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                 island_strips = []
  68                 while 1:
  69                         if not island:
  70                                 # No current island; find any unused face to start from
  71                                 queue = []
  72                                 for f in mesh.faces:
  73                                         if not f.flag:
  74                                                 f.flag = True
  75                                                 queue.append(f)
  76                                                 break
  77
  78                                 if not queue:
  79                                         break
  80
  81                                 # Find all faces connected to the first one
  82                                 while queue:
  83                                         face = queue.pop(0)
  84                                         island.append(face)
  85
  86                                         for n in f.get_neighbors():
  87                                                 if not n.flag:
  88                                                         n.flag = True
  89                                                         queue.append(n)
  90
  91                                 # Unflag the island for the next phase
  92                                 for f in island:
  93                                         f.flag = False
  94
  95                         # Find an unused face with as few unused neighbors as possible, but
  96                         # at least one.  This heuristic gives a preference to faces in corners
  97                         # or along borders of a non-closed island.
  98                         best = 5
  99                         face = None
 100                         for f in island:
 101                                 if f.flag:
 102                                         continue
 103
 104                                 score = sum(not n.flag for n in f.get_neighbors())
 105                                 if score>0 and score<best:
 106                                         face = f
 107                                         best = score
 108
 109                         if face:
 110                                 # Create a strip starting from the face.  This will flag the faces.
 111                                 strip = mesh.create_strip(face, self.max_strip_len)
 112                                 if strip:
 113                                         island_strips.append(strip)
 114                                 else:
 115                                         face.flag = True
 116                         else:
 117                                 # Couldn't find a candidate face for starting a strip, so we're
 118                                 # done with this island
 119                                 while island_strips:
 120                                         best = 0
 121                                         if cache:
 122                                                 # Find the strip that benefits the most from the current
 123                                                 # contents of the vertex cache
 124                                                 best_hits = 0
 125                                                 for i in range(len(island_strips)):
 126                                                         hits = cache.test_strip(island_strips[i])
 127                                                         if hits>best_hits:
 128                                                                 best = i
 129                                                                 best_hits = hits
 130
 131                                         strip = island_strips.pop(best)
 132                                         strips.append(strip)
 133
 134                                         if cache:
 135                                                 cache.fetch_strip(strip)
 136
 137                                 faces_done += len(island)
 138                                 if progress:
 139                                         progress.set_progress(float(faces_done)/len(mesh.faces))
 140
 141                                 # Collect any faces that weren't used in strips
 142                                 loose += [f for f in island if not f.flag]
 143                                 for f in island:
 144                                         f.flag = True
 145
 146                                 island = []
 147                                 island_strips = []
 148
 149                 if cache:
 150                         cache = VertexCache(self.cache_size)
 151                         total_hits = 0
 152
 153                 if self.use_degen_tris and strips:
 154                         big_strip = []
 155
 156                         for s in strips:
 157                                 if big_strip:
 158                                         # Generate glue elements, ensuring that the next strip begins at
 159                                         # an even position
 160                                         glue = [big_strip[-1], s[0]]
 161                                         if len(big_strip)%2:
 162                                                 glue += [s[0]]
 163
 164                                         big_strip += glue
 165                                         if cache:
 166                                                 total_hits += cache.fetch_strip(glue)
 167
 168                                 big_strip += s
 169                                 if cache:
 170                                         total_hits += cache.fetch_strip(s)
 171
 172                         for f in loose:
 173                                 # Add loose faces to the end.  This wastes space, using five
 174                                 # elements per triangle and six elements per quad.
