Fixed crash bug when parsing quad faces.

utils/exporters/convert_obj_threejs.py

@@ -1,839 +1,839 @@
-"""Convert Wavefront OBJ / MTL files into Three.js
-
--------------------------
-How to use this converter
--------------------------
-
-python convert_obj_threejs.py -i filename.obj -o filename.js [-a center|top|bottom]
-
-Note: by default, model is centered (middle of bounding box goes to 0,0,0).
- 
---------------------------------------------------
-How to use generated JS file in your HTML document
---------------------------------------------------
-
-    <script type="text/javascript" src="Three.js"></script>
-    <script type="text/javascript" src="ModelName.js"></script>
-    
-    ...
-    
-    <script type="text/javascript">
-        ...
-        
-        var normalizeUVsFlag = 1; // set to 1 if canvas render has missing materials
-        var geometry = new ModelName( path_to_textures );
-        var mesh = new THREE.Mesh( geometry, geometry.materials, normalizeUVsFlag );
-        
-        ...
-    </script>
-    
--------------------------------------
-Parsers based on formats descriptions
--------------------------------------
-
-    http://en.wikipedia.org/wiki/Obj
-    http://en.wikipedia.org/wiki/Material_Template_Library
-    
--------------------
-Current limitations
--------------------
-
-    - for the moment, only diffuse color and texture are used 
-      (will need to extend shaders / renderers / materials in Three)
-     
-    - models cannot have more than 65,536 vertices
-      (this comes from WebGL using just 16-bit indices,
-       could be worked around by expanding indexed
-       faces into full vertex definitions)
-       
-    - texture coordinates can be wrong in canvas renderer
-      (there is crude normalization, but it doesn't
-       work for all cases)
-       
-    - everything is using smoothing
-      (if you want flat shading for whole mesh, 
-       don't export normals, then Three will 
-       compute own normals)
-
----------------------------------------------- 
-How to get proper OBJ + MTL files with Blender
-----------------------------------------------
-
-    0. Remove default cube (press DEL and ENTER)
-    
-    1. Import / create model
-    
-    2. Select all meshes (Select -> Select All by Type -> Mesh)
-    
-    3. Export to OBJ (File -> Export -> Wavefront .obj) [*]
-        - enable following options in exporter
-            Material Groups
-            Rotate X90
-            Apply Modifiers
-            High Quality Normals
-            Copy Images
-            Selection Only
-            Objects as OBJ Objects
-            UVs
-            Normals
-            Materials
-            Edges
-            
-        - select empty folder
-        - give your exported file name with "obj" extension
-        - click on "Export OBJ" button
-        
-    4. Your model is now all files in this folder (OBJ, MTL, number of images)
-        - this converter assumes all files staying in the same folder,
-          (OBJ / MTL files use relative paths)
-          
-        - for WebGL, textures must be power of 2 sized
-
-    [*] If OBJ export fails (Blender 2.54 beta), patch your Blender installation 
-        following instructions here:
-            
-            http://www.blendernation.com/2010/09/12/blender-2-54-beta-released/
-            
-------           
-Author 
-------
-AlteredQualia http://alteredqualia.com            
-
-"""
-
-import fileinput
-import operator
-import random
-import os.path
-import getopt
-import sys
-
-# #####################################################
-# Configuration
-# #####################################################
-ALIGN = "center" # center bottom top none
-
-# default colors for debugging (each material gets one distinct color): 
-# white, red, green, blue, yellow, cyan, magenta
-COLORS = [0xffeeeeee, 0xffee0000, 0xff00ee00, 0xff0000ee, 0xffeeee00, 0xff00eeee, 0xffee00ee]
-
-# #####################################################
-# Templates
-# #####################################################
-TEMPLATE_FILE = u"""\
-// Converted from: %(fname)s
-//  vertices: %(nvertex)d
-//  faces: %(nface)d 
-//  materials: %(nmaterial)d
-//
-//  This file was generated by "convert_obj_treejs.py"
-
-var %(name)s = function ( urlbase ) {
-    var scope = this;
-
-    THREE.Geometry.call(this);
-
-    var materials = [%(materials)s];
-
-    init_materials();
-    
-    var normals = [%(normals)s];
-
-%(vertices)s
-
-%(uvs)s
-
-%(faces)s
-
-    this.computeCentroids();
-    this.computeNormals();
-    
-    function material_color( mi ) {
-        var m = materials[mi];
-        if( m.col_diffuse )
-            return (m.col_diffuse[0]*255 << 16) + (m.col_diffuse[1]*255 << 8) + m.col_diffuse[2]*255;
-        else if ( m.a_dbg_color )
-            return  m.a_dbg_color;
-        else 
-            return 0xffeeeeee;
-    }
-    
-    function v( x, y, z ) {
