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