=None
 484                 uv=None
 485                 for v in mesh.verts:
 486                         if v.no!=norm:
 487                                 self.out_file.write("\tnormal3 %f %f %f;\n"%tuple(v.no))
 488                                 norm=v.no
 489                         if v.uv!=uv:
 490                                 self.out_file.write("\ttexcoord2 %f %f;\n"%tuple(v.uv))
 491                                 uv=v.uv
 492                         self.out_file.write("\tvertex3 %f %f %f;\n"%tuple(v.co))
 493                 self.out_file.write("};\n")
 494                 for s in strips:
 495                         self.out_file.write("batch TRIANGLE_STRIP\n{\n\tindices")
 496                         n=0
 497                         for v in s:
 498                                 self.out_file.write(" %u"%v.index)
 499                                 n+=1;
 500                                 if n%32==0:
 501                                         self.out_file.write(";\n\tindices")
 502                         self.out_file.write(";\n};\n")
 503
 504                 first=True
 505                 for f in mesh.faces:
 506                         if not f.flag:
 507                                 if first:
 508                                         self.out_file.write("batch TRIANGLES\n{\n")
 509                                         first=False
 510                                 for i in range(2, len(f.verts)):
 511                                         self.out_file.write("\tindices %u %u %u;\n"%(f.verts[0].index, f.verts[i-1].index, f.verts[i].index))
 512                 if not first:
 513                         self.out_file.write("};\n")
 514
 515                 if self.export_lines and mesh.lines:
 516                         self.out_file.write("batch LINES\n{\n")
 517                         for l in mesh.lines:
 518                                 self.out_file.write("\tindices %u %u;\n"%(l.verts[0].index, l.verts[1].index))
 519                         self.out_file.write("};\n")
 520
 521
 522 class FrontEnd:
 523         def __init__(self):
 524                 self.config=Blender.Registry.GetKey('mspgl_export', True) or {}
 525                 self.temp_config=Blender.Registry.GetKey('mspgl_export_temp') or {}
 526
 527         def run(self):
 528                 self.use_strips=Blender.Draw.Create(self.config.get('use_strips', True))
 529                 self.use_degen_tris=Blender.Draw.Create(self.config.get('use_degen_tris', True))
 530                 self.optimize_locality=Blender.Draw.Create(self.config.get('optimize_locality', True))
 531                 self.export_lines=Blender.Draw.Create(self.config.get('export_lines', False))
 532                 self.debug=Blender.Draw.Create(self.config.get('debug', False))
 533                 self.strip_debug=Blender.Draw.Create(self.config.get('strip_debug', False))
 534                 self.split_debug=Blender.Draw.Create(self.config.get('split_debug', False))
 535                 ret=Blender.Draw.PupBlock("Export MSP GL mesh",
 536                         [("Use strips", self.use_strips, "Generage OpenGL triangle strips"),
 537                                 ("Use degen tris", self.use_degen_tris, "Use degenerate triangles to combine triangle strips"),
 538                                 ("Optimize locality", self.optimize_locality),
 539                                 ("Export lines", self.export_lines),
 540                                 ("Debugging options"),
 541                                 ("Debug", self.debug),
 542                                 ("Debug strips", self.strip_debug),
 543                                 ("Debug splitting", self.split_debug)])
 544                 if ret:
 545                         dirname=self.temp_config.get("dirname", Blender.sys.dirname(Blender.Get("filename")))
 546                         obj=bpy.data.scenes.active.objects.active
 547                         Blender.Window.FileSelector(self.export, "Export MSP GL mesh", "%s/%s.mesh"%(dirname, obj.name))
 548
 549         def draw(self):
 550                 pass
 551
 552         def export(self, fn):
 553                 self.config['use_strips']=self.use_strips.val
 554                 self.config['use_degen_tris']=self.use_degen_tris.val
 555                 self.config['optimize_locality']=self.optimize_locality.val
 556                 self.config['export_lines']=self.export_lines.val
 557                 self.config['debug']=self.debug.val
 558                 self.config['strip_debug']=self.strip_debug.val
 559                 self.config['split_debug']=self.split_debug.val
 560                 Blender.Registry.SetKey('mspgl_export', self.config, True)
 561
 562                 import os
 563                 self.temp_config["dirname"]=os.path.dirname(fn)
 564                 Blender.Registry.SetKey('mspgl_export_temp', self.temp_config)
 565
 566                 exp=Exporter(fn)
 567                 exp.use_strips=self.use_strips.val
 568                 exp.use_degen_tris=self.use_degen_tris.val
 569                 exp.optimize_locality=self.optimize_locality.val
 570                 exp.export_lines=self.export_lines.val
 571                 exp.debug=self.debug.val
 572                 exp.strip_debug=self.strip_debug.val
 573                 exp.split_debug=self.split_debug.val
 574                 exp.export()
 575
 576
 577 if __name__=="__main__":
 578         fe=FrontEnd()
 579         fe.run()