-        scope.vertices.push( new THREE.Vertex( new THREE.Vector3( x, y, z ) ) );
-    }
-
-    function f3( a, b, c, material ) {
-        var color = material_color(material);
-        scope.faces.push( new THREE.Face3( a, b, c, null, new THREE.Color(color), material ) );
-    }
-
-    function f4( a, b, c, d, material ) {
-        var color = material_color(material);
-        scope.faces.push( new THREE.Face4( a, b, c, d, null, new THREE.Color(color), material ) );
-    }
-
-    function f3n( a, b, c, material, n1, n2, n3 ) {
-        var color = material_color(material);
-        var n1x = normals[n1][0];
-        var n1y = normals[n1][1];
-        var n1z = normals[n1][2];
-        var n2x = normals[n2][0];
-        var n2y = normals[n2][1];
-        var n2z = normals[n2][2];
-        var n3x = normals[n3][0];
-        var n3y = normals[n3][1];
-        var n3z = normals[n3][2];
-        scope.faces.push( new THREE.Face3( a, b, c, 
-                          [new THREE.Vector3( n1x, n1y, n1z ), new THREE.Vector3( n2x, n2y, n2z ), new THREE.Vector3( n3x, n3y, n3z )], 
-                          new THREE.Color(color), material ) );
-    }
-
-    function f4n( a, b, c, d, material, n1, n2, n3, n4 ) {
-        var color = material_color(material);
-        var n1x = normals[n1][0];
-        var n1y = normals[n1][1];
-        var n1z = normals[n1][2];
-        var n2x = normals[n2][0];
-        var n2y = normals[n2][1];
-        var n2z = normals[n2][2];
-        var n3x = normals[n3][0];
-        var n3y = normals[n3][1];
-        var n3z = normals[n3][2];
-        var n4x = normals[n4][0];
-        var n4y = normals[n4][1];
-        var n4z = normals[n4][2];
-        scope.faces.push( new THREE.Face4( a, b, c, d,
-                          [new THREE.Vector3( n1x, n1y, n1z ), new THREE.Vector3( n2x, n2y, n2z ), new THREE.Vector3( n3x, n3y, n3z ), new THREE.Vector3( n4x, n4y, n4z )], 
-                          new THREE.Color(color), material ) );
-    }
-
-    function uv( u1, v1, u2, v2, u3, v3, u4, v4 ) {
-        var uv = [];
-        uv.push( new THREE.UV( u1, v1 ) );
-        uv.push( new THREE.UV( u2, v2 ) );
-        uv.push( new THREE.UV( u3, v3 ) );
-        if ( u4 && v4 ) uv.push( new THREE.UV( u4, v4 ) );
-        scope.uvs.push( uv );
-    }
-
-    function init_materials() {
-        scope.materials = [];
-        for(var i=0; i<materials.length; ++i) {
-            scope.materials[i] = create_material( materials[i], urlbase );
-        }
-    }
-    
-    function is_pow2( n ) {
-        var l = Math.log(n) / Math.LN2;
-        return Math.floor(l) == l;
-    }
-    
-    function nearest_pow2(n) {
-        var l = Math.log(n) / Math.LN2;
-        return Math.pow( 2, Math.round(l) );
-    }
-    
-    function create_material( m ) {
-        var material;
-        
-        if( m.map_diffuse && urlbase ) {
-            var texture = document.createElement( 'canvas' );
-            
-            material = new THREE.MeshBitmapUVMappingMaterial( texture );
-            var image = new Image();
-            
-            image.onload = function () {
-                
-                if ( !is_pow2(this.width) || !is_pow2(this.height) ) {
-                
-                    var w = nearest_pow2( this.width );
-                    var h = nearest_pow2( this.height );
-                    material.bitmap.width = w;
-                    material.bitmap.height = h;
-                    material.bitmap.getContext("2d").drawImage( this, 0, 0, w, h );
-                }
-                else {
-                    material.bitmap = this;
-                }
-                material.loaded = 1;
-                
-            };
-            image.src = urlbase + "/" + m.map_diffuse;
-        }
-        else if( m.col_diffuse ) {
-            var color = (m.col_diffuse[0]*255 << 16) + (m.col_diffuse[1]*255 << 8) + m.col_diffuse[2]*255;
-            material = new THREE.MeshColorFillMaterial( color, m.transparency );
-        }
-        else if( m.a_dbg_color ) {
-            material = new THREE.MeshColorFillMaterial( m.a_dbg_color );
-        }
-        else {
-            material = new THREE.MeshFaceColorFillMaterial( );
-        }
-
-        return material;
-    }
-}
-
-%(name)s.prototype = new THREE.Geometry();
-%(name)s.prototype.constructor = %(name)s;
-"""
-
-TEMPLATE_VERTEX = "\tv(%f,%f,%f);"
-
-TEMPLATE_UV3 = "\tuv(%f,%f,%f,%f,%f,%f);"
-TEMPLATE_UV4 = "\tuv(%f,%f,%f,%f,%f,%f,%f,%f);"
-
-TEMPLATE_FACE3  = "\tf3(%d,%d,%d,%d);"
-TEMPLATE_FACE4  = "\tf4(%d,%d,%d,%d,%d);"
-
-TEMPLATE_FACE3N  = "\tf3n(%d,%d,%d, %d, %d,%d,%d);"
-TEMPLATE_FACE4N  = "\tf4n(%d,%d,%d,%d, %d, %d,%d,%d,%d);"
-
-TEMPLATE_N = "[%f,%f,%f]"
-
-# #####################################################
-# Utils
-# #####################################################
-def file_exists(filename):
-    """Return true if file exists and is accessible for reading.