 175                                 if len(big_strip)%2:
 176                                         order = (-1, -2, 0, 1)
 177                                 else:
 178                                         order = (0, 1, -1, -2)
 179                                 vertices = [f.vertices[i] for i in order[:len(f.vertices)]]
 180
 181                                 if big_strip:
 182                                         glue = [big_strip[-1], vertices[0]]
 183                                         big_strip += glue
 184                                         if cache:
 185                                                 total_hits += cache.fetch_strip(glue)
 186
 187                                 big_strip += vertices
 188                                 if cache:
 189                                         total_hits += cache.fetch_strip(vertices)
 190
 191                         strips = [big_strip]
 192                         loose = []
 193
 194                 return strips, loose
 195
 196         def export(self, context, out_file, objs=None, progress=None):
 197                 if objs:
 198                         objs = [(o, mathutils.Matrix()) for i in objs]
 199
 200                 if self.compound:
 201                         if objs is None:
 202                                 objs = [(o, mathutils.Matrix()) for o in context.selected_objects]
 203                         check = objs
 204                         while check:
 205                                 children = []
 206                                 for o, m in check:
 207                                         for c in o.children:
 208                                                 if c.compound:
 209                                                         children.append((c, m*c.matrix_local))
 210                                 objs += children
 211                                 check = children
 212                 elif objs is None:
 213                         objs = [(context.active_object, mathutils.Matrix())]
 214
 215                 if not objs:
 216                         raise Exception("Nothing to export")
 217                 for o, m in objs:
 218                         if o.type!="MESH":
 219                                 raise Exception("Can only export Mesh data")
 220
 221                 from .mesh import Mesh
 222                 from .util import Progress
 223
 224                 if self.show_progress:
 225                         if not progress:
 226                                 progress = Progress(context)
 227                         progress.set_task("Preparing", 0.0, 0.0)
 228                 else:
 229                         progress = None
 230
 231                 mesh = None
 232                 bmeshes = []
 233                 for o, m in objs:
 234                         bmesh = o.to_mesh(context.scene, True, "PREVIEW")
 235                         bmeshes.append(bmesh)
 236                         me = Mesh(bmesh)
 237                         me.transform(m)
 238                         if not mesh:
 239                                 mesh = me
 240                         else:
 241                                 mesh.splice(me)
 242
 243                 if progress:
 244                         progress.set_task("Smoothing", 0.05, 0.35)
 245                 if self.smoothing=="NONE":
 246                         mesh.flatten_faces()
 247                 mesh.split_smooth(progress)
 248
 249                 if self.smoothing!="BLENDER":
 250                         mesh.compute_normals()
 251
 252                 if self.export_groups:
 253                         mesh.sort_vertex_groups(self.max_groups)
 254
 255                         # Create a mapping from vertex group indices to bone indices
 256                         first_obj = objs[0][0]
 257                         group_index_map = dict((i, i) for i in range(len(first_obj.vertex_groups)))
 258                         if first_obj.parent and first_obj.parent.type=="ARMATURE":
 259                                 armature = first_obj.parent.data
 260                                 bone_indices = dict((armature.bones[i].name, i) for i in range(len(armature.bones)))
 261                                 for g in first_obj.vertex_groups:
 262                                         if g.name in bone_indices:
 263                                                 group_index_map[g.index] = bone_indices[g.name]
 264
 265                 if self.material_tex and mesh.materials:
 266                         mesh.generate_material_uv()
 267
 268                 texunits = []
 269                 force_unit0 = False
 270                 if mesh.uv_layers and (self.export_uv!="NONE" or self.material_tex):
 271                         # Figure out which UV layers to export
 272                         if self.export_uv=="ALL":
 273                                 texunits = range(len(mesh.uv_layers))
 274                         elif self.material_tex:
 275                                 # The material UV layer is always the last one
 276                                 texunits = [len(mesh.uv_layers)-1]
 277                                 force_unit0 = True
 278                         else:
 279                                 for i, u in enumerate(mesh.uv_layers):
 280                                         if u.unit==0:
 281                                                 texunits = [i]
 282                                                 break
 283                         texunits = [(i, mesh.uv_layers[i]) for i in texunits]
 284                         texunits = [u for u in texunits if not u[1].hidden]
 285
 286                         if self.tbn_vecs:
 287                                 # TBN coordinates must be generated before vertices are split by any other layer
