Collada Exporter for Second Life - Blender Addon

This python script is a replacement for the Blender's native Collada exporter made in C++. The main goal was to fix issues related to exporting static mesh objects including textures to the Second Life grid. Also, thanks to the python, this exporter can be easily modified/maintained without the need to go into Blender's source code and recompiling Blender.

ui-panel.png

Motivation

Recently, I've noticed that the default Collada exporter in Blender (2.78) has some problems to export textured objects for usage in Second Life. Particularly, I've reported these two issues:

These issues prevent to quickly upload larger scenes (like a whole house) including all baked textures to SL and you need to apply textures by hand after upload, which is time wasting especially when you do many uploads to test your builds.

I wanted to try to fix these issues. But alas the default Collada exporter is made in C++ and I didn't want to recompile whole Blender. So, I decided to write my own Python based exporter that would work as an addon.

Notes

  • Export static mesh objects to Collada (.dae), including images assigned to the active UV layer.
  • Tested with Firestorm Viewer for Second Life and InWorldz.
  • Requires python collada module https://github.com/pycollada/pycollada. Pycollada is not a part of official Blender, so must be installed into Blender's folder (eg. Blender/2.78/scripts/modules)

ChangeLog

Version 0.2 (17.05.2017)
  • Objects (geometry nodes) are sorted by name now
Version 0.1 (12.05.2017)
  • Initial release

Download

blender-addons/collada-exporter-sl/0.2/ColladaExporterSL.py (Source)

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
#-------------------------------------------------------------------------------
#                Collada Exporter for Second Life - Blender Addon
#
# - Export static mesh objects to Collada (.dae), including images assigned to
#   the active UV layer. Tested with Firestorm Viewer for Second Life.
#
# - Requires python collada module https://github.com/pycollada/pycollada
# - Pycollada is not part of official Blender, so must be installed into
#   Blender's folder (eg. Blender/2.78/scripts/modules)
#
# Version: 0.2
# Revised: 17.05.2017
# Author: Miki (Meshlogic)
#-------------------------------------------------------------------------------
bl_info = {
    "name": "Collada Exporter SL",
    "author": "Miki (Meshlogic)",
    "category": "Import-Export",
    "description": "Export static mesh objects to Collada (.dae), including images assigned to the active UV layer. Tested with Firestorm Viewer for Second Life.",
    "location": "File > Export",
    "version": (0, 2),
    "blender": (2, 78, 0)
}

import bpy
import bpy_extras.io_utils as io_utils
import bmesh
import os
import re
import time
import numpy as np
import xml.etree.ElementTree as ET
from bpy.props import *
from bpy.types import Menu, Operator, Panel, UIList
from collada import *


#-------------------------------------------------------------------------------
# ColladaExporter OPERATOR
#-------------------------------------------------------------------------------
class ColladaExporter_OT(Operator, io_utils.ExportHelper):
    bl_idname = "export_mesh.collada_sl"
    bl_label = "Export Collada for SL"
    bl_description = "Export selected static mesh objects to Collada"
    bl_options = {'PRESET'}

    #--- Collada file extension
    filename_ext = ".dae"

    #--- Material props
    use_mat_color = BoolProperty(
            name = "Use Material Colors",
            description = "Use material diffuse color if no UV image included",
            default = True)

    use_uv_image = BoolProperty(
            name = "Include UV Images",
            description = "Include images assigned to the active UV layer",
            default = True)

    use_relative_path = BoolProperty(
            name = "Relative Path",
            description = "Use relative or absolute path for images",
            default = True)

    copy_images = BoolProperty(
            name = "Copy Images",
            description = "Copy images to subdir in the export folder",
            default = False)

    #--- Mesh props
    apply_modifiers = BoolProperty(
            name = "Apply Modifiers (View)",
            description = "Apply modifiers (view mode)",
            default = True)

    triangulate = BoolProperty(
            name = "Triangulate",
            description = "Triangulate mesh faces for export",
            default = False)

    round_values = BoolProperty(
            name = "Round Values",
            description = "Round values (vertex and normal coords) to given decimal places",
            default = False)

    round_decimals = IntProperty(
            name = "Decimals",
            description = "Round values (vertex and normal coords) to given decimal places",
            min = 3, max = 9,
            default = 6)

