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