 288                                 uv_names = [u.name for i, u in texunits]
 289                                 if self.tbn_uvtex in uv_names:
 290                                         tbn_index = uv_names.index(self.tbn_uvtex)
 291                                         unit = texunits[tbn_index]
 292                                         del texunits[tbn_index]
 293                                         texunits.insert(0, unit)
 294
 295                         for i, u in texunits:
 296                                 if progress:
 297                                         progress.set_task("Splitting UVs", 0.35+0.3*i/len(texunits), 0.35+0.3*(i+1)/len(texunits))
 298                                 mesh.split_uv(i, progress)
 299                                 if self.tbn_vecs and u.name==self.tbn_uvtex:
 300                                         mesh.compute_uv()
 301                                         mesh.compute_tbn(i)
 302
 303                         mesh.compute_uv()
 304
 305                 strips = []
 306                 loose = mesh.faces
 307                 if self.use_strips:
 308                         if progress:
 309                                 progress.set_task("Creating strips", 0.65, 0.95)
 310                         strips, loose = self.stripify(mesh, progress)
 311
 312                 if progress:
 313                         progress.set_task("Writing file", 0.95, 1.0)
 314
 315                 from .outfile import open_output
 316                 out_file = open_output(out_file)
 317
 318                 fmt = ["NORMAL3"]
 319                 if texunits:
 320                         for i, u in texunits:
 321                                 if u.unit==0 or force_unit0:
 322                                         fmt.append("TEXCOORD2")
 323                                 else:
 324                                         fmt.append("TEXCOORD2_%d"%u.unit)
 325                         if self.tbn_vecs:
 326                                 fmt += ["TANGENT3", "BINORMAL3"]
 327                 if self.export_groups:
 328                         fmt.append("ATTRIB%d_5"%(self.max_groups*2))
 329                 fmt.append("VERTEX3")
 330                 out_file.begin("vertices", *fmt)
 331                 normal = None
 332                 uvs = {}
 333                 tan = None
 334                 bino = None
 335                 group = None
 336                 for v in mesh.vertices:
 337                         if v.normal!=normal:
 338                                 out_file.write("normal3", *v.normal)
 339                                 normal = v.normal
 340                         for i, u in texunits:
 341                                 if v.uvs[i]!=uvs.get(i):
 342                                         if u.unit==0 or force_unit0:
 343                                                 out_file.write("texcoord2", *v.uvs[i])
 344                                         else:
 345                                                 out_file.write("multitexcoord2", u.unit, *v.uvs[i])
 346                                         uvs[i] = v.uvs[i]
 347                         if self.tbn_vecs:
 348                                 if v.tan!=tan:
 349                                         out_file.write("tangent3", *v.tan)
 350                                         tan = v.tan
 351                                 if v.bino!=bino:
 352                                         out_file.write("binormal3", *v.bino)
 353                                         bino = v.bino
 354                         if self.export_groups:
 355                                 group_attr = [(group_index_map[g.group], g.weight*v.group_weight_scale) for g in v.groups[:self.max_groups]]
 356                                 while len(group_attr)<self.max_groups:
 357                                         group_attr.append((0, 0.0))
 358                                 group_attr = list(itertools.chain(*group_attr))
 359                                 if group_attr!=group:
 360                                         out_file.write("attrib%d"%len(group_attr), 5, *group_attr)
 361                                         group = group_attr
 362                         out_file.write("vertex3", *v.co)
 363                 out_file.end()
 364                 for s in strips:
 365                         out_file.begin("batch", "TRIANGLE_STRIP")
 366                         indices = []
 367                         n = 0
 368                         for v in s:
 369                                 indices.append(v.index)
 370                                 if len(indices)>=32:
 371                                         out_file.write("indices", *indices)
 372                                         indices = []
 373                         if indices:
 374                                 out_file.write("indices", *indices)
 375                         out_file.end()
 376
 377                 if loose:
 378                         out_file.begin("batch", "TRIANGLES")
 379                         for f in loose:
 380                                 for i in range(2, len(f.vertices)):
 381                                         out_file.write("indices", f.vertices[0].index, f.vertices[i-1].index, f.vertices[i].index)
 382                         out_file.end()
 383
 384                 if self.export_lines and mesh.lines:
 385                         out_file.begin("batch", "LINES")
 386                         for l in mesh.lines:
 387                                 out_file.write("indices", l.vertices[0].index, l.vertices[1].index)
 388                         out_file.end()
 389
 390                 if progress:
 391                         progress.set_task("Done", 1.0, 1.0)
 392
 393                 for m in bmeshes:
 394                         bpy.data.meshes.remove(m)
 395
 396                 return mesh