    #--- Draw properties in export dialog
    def draw(self, context):
        layout = self.layout

        box = layout.box()
        row = box.row()
        row.label("Material Image Options:", icon='TEXTURE')
        row = box.row()
        row.prop(self, "use_mat_color")
        row = box.row()
        row.prop(self, "use_uv_image")
        row = box.row()
        row.prop(self, "use_relative_path")
        row = box.row()
        row.prop(self, "copy_images")

        box = layout.box()
        row = box.row()
        row.label("Mesh Options:", icon='MESH_DATA')
        row = box.row()
        row.prop(self, "apply_modifiers")
        row = box.row()
        row.prop(self, "triangulate")
        row = box.row(True)
        row.prop(self, "round_values")
        row.prop(self, "round_decimals")

    #--- Execute file export
    def execute(self, context):

        # Properties as a dictionary (incl. selected filepath from file dialog)
        kwargs = self.as_keywords()

        # Init ColladaExporter object and execute export
        collada_ex = ColladaExporter(context, **kwargs)
        info = collada_ex.export()

        self.report({'INFO'}, info)
        return {'FINISHED'}


#-------------------------------------------------------------------------------
# Misc Functions
#-------------------------------------------------------------------------------
# Convert list/tuple items to string separated by sep
def list2str(items, sep):
    return sep.join(map(str, items))


#-------------------------------------------------------------------------------
# COLLADA EXPORTER CLASS
#-------------------------------------------------------------------------------
class ColladaExporter:

    def __init__(self, context, **kwargs):

        # Collada file export path
        self.export_path = kwargs["filepath"]
        self.export_dir  = os.path.dirname(self.export_path)

        # Directory of this blend file
        self.source_dir = os.path.dirname(bpy.data.filepath)

        # Export options
        self.use_mat_color     = kwargs["use_mat_color"]
        self.use_uv_image      = kwargs["use_uv_image"]
        self.use_relative_path = kwargs["use_relative_path"]
        self.copy_images       = kwargs["copy_images"]
        self.apply_modifiers   = kwargs["apply_modifiers"]
        self.triangulate       = kwargs["triangulate"]
        self.round_values      = kwargs["round_values"]
        self.round_decimals    = kwargs["round_decimals"]

        # Init Collada object for export
        self.collada = Collada(validate_output=True)
        self.scene_nodes = []

        # Collada Asset Info
        self.collada.assetInfo.upaxis = 'Z_UP'
        self.collada.assetInfo.unitname = "meter"
        self.collada.assetInfo.unitmeter = 1.0
        cont = asset.Contributor(
                "Blender %s" % list2str(bpy.app.version, "."),
                "Addon: %s %s" % (bl_info["name"], list2str(bl_info["version"], ".")),
                "Applly Modifiers: %s, Triangulate: %s" % (self.apply_modifiers, self.triangulate),
                )
        self.collada.assetInfo.contributors.append(cont)


    #---------------------------------------------------------------------------
    # EXPORT
    #---------------------------------------------------------------------------
    def export(self):

        #--- Exit edit mode before exporting
        if bpy.ops.object.mode_set.poll():
            bpy.ops.object.mode_set(mode='OBJECT')

        #--- Measure script execution time
        start_time = time.time()

        #--- Export all selected objects (sorted by name)
        obj_list = bpy.context.selected_objects
        obj_list.sort(key = lambda obj : obj.name)

        for obj in obj_list:
            self.export_object(obj)

        #--- Finish scene nodes
        c_scene = scene.Scene("Scene", self.scene_nodes)
        self.collada.scenes.append(c_scene)
        self.collada.scene = c_scene

        #--- Write Collada to file
        self.collada.write(self.export_path)

        #--- Sort XML to fix upload to SL
        self.sortxml()

        #--- Print and return info text
        info = "%d objects saved to '%s' (%.3fsec)" %\
                (len(bpy.context.selected_objects), self.export_path, time.time()-start_time)
        print(info)
        return info


    #---------------------------------------------------------------------------
    # IDNAME - Format name strings for Collada ids
    #---------------------------------------------------------------------------
    def idname(self, str):
        return re.sub("\.", "_", str) # Replace any dot in the string


