blender/io_mspgl/export_mesh.py

   1 import itertools
   2 import bpy
   3
   4 class VertexCache:
   5         def __init__(self, size):
   6                 self.size = size
   7                 self.slots = [-1]*self.size
   8
   9         def fetch(self, v):
  10                 hit = v.index in self.slots
  11                 if hit:
  12                         self.slots.remove(v.index)
  13                 self.slots.append(v.index)
  14                 if not hit:
  15                         del self.slots[0]
  16                 return hit
  17
  18         def fetch_strip(self, strip):
  19                 hits = 0
  20                 for v in strip:
  21                         if self.fetch(v):
  22                                 hits += 1
  23                 return hits
  24
  25         def test_strip(self, strip):
  26                 hits = 0
  27                 for i in range(len(strip)):
  28                         if i>=self.size:
  29                                 break
  30                         if strip[i].index in self.slots[i:]:
  31                                 hits += 1
  32                 return hits
  33
  34
  35 class MeshExporter:
  36         def __init__(self):
  37                 self.show_progress = True
  38                 self.use_strips = True
  39                 self.use_degen_tris = False
  40                 self.max_strip_len = 1024
  41                 self.optimize_cache = True
  42                 self.cache_size = 64
  43                 self.export_lines = False
  44                 self.export_uv = "UNIT0"
  45                 self.tbn_vecs = False
  46                 self.tbn_uvtex = ""
  47                 self.compound = False
  48                 self.material_tex = False
  49                 self.smoothing = "MSPGL"
  50                 self.export_groups = False
  51                 self.max_groups = 2
  52
  53         def stripify(self, mesh, progress = None):
  54                 for f in mesh.faces:
  55                         f.flag = False
  56
  57                 faces_done = 0
  58                 strips = []
  59                 loose = []
  60
  61                 cache = None
  62                 if self.optimize_cache:
  63                         cache = VertexCache(self.cache_size)
  64
  65                 island = []
  66                 island_strips = []
  67                 while 1:
  68                         if not island:
  69                                 # No current island; find any unused face to start from
  70                                 queue = []
  71                                 for f in mesh.faces:
  72                                         if not f.flag:
  73                                                 f.flag = True
  74                                                 queue.append(f)
  75                                                 break
  76
  77                                 if not queue:
  78                                         break
  79
  80                                 # Find all faces connected to the first one
  81                                 while queue:
  82                                         face = queue.pop(0)
  83                                         island.append(face)
  84
  85                                         for n in f.get_neighbors():
  86                                                 if not n.flag:
  87                                                         n.flag = True
  88                                                         queue.append(n)
  89
  90                                 # Unflag the island for the next phase
  91                                 for f in island:
  92                                         f.flag = False
  93
  94                         # Find an unused face with as few unused neighbors as possible, but
  95                         # at least one.  This heuristic gives a preference to faces in corners
  96                         # or along borders of a non-closed island.
  97                         best = 5
  98                         face = None
  99                         for f in island:
 100                                 if f.flag:
 101                                         continue
 102
 103                                 score = sum(not n.flag for n in f.get_neighbors())
 104                                 if score>0 and score<best:
 105                                         face = f
 106                                         best = score
 107
 108                         if face:
 109                                 # Create a strip starting from the face.  This will flag the faces.
 110                                 strip = mesh.create_strip(face, self.max_strip_len)
 111                                 if strip:
 112                                         island_strips.append(strip)
 113                                 else:
 114                                         face.flag = True
 115                         else:
 116                                 # Couldn't find a candidate face for starting a strip, so we're
 117                                 # done with this island
 118                                 while island_strips:
 119                                         best = 0
 120                                         if cache:
 121                                                 # Find the strip that benefits the most from the current
 122                                                 # contents of the vertex cache
 123                                                 best_hits = 0
 124                                                 for i in range(len(island_strips)):
 125                                                         hits = cache.test_strip(island_strips[i])
 126                                                         if hits>best_hits:
 127                                                                 best = i
 128                                                                 best_hits = hits
 129
 130                                         strip = island_strips.pop(best)
 131                                         strips.append(strip)
 132
 133                                         if cache:
 134                                                 cache.fetch_strip(strip)
 135
 136                                 faces_done += len(island)
 137                                 if progress:
 138                                         progress.set_progress(float(faces_done)/len(mesh.faces))
 139
 140                                 # Collect any faces that weren't used in strips
 141                                 loose += [f for f in island if not f.flag]
 142                                 for f in island:
 143                                         f.flag = True
 144
 145                                 island = []
 146                                 island_strips = []
 147
 148                 if cache:
 149                         cache = VertexCache(self.cache_size)
 150                         total_hits = 0
 151
 152                 if self.use_degen_tris and strips:
 153                         big_strip = []
 154
 155                         for s in strips:
 156                                 if big_strip:
 157                                         # Generate glue elements, ensuring that the next strip begins at
 158                                         # an even position
 159                                         glue = [big_strip[-1], s[0]]
 160                                         if len(big_strip)%2:
 161                                                 glue += [s[0]]
 162
 163                                         big_strip += glue
 164                                         if cache:
 165                                                 total_hits += cache.fetch_strip(glue)
 166
 167                                 big_strip += s
 168                                 if cache:
 169                                         total_hits += cache.fetch_strip(s)
 170
 171                         for f in loose:
 172                                 # Add loose faces to the end.  This wastes space, using five
 173                                 # elements per triangle and six elements per quad.
