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