    #---------------------------------------------------------------------------
    # ADD COLLADA IMAGE
    # - Add image to collada.images and return the CImage object
    # - Copy image to a subdir in the export dir if desired
    #---------------------------------------------------------------------------
    def add_collada_image(self, img):

        #--- Add image to collada.images
        if img.name not in self.collada.images:

            #--- Copy image to a subdir in the export dir
            if self.copy_images:

                # Image source path and basename
                img_sourcepath = bpy.path.abspath(img.filepath)
                img_basename = bpy.path.basename(img_sourcepath)

                # Copy image to subdir in export dir
                export_filename = bpy.path.display_name_from_filepath(self.export_path)
                subdir = export_filename + "_textures"

                img_destpath = os.path.join(self.export_dir, subdir, img_basename)
                copy_set = {(img_sourcepath, img_destpath)}
                io_utils.path_reference_copy(copy_set)

                # Relative path to the copied image
                path = io_utils.path_reference(img_destpath, self.source_dir, self.export_dir, 'RELATIVE')

            #--- Reference image where it is
            else:
                if self.use_relative_path:
                    path_mode = 'RELATIVE'
                else:
                    path_mode = 'ABSOLUTE'
                path = io_utils.path_reference(img.filepath, self.source_dir, self.export_dir, path_mode)

            #--- Create and add CImage object
            c_img = material.CImage(img.name, path)
            self.collada.images.append(c_img)

        #--- Image already added to collada.images
        else:
            c_img = self.collada.images[img.name]

        return c_img


    #---------------------------------------------------------------------------
    # ADD COLLADA VOIDMAT
    # - Add this material in case of empty or no material slot
    #---------------------------------------------------------------------------
    def add_collada_voidmat(self, name):

        # Collada material effect
        c_effect = material.Effect(name +"-effect", [], 'phong',
                diffuse = (0.5,0.5,0.5,1.0),
                ambient = (0.25,0.25,0.25,1.0),
                specular = (1.0,1.0,1.0,1.0),
                shininess = 50.0)
        self.collada.effects.append(c_effect)

        # Collada material
        c_mat = material.Material(name +"-material", name, c_effect)
        self.collada.materials.append(c_mat)
        return scene.MaterialNode(name +"-material", c_mat, inputs=[])


    #---------------------------------------------------------------------------
    # ADD COLLADA MATERIALS
    # - Add object materials to collada.materials and collada.effects
    #---------------------------------------------------------------------------
    def add_collada_materials(self, obj, me):
        material_nodes = []

        #--- Get active uv map layer and texture
        uvlayer = me.uv_layers.active
        if uvlayer:
            uvtex = me.uv_textures[uvlayer.name]

        # [1] No material slot - Add void material
        if len(me.materials) == 0:
            c_matnode = self.add_collada_voidmat(self.idname(obj.name) +"_voidmat_0")
            material_nodes.append(c_matnode)
            return material_nodes

        # [2] Go trough all slots in object materials
        for i, mat in enumerate(me.materials):

            #--- Empty material slot - Add void material
            if mat == None:
                c_matnode = self.add_collada_voidmat(self.idname(obj.name) +"_voidmat_"+ str(i))
                material_nodes.append(c_matnode)
                continue

            #--- Look for uv image assigned to the given material and uv face
            img = None
            if self.use_uv_image and uvlayer:
                for f in me.polygons:
                    if f.material_index == i:
                        img = uvtex.data[f.index].image     # Get image assigned to the uv face
                        c_img = self.add_collada_image(img) # Add image to collada images
                        break

            #--- Include image map in the material effect
            if img:
                c_surface = material.Surface(img.name +"-surface", c_img, format=None)
                c_sampler = material.Sampler2D(img.name +"-sampler", c_surface)
                params_list = [c_sampler, c_surface]
                inputs_list = [(uvlayer.name, 'TEXCOORD', '0')]
                diffuse_map = material.Map(c_sampler, uvlayer.name)

