blender/io_mspgl/export_mesh.py

   1 import itertools
   2 import bpy
   3 import mathutils
   4
   5 class VertexCache:
   6         def __init__(self, size):
   7                 self.size = size
   8                 self.slots = [-1]*self.size
   9
  10         def fetch(self, v):
  11                 hit = v.index in self.slots
  12                 if hit:
  13                         self.slots.remove(v.index)
  14                 self.slots.append(v.index)
  15                 if not hit:
  16                         del self.slots[0]
  17                 return hit
  18
  19         def fetch_strip(self, strip):
  20                 hits = 0
  21                 for v in strip:
  22                         if self.fetch(v):
  23                                 hits += 1
  24                 return hits
  25
  26         def test_strip(self, strip):
  27                 hits = 0
  28                 for i in range(len(strip)):
  29                         if i>=self.size:
  30                                 break
  31                         if strip[i].index in self.slots[i:]:
  32                                 hits += 1
  33                 return hits
  34
  35
  36 class MeshExporter:
  37         def __init__(self):
  38                 self.show_progress = True
  39                 self.use_strips = True
  40                 self.use_degen_tris = False
  41                 self.max_strip_len = 1024
  42                 self.optimize_cache = True
  43                 self.cache_size = 64
  44                 self.export_lines = False
  45                 self.export_uv = "UNIT0"
  46                 self.tbn_vecs = False
  47                 self.tbn_uvtex = ""
  48                 self.compound = False
  49                 self.material_tex = False
  50                 self.smoothing = "MSPGL"
  51                 self.export_groups = False
  52                 self.max_groups = 2
  53
  54         def stripify(self, mesh, progress=None):
  55                 for f in mesh.faces:
  56                         f.flag = False
  57
  58                 faces_done = 0
  59                 strips = []
  60                 loose = []
  61
  62                 cache = None
  63                 if self.optimize_cache:
  64                         cache = VertexCache(self.cache_size)
  65
  66                 island = []
  67                 face_neighbors = []
  68                 island_strips = []
  69                 while 1:
  70                         if not island:
  71                                 # No current island; find any unused face to start from
  72                                 queue = []
  73                                 for f in mesh.faces:
  74                                         if not f.flag:
  75                                                 f.flag = True
  76                                                 queue.append(f)
  77                                                 break
  78
  79                                 if not queue:
  80                                         break
  81
  82                                 # Find all faces connected to the first one
  83                                 while queue:
  84                                         face = queue.pop(0)
  85                                         island.append(face)
  86
  87                                         for n in face.get_neighbors():
  88                                                 if not n.flag:
  89                                                         n.flag = True
  90                                                         queue.append(n)
  91
  92                                 face_neighbors = [f.get_neighbors() for f in island]
  93
  94                                 # Unflag the island for the next phase
  95                                 for f in island:
  96                                         f.flag = False
  97
  98                         # Find an unused face with as few unused neighbors as possible, but
  99                         # at least one.  This heuristic gives a preference to faces in corners
 100                         # or along borders of a non-closed island.
 101                         best = 5
 102                         face = None
 103                         for i, f in enumerate(island):
 104                                 if f.flag:
 105                                         continue
 106
 107                                 score = sum(not n.flag for n in face_neighbors[i])
 108                                 if score>0 and score<best:
 109                                         face = f
 110                                         best = score
 111
 112                         if face:
 113                                 # Create a strip starting from the face.  This will flag the faces.
 114                                 strip = mesh.create_strip(face, self.max_strip_len)
 115                                 if strip:
 116                                         island_strips.append(strip)
 117                                 else:
 118                                         face.flag = True
 119                         else:
 120                                 # Couldn't find a candidate face for starting a strip, so we're
 121                                 # done with this island
 122                                 while island_strips:
 123                                         best = 0
 124                                         if cache:
 125                                                 # Find the strip that benefits the most from the current
 126                                                 # contents of the vertex cache
 127                                                 best_hits = 0
 128                                                 for i in range(len(island_strips)):
 129                                                         hits = cache.test_strip(island_strips[i])
 130                                                         if hits>best_hits:
 131                                                                 best = i
 132                                                                 best_hits = hits
 133
 134                                         strip = island_strips.pop(best)
 135                                         strips.append(strip)
 136
 137                                         if cache:
 138                                                 cache.fetch_strip(strip)
 139
 140                                 faces_done += len(island)
 141                                 if progress:
 142                                         progress.set_progress(float(faces_done)/len(mesh.faces))
 143
 144                                 # Collect any faces that weren't used in strips
 145                                 loose += [f for f in island if not f.flag]
 146                                 for f in island:
 147                                         f.flag = True
 148
 149                                 island = []
 150                                 island_strips = []
 151
 152                 if cache:
 153                         cache = VertexCache(self.cache_size)
 154                         total_hits = 0
 155
 156                 if self.use_degen_tris and strips:
 157                         big_strip = []
 158
 159                         for s in strips:
 160                                 if big_strip:
 161                                         # Generate glue elements, ensuring that the next strip begins at
 162                                         # an even position
 163                                         glue = [big_strip[-1], s[0]]
 164                                         if len(big_strip)%2:
 165                                                 glue += [s[0]]
 166
 167                                         big_strip += glue
 168                                         if cache:
 169                                                 total_hits += cache.fetch_strip(glue)
 170
 171                                 big_strip += s
 172                                 if cache:
 173                                         total_hits += cache.fetch_strip(s)
 174
 175                         for f in loose:
 176                                 # Add loose faces to the end.  This wastes space, using five
 177                                 # elements per triangle and six elements per quad.