 174                                 if len(big_strip)%2:
 175                                         order = (-1, -2, 0, 1)
 176                                 else:
 177                                         order = (0, 1, -1, -2)
 178                                 vertices = [f.vertices[i] for i in order[:len(f.vertices)]]
 179
 180                                 if big_strip:
 181                                         glue = [big_strip[-1], vertices[0]]
 182                                         big_strip += glue
 183                                         if cache:
 184                                                 total_hits += cache.fetch_strip(glue)
 185
 186                                 big_strip += vertices
 187                                 if cache:
 188                                         total_hits += cache.fetch_strip(vertices)
 189
 190                         strips = [big_strip]
 191                         loose = []
 192
 193                 return strips, loose
 194
 195         def export(self, context, out_file, objs=None, progress=None):
 196                 if self.compound:
 197                         if objs is None:
 198                                 objs = context.selected_objects
 199                         check = objs
 200                         while check:
 201                                 children = []
 202                                 for o in check:
 203                                         for c in o.children:
 204                                                 if c.compound:
 205                                                         children.append(c)
 206                                 objs += children
 207                                 check = children
 208                 elif objs is None:
 209                         objs = [context.active_object]
 210
 211                 if not objs:
 212                         raise Exception("Nothing to export")
 213                 for o in objs:
 214                         if o.type!="MESH":
 215                                 raise Exception("Can only export Mesh data")
 216
 217                 from .mesh import Mesh
 218                 from .util import Progress
 219
 220                 if self.show_progress:
 221                         if not progress:
 222                                 progress = Progress(context)
 223                         progress.set_task("Preparing", 0.0, 0.0)
 224                 else:
 225                         progress = None
 226
 227                 mesh = None
 228                 bmeshes = []
 229                 for o in objs:
 230                         bmesh = o.to_mesh(context.scene, True, "PREVIEW")
 231                         bmeshes.append(bmesh)
 232                         if not mesh:
 233                                 mesh = Mesh(bmesh)
 234                         else:
 235                                 mesh.splice(Mesh(bmesh))
 236
 237                 if progress:
 238                         progress.set_task("Smoothing", 0.05, 0.35)
 239                 if self.smoothing=="NONE":
 240                         mesh.flatten_faces()
 241                 mesh.split_smooth(progress)
 242
 243                 if self.smoothing!="BLENDER":
 244                         mesh.compute_normals()
 245
 246                 if self.export_groups:
 247                         mesh.sort_vertex_groups(self.max_groups)
 248
 249                         # Create a mapping from vertex group indices to bone indices
 250                         group_index_map = dict((i, i) for i in range(len(objs[0].vertex_groups)))
 251                         if objs[0].parent and objs[0].parent.type=="ARMATURE":
 252                                 armature = objs[0].parent.data
 253                                 bone_indices = dict((armature.bones[i].name, i) for i in range(len(armature.bones)))
 254                                 for g in objs[0].vertex_groups:
 255                                         if g.name in bone_indices:
 256                                                 group_index_map[g.index] = bone_indices[g.name]
 257
 258                 if self.material_tex and mesh.materials:
 259                         mesh.generate_material_uv()
 260
 261                 texunits = []
 262                 force_unit0 = False
 263                 if mesh.uv_layers and (self.export_uv!="NONE" or self.material_tex):
 264                         # Figure out which UV layers to export
 265                         if self.export_uv=="ALL":
 266                                 texunits = range(len(mesh.uv_layers))
 267                         elif self.material_tex:
 268                                 # The material UV layer is always the last one
 269                                 texunits = [len(mesh.uv_layers)-1]
 270                                 force_unit0 = True
 271                         else:
 272                                 for i, u in enumerate(mesh.uv_layers):
 273                                         if u.unit==0:
 274                                                 texunits = [i]
 275                                                 break
 276                         texunits = [(i, mesh.uv_layers[i]) for i in texunits]
 277                         texunits = [u for u in texunits if not u[1].hidden]
 278
 279                         if self.tbn_vecs:
 280                                 # TBN coordinates must be generated before vertices are split by any other layer
 281                                 uv_names = [u.name for i, u in texunits]
 282                                 if self.tbn_uvtex in uv_names:
 283                                         tbn_index = uv_names.index(self.tbn_uvtex)