            #--- No image map for the material effect
            else:
                params_list = []
                inputs_list = []
                diffuse_color = list(mat.diffuse_color) + [1.0]
                diffuse_map = np.around(diffuse_color,6) if self.use_mat_color else (1.0,1.0,1.0,1.0)

            #--- Add material effect to collada.effects
            c_name = self.idname(obj.name) +"_"+ self.idname(mat.name)
            c_effect = material.Effect(c_name +"-effect", params_list, 'phong',
                    diffuse = diffuse_map,
                    ambient = (.25,.25,.25,1.0),
                    specular = (1.0,1.0,1.0,1.0),
                    shininess = 50.0)
            self.collada.effects.append(c_effect)

            #--- Add material to collada.materials
            c_mat = material.Material(c_name +"-material", c_name, c_effect)
            c_matnode = scene.MaterialNode(c_name +"-material", c_mat, inputs=inputs_list)
            self.collada.materials.append(c_mat)
            material_nodes.append(c_matnode)

        #--- Return scene.MaterialNode for each material
        return material_nodes


    #---------------------------------------------------------------------------
    # EXPORT OBJECT
    #---------------------------------------------------------------------------
    def export_object(self, obj):
        cs = bpy.context.scene

        #-----------------------------------------------------------------------
        # Prepare object's mesh data (me)
        #-----------------------------------------------------------------------
        # Create mesh for export & apply modifiers if desired
        me = obj.to_mesh(cs, self.apply_modifiers, 'PREVIEW')

        # Triangulate mesh if desired
        if self.triangulate:
            bm = bmesh.new()
            bm.from_mesh(me)
            bmesh.ops.triangulate(bm, faces=bm.faces)
            bm.to_mesh(me)
            bm.free()

        #-----------------------------------------------------------------------
        # Material & effect nodes for each object's material
        #-----------------------------------------------------------------------
        material_nodes = self.add_collada_materials(obj, me)

        #-----------------------------------------------------------------------
        # Source list for vertex coords
        #-----------------------------------------------------------------------
        verts_srcid = self.idname(obj.name) + "-verts"
        verts_co = np.array([co for v in me.vertices for co in v.co])
        if self.round_values:
            verts_co = np.round(verts_co, self.round_decimals)
        verts_src = source.FloatSource(verts_srcid, verts_co, ('X', 'Y', 'Z'))

        #-----------------------------------------------------------------------
        # Source list for normals
        #-----------------------------------------------------------------------
        normals_srcid = self.idname(obj.name) + "-normals"
        normals = []

        for f in me.polygons:
            # Smooth shaded face - use vertex normals
            if f.use_smooth:
                for v_id in f.vertices:
                    v = me.vertices[v_id]
                    normals.extend(v.normal)
            # Flat shaded face - use face normal for each polygon vert
            else:
                for v_id in f.vertices:
                    normals.extend(f.normal)

        normals = np.array(normals)
        if self.round_values:
            normals = np.round(normals, self.round_decimals)

        normals_src = source.FloatSource(normals_srcid, normals, ('X', 'Y', 'Z'))
        sources = [verts_src, normals_src]

        #-----------------------------------------------------------------------
        # Source list for the active UV map texture coords
        #-----------------------------------------------------------------------
        uvlayer = me.uv_layers.active
        if uvlayer:
            tex_srcid = self.idname(obj.name) + "-tex-" + uvlayer.name
            tex_uv = []

            for f in me.polygons:
                for loop_id in range(f.loop_start, f.loop_start + f.loop_total):
                    tex_uv.extend([x for x in uvlayer.data[loop_id].uv])

            tex_uv = np.array(tex_uv)
            if self.round_values:
                tex_uv = np.round(tex_uv, self.round_decimals)

            tex_src = source.FloatSource(tex_srcid, tex_uv, ('S', 'T'))
            sources.append(tex_src)

        #-----------------------------------------------------------------------
        # Geometry node for this object incl. source lists
        #-----------------------------------------------------------------------
        c_geom = geometry.Geometry(self.collada, self.idname(obj.name)+"-geom", self.idname(obj.name), sources)

        #-----------------------------------------------------------------------
        # Create Polylist for each material
        #-----------------------------------------------------------------------
        for i, matnode in enumerate(material_nodes):