 178                                 if len(big_strip)%2:
 179                                         order = (-1, -2, 0, 1)
 180                                 else:
 181                                         order = (0, 1, -1, -2)
 182                                 vertices = [f.vertices[i] for i in order[:len(f.vertices)]]
 183
 184                                 if big_strip:
 185                                         glue = [big_strip[-1], vertices[0]]
 186                                         big_strip += glue
 187                                         if cache:
 188                                                 total_hits += cache.fetch_strip(glue)
 189
 190                                 big_strip += vertices
 191                                 if cache:
 192                                         total_hits += cache.fetch_strip(vertices)
 193
 194                         strips = [big_strip]
 195                         loose = []
 196
 197                 return strips, loose
 198
 199         def export(self, context, out_file, objs=None, progress=None):
 200                 if objs:
 201                         objs = [(o, mathutils.Matrix()) for o in objs]
 202
 203                 if self.compound:
 204                         if objs is None:
 205                                 objs = [(o, mathutils.Matrix()) for o in context.selected_objects]
 206                         check = objs
 207                         while check:
 208                                 children = []
 209                                 for o, m in check:
 210                                         for c in o.children:
 211                                                 if c.compound:
 212                                                         children.append((c, m*c.matrix_local))
 213                                 objs += children
 214                                 check = children
 215                 elif objs is None:
 216                         objs = [(context.active_object, mathutils.Matrix())]
 217
 218                 if not objs:
 219                         raise Exception("Nothing to export")
 220                 for o, m in objs:
 221                         if o.type!="MESH":
 222                                 raise Exception("Can only export Mesh data")
 223
 224                 from .mesh import Mesh
 225                 from .util import Progress
 226
 227                 if self.show_progress:
 228                         if not progress:
 229                                 progress = Progress(context)
 230                         progress.set_task("Preparing", 0.0, 0.0)
 231                 else:
 232                         progress = None
 233
 234                 mesh = None
 235                 bmeshes = []
 236                 winding_test = False
 237                 for o, m in objs:
 238                         if o.data.winding_test:
 239                                 winding_test = True
 240                         bmesh = o.to_mesh(context.scene, True, "PREVIEW")
 241                         bmeshes.append(bmesh)
 242                         me = Mesh(bmesh)
 243                         me.transform(m)
 244                         if not mesh:
 245                                 mesh = me
 246                         else:
 247                                 mesh.splice(me)
 248
 249                 if progress:
 250                         progress.set_task("Smoothing", 0.05, 0.35)
 251                 if self.smoothing=="NONE":
 252                         mesh.flatten_faces()
 253                 mesh.split_smooth(progress)
 254
 255                 if self.smoothing!="BLENDER":
 256                         mesh.compute_normals()
 257
 258                 if self.export_groups:
 259                         mesh.sort_vertex_groups(self.max_groups)
 260
 261                         # Create a mapping from vertex group indices to bone indices
 262                         first_obj = objs[0][0]
 263                         group_index_map = dict((i, i) for i in range(len(first_obj.vertex_groups)))
 264                         if first_obj.parent and first_obj.parent.type=="ARMATURE":
 265                                 armature = first_obj.parent.data
 266                                 bone_indices = dict((armature.bones[i].name, i) for i in range(len(armature.bones)))
 267                                 for g in first_obj.vertex_groups:
 268                                         if g.name in bone_indices:
 269                                                 group_index_map[g.index] = bone_indices[g.name]
 270
 271                 if self.material_tex and mesh.materials:
 272                         mesh.generate_material_uv()
 273
 274                 texunits = []
 275                 force_unit0 = False
 276                 if mesh.uv_layers and (self.export_uv!="NONE" or self.material_tex):
 277                         # Figure out which UV layers to export
 278                         if self.export_uv=="ALL":
 279                                 texunits = range(len(mesh.uv_layers))
 280                         elif self.material_tex:
 281                                 # The material UV layer is always the last one
 282                                 texunits = [len(mesh.uv_layers)-1]
 283                                 force_unit0 = True
 284                         else:
 285                                 for i, u in enumerate(mesh.uv_layers):
 286                                         if u.unit==0:
 287                                                 texunits = [i]
 288                                                 break
 289                         texunits = [(i, mesh.uv_layers[i]) for i in texunits]
 290                         texunits = [u for u in texunits if not u[1].hidden]
 291
 292                         if self.tbn_vecs:
 293                                 # TBN coordinates must be generated before vertices are split by any other layer
 294                                 uv_names = [u.name for i, u in texunits]