 284                                         unit = texunits[tbn_index]
 285                                         del texunits[tbn_index]
 286                                         texunits.insert(0, unit)
 287
 288                         for i, u in texunits:
 289                                 if progress:
 290                                         progress.set_task("Splitting UVs", 0.35+0.3*i/len(texunits), 0.35+0.3*(i+1)/len(texunits))
 291                                 mesh.split_uv(i, progress)
 292                                 if self.tbn_vecs and u.name==self.tbn_uvtex:
 293                                         mesh.compute_uv()
 294                                         mesh.compute_tbn(i)
 295
 296                         mesh.compute_uv()
 297
 298                 strips = []
 299                 loose = mesh.faces
 300                 if self.use_strips:
 301                         if progress:
 302                                 progress.set_task("Creating strips", 0.65, 0.95)
 303                         strips, loose = self.stripify(mesh, progress)
 304
 305                 if progress:
 306                         progress.set_task("Writing file", 0.95, 1.0)
 307
 308                 from .outfile import open_output
 309                 out_file = open_output(out_file)
 310
 311                 fmt = ["NORMAL3"]
 312                 if texunits:
 313                         for i, u in texunits:
 314                                 if u.unit==0 or force_unit0:
 315                                         fmt.append("TEXCOORD2")
 316                                 else:
 317                                         fmt.append("TEXCOORD2_%d"%u.unit)
 318                         if self.tbn_vecs:
 319                                 fmt += ["TANGENT3", "BINORMAL3"]
 320                 if self.export_groups:
 321                         fmt.append("ATTRIB%d_5"%(self.max_groups*2))
 322                 fmt.append("VERTEX3")
 323                 out_file.begin("vertices", *fmt)
 324                 normal = None
 325                 uvs = {}
 326                 tan = None
 327                 bino = None
 328                 group = None
 329                 for v in mesh.vertices:
 330                         if v.normal!=normal:
 331                                 out_file.write("normal3", *v.normal)
 332                                 normal = v.normal
 333                         for i, u in texunits:
 334                                 if v.uvs[i]!=uvs.get(i):
 335                                         if u.unit==0 or force_unit0:
 336                                                 out_file.write("texcoord2", *v.uvs[i])
 337                                         else:
 338                                                 out_file.write("multitexcoord2", u.unit, *v.uvs[i])
 339                                         uvs[i] = v.uvs[i]
 340                         if self.tbn_vecs:
 341                                 if v.tan!=tan:
 342                                         out_file.write("tangent3", *v.tan)
 343                                         tan = v.tan
 344                                 if v.bino!=bino:
 345                                         out_file.write("binormal3", *v.bino)
 346                                         bino = v.bino
 347                         if self.export_groups:
 348                                 group_attr = [(group_index_map[g.group], g.weight*v.group_weight_scale) for g in v.groups[:self.max_groups]]
 349                                 while len(group_attr)<self.max_groups:
 350                                         group_attr.append((0, 0.0))
 351                                 group_attr = list(itertools.chain(*group_attr))
 352                                 if group_attr!=group:
 353                                         out_file.write("attrib%d"%len(group_attr), 5, *group_attr)
 354                                         group = group_attr
 355                         out_file.write("vertex3", *v.co)
 356                 out_file.end()
 357                 for s in strips:
 358                         out_file.begin("batch", "TRIANGLE_STRIP")
 359                         indices = []
 360                         n = 0
 361                         for v in s:
 362                                 indices.append(v.index)
 363                                 if len(indices)>=32:
 364                                         out_file.write("indices", *indices)
 365                                         indices = []
 366                         if indices:
 367                                 out_file.write("indices", *indices)
 368                         out_file.end()
 369
 370                 if loose:
 371                         out_file.begin("batch", "TRIANGLES")
 372                         for f in loose:
 373                                 for i in range(2, len(f.vertices)):
 374                                         out_file.write("indices", f.vertices[0].index, f.vertices[i-1].index, f.vertices[i].index)
 375                         out_file.end()
 376
 377                 if self.export_lines and mesh.lines:
 378                         out_file.begin("batch", "LINES")
 379                         for l in mesh.lines:
 380                                 out_file.write("indices", l.vertices[0].index, l.vertices[1].index)
 381                         out_file.end()
 382
 383                 if progress:
 384                         progress.set_task("Done", 1.0, 1.0)
 385
 386                 for m in bmeshes:
 387                         bpy.data.meshes.remove(m)
 388
 389                 return mesh