            #--- Input list to define data binding to the source lists
            inlist = source.InputList()
            inlist.addInput(0, 'VERTEX', '#'+verts_srcid)
            inlist.addInput(1, 'NORMAL', '#'+normals_srcid)
            if uvlayer:
                inlist.addInput(1, 'TEXCOORD', '#'+tex_srcid, set=0)

            #--- List of indicies to the source lists for each face f, for each vert v
            indices = []
            vcounts = []
            n_id = 0
            for f in me.polygons:
                if f.material_index == i:
                    vcounts.extend([len(f.vertices)])
                    for v_id in f.vertices:
                        indices.extend([v_id, n_id])
                        n_id += 1
                else:
                    for v_id in f.vertices:
                        n_id += 1

            #--- Bind polylist with existing material node
            material_id = matnode.symbol

            #--- Append polylist to geometry
            c_poly = c_geom.createPolylist(np.array(indices), np.array(vcounts), inlist, material_id)
            c_geom.primitives.append(c_poly)

        #-----------------------------------------------------------------------
        # Create scene node for this object
        #-----------------------------------------------------------------------
        self.collada.geometries.append(c_geom)
        c_geom_node = scene.GeometryNode(c_geom, material_nodes)

        #--- Object transformation matrix
        matrix = np.array(obj.matrix_world).flatten()
        if self.round_values:
            matrix = np.round(matrix, self.round_decimals)
        c_matrix = scene.MatrixTransform(matrix)

        #--- Scene node
        c_node = scene.Node(self.idname(obj.name), children=[c_matrix, c_geom_node])
        self.scene_nodes.append(c_node)

        #--- Clean up mesh used for export
        bpy.data.meshes.remove(me)


    #---------------------------------------------------------------------------
    # Sort XML nodes to fix Second Life upload
    # - With the default sorting, SL fails to upload textures
    # - newparam/surface node must be before newparam/sampler2D for each effect
    #---------------------------------------------------------------------------
    def sortxml(self):

        #--- Load Collada XML file
        tree = ET.parse(self.export_path)
        root = tree.getroot()

        # Collada namespace
        ns = {'ns':'http://www.collada.org/2005/11/COLLADASchema'}

        # Get node tag without namespace
        gettag = lambda node : re.sub("{.*}", "", node.tag)

        #-----------------------------------------------------------------------
        # Re-order root nodes
        #-----------------------------------------------------------------------
        root_order = [
            'asset',
            'library_images',
            'library_effects',
            'library_materials',
            'library_geometries',
            'library_visual_scenes',
            'scene']

        root[:] = sorted(root, key = lambda root : root_order.index(gettag(root)))

        #-----------------------------------------------------------------------
        # Reverse sort of effect nodes newparam/surface and newparam/sampler2D
        #-----------------------------------------------------------------------
        for effect in root.findall('.//ns:effect/ns:profile_COMMON', ns):

            # Find and remove newparam nodes from the tree
            newparam = effect.findall("ns:newparam", ns)
            for item in newparam:
                effect.remove(item)

            # Insert sorted newparam nodes
            # <surface> node must be before <sampler2D>, thus reverse order
            newparam = sorted(newparam, key = lambda newparam : newparam.get('sid'), reverse=True)

            for i, item in enumerate(newparam):
                effect.insert(i, newparam[i])

        #--- Write XML to file
        spath = os.path.splitext(self.export_path)
        #tree.write(spath[0] +"_sortxml"+ spath[1])
        tree.write(self.export_path)


#-------------------------------------------------------------------------------
# MENU
#-------------------------------------------------------------------------------
def menu_export(self, context):
    self.layout.operator(ColladaExporter_OT.bl_idname, text="Collada for SL (.dae)")


#-------------------------------------------------------------------------------
# REGISTER/UNREGISTER ADDON CLASSES
#-------------------------------------------------------------------------------
def register():
    bpy.utils.register_module(__name__)
    bpy.types.INFO_MT_file_export.prepend(menu_export)

def unregister():
    bpy.utils.unregister_module(__name__)
    bpy.types.INFO_MT_file_export.remove(menu_export)

if __name__ == "__main__":
    register()

Comments

Comments powered by Disqus