 295                                 if self.tbn_uvtex in uv_names:
 296                                         tbn_index = uv_names.index(self.tbn_uvtex)
 297                                         unit = texunits[tbn_index]
 298                                         del texunits[tbn_index]
 299                                         texunits.insert(0, unit)
 300
 301                         for i, u in texunits:
 302                                 if progress:
 303                                         progress.set_task("Splitting UVs", 0.35+0.3*i/len(texunits), 0.35+0.3*(i+1)/len(texunits))
 304                                 mesh.split_uv(i, progress)
 305                                 if self.tbn_vecs and u.name==self.tbn_uvtex:
 306                                         mesh.compute_uv()
 307                                         mesh.compute_tbn(i)
 308
 309                         mesh.compute_uv()
 310
 311                 strips = []
 312                 loose = mesh.faces
 313                 if self.use_strips:
 314                         if progress:
 315                                 progress.set_task("Creating strips", 0.65, 0.95)
 316                         strips, loose = self.stripify(mesh, progress)
 317
 318                 if progress:
 319                         progress.set_task("Writing file", 0.95, 1.0)
 320
 321                 from .outfile import open_output
 322                 out_file = open_output(out_file)
 323
 324                 fmt = ["NORMAL3"]
 325                 if texunits:
 326                         for i, u in texunits:
 327                                 size = str(len(mesh.vertices[0].uvs[i]))
 328                                 if u.unit==0 or force_unit0:
 329                                         fmt.append("TEXCOORD"+size)
 330                                 else:
 331                                         fmt.append("TEXCOORD%s_%d"%(size, u.unit))
 332                         if self.tbn_vecs:
 333                                 fmt += ["TANGENT3", "BINORMAL3"]
 334                 if self.export_groups:
 335                         fmt.append("ATTRIB%d_5"%(self.max_groups*2))
 336                 fmt.append("VERTEX3")
 337                 out_file.begin("vertices", *fmt)
 338                 normal = None
 339                 uvs = {}
 340                 tan = None
 341                 bino = None
 342                 group = None
 343                 for v in mesh.vertices:
 344                         if v.normal!=normal:
 345                                 out_file.write("normal3", *v.normal)
 346                                 normal = v.normal
 347                         for i, u in texunits:
 348                                 if v.uvs[i]!=uvs.get(i):
 349                                         size = str(len(v.uvs[i]))
 350                                         if u.unit==0 or force_unit0:
 351                                                 out_file.write("texcoord"+size, *v.uvs[i])
 352                                         else:
 353                                                 out_file.write("multitexcoord"+size, u.unit, *v.uvs[i])
 354                                         uvs[i] = v.uvs[i]
 355                         if self.tbn_vecs:
 356                                 if v.tan!=tan:
 357                                         out_file.write("tangent3", *v.tan)
 358                                         tan = v.tan
 359                                 if v.bino!=bino:
 360                                         out_file.write("binormal3", *v.bino)
 361                                         bino = v.bino
 362                         if self.export_groups:
 363                                 group_attr = [(group_index_map[g.group], g.weight*v.group_weight_scale) for g in v.groups[:self.max_groups]]
 364                                 while len(group_attr)<self.max_groups:
 365                                         group_attr.append((0, 0.0))
 366                                 group_attr = list(itertools.chain(*group_attr))
 367                                 if group_attr!=group:
 368                                         out_file.write("attrib%d"%len(group_attr), 5, *group_attr)
 369                                         group = group_attr
 370                         out_file.write("vertex3", *v.co)
 371                 out_file.end()
 372                 for s in strips:
 373                         out_file.begin("batch", "TRIANGLE_STRIP")
 374                         indices = []
 375                         n = 0
 376                         for v in s:
 377                                 indices.append(v.index)
 378                                 if len(indices)>=32:
 379                                         out_file.write("indices", *indices)
 380                                         indices = []
 381                         if indices:
 382                                 out_file.write("indices", *indices)
 383                         out_file.end()
 384
 385                 if loose:
 386                         out_file.begin("batch", "TRIANGLES")
 387                         for f in loose:
 388                                 for i in range(2, len(f.vertices)):
 389                                         out_file.write("indices", f.vertices[0].index, f.vertices[i-1].index, f.vertices[i].index)
 390                         out_file.end()
 391
 392                 if self.export_lines and mesh.lines:
 393                         out_file.begin("batch", "LINES")
 394                         for l in mesh.lines:
 395                                 out_file.write("indices", l.vertices[0].index, l.vertices[1].index)
 396                         out_file.end()
 397
 398                 if winding_test:
 399                         out_file.write("winding", "COUNTERCLOCKWISE")
 400
 401                 if progress:
 402                         progress.set_task("Done", 1.0, 1.0)
 403
 404                 for m in bmeshes:
 405                         bpy.data.meshes.remove(m)
 406
 407                 return mesh