-    
-    Should be safer than just testing for existence due to links and 
-    permissions magic on Unix filesystems.
-    
-    @rtype: boolean
-    """
-    
-    try:
-        f = open(filename, 'r')
-        f.close()
-        return True
-    except IOError:
-        return False
-
-    
-def get_name(fname):
-    """Create model name based of filename ("path/fname.js" -> "Fname").
-    """
-    
-    return os.path.basename(fname).split(".")[0].capitalize()
-  
-def bbox(vertices):
-    """Compute bounding box of vertex array.
-    """
-    
-    if len(vertices)>0:
-        minx = maxx = vertices[0][0]
-        miny = maxy = vertices[0][1]
-        minz = maxz = vertices[0][2]
-        
-        for v in vertices[1:]:
-            if v[0]<minx:
-                minx = v[0]
-            elif v[0]>maxx:
-                maxx = v[0]
-            
-            if v[1]<miny:
-                miny = v[1]
-            elif v[1]>maxy:
-                maxy = v[1]
-
-            if v[2]<minz:
-                minz = v[2]
-            elif v[2]>maxz:
-                maxz = v[2]
-
-        return { 'x':[minx,maxx], 'y':[miny,maxy], 'z':[minz,maxz] }
-    
-    else:
-        return { 'x':[0,0], 'y':[0,0], 'z':[0,0] }
-
-def translate(vertices, t):
-    """Translate array of vertices by vector t.
-    """
-    
-    for i in xrange(len(vertices)):
-        vertices[i][0] += t[0]
-        vertices[i][1] += t[1]
-        vertices[i][2] += t[2]
-        
-def center(vertices):
-    """Center model (middle of bounding box).
-    """
-    
-    bb = bbox(vertices)
-    
-    cx = bb['x'][0] + (bb['x'][1] - bb['x'][0])/2.0
-    cy = bb['y'][0] + (bb['y'][1] - bb['y'][0])/2.0
-    cz = bb['z'][0] + (bb['z'][1] - bb['z'][0])/2.0
-    
-    translate(vertices, [-cx,-cy,-cz])
-
-def top(vertices):
-    """Align top of the model with the floor (Y-axis) and center it around X and Z.
-    """
-    
-    bb = bbox(vertices)
-    
-    cx = bb['x'][0] + (bb['x'][1] - bb['x'][0])/2.0
-    cy = bb['y'][1]
-    cz = bb['z'][0] + (bb['z'][1] - bb['z'][0])/2.0
-    
-    translate(vertices, [-cx,-cy,-cz])
-    
-def bottom(vertices):
-    """Align bottom of the model with the floor (Y-axis) and center it around X and Z.
-    """
-    
-    bb = bbox(vertices)
-    
-    cx = bb['x'][0] + (bb['x'][1] - bb['x'][0])/2.0
-    cy = bb['y'][0] 
-    cz = bb['z'][0] + (bb['z'][1] - bb['z'][0])/2.0
-    
-    translate(vertices, [-cx,cy,-cz])
-
-def normalize(v):
-    """Normalize 3d vector"""
-    
-    l = math.sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2])
-    v[0] /= l
-    v[1] /= l
-    v[2] /= l
-
-# #####################################################
-# MTL parser
-# #####################################################
-def parse_mtl(fname):
-    """Parse MTL file.
-    """
-    
-    materials = {}
-    
-    for line in fileinput.input(fname):
-        chunks = line.split()
-        if len(chunks) > 0:
-            
-            # Material start
-            # newmtl identifier
-            if chunks[0] == "newmtl" and len(chunks) == 2:
-                identifier = chunks[1]
-                if not identifier in materials:
-                    materials[identifier] = {}
-
-            # Diffuse color
-            # Kd 1.000 1.000 1.000
-            if chunks[0] == "Kd" and len(chunks) == 4:                
-                materials[identifier]["col_diffuse"] = [float(chunks[1]), float(chunks[2]), float(chunks[3])]
-
-            # Ambient color
-            # Ka 1.000 1.000 1.000
-            if chunks[0] == "Ka" and len(chunks) == 4:                
-                materials[identifier]["col_ambient"] = [float(chunks[1]), float(chunks[2]), float(chunks[3])]
-
-            # Specular color
-            # Ks 1.000 1.000 1.000
-            if chunks[0] == "Ks" and len(chunks) == 4:                
-                materials[identifier]["col_specular"] = [float(chunks[1]), float(chunks[2]), float(chunks[3])]
-
-            # Specular coefficient
-            # Ns 154.000
-            if chunks[0] == "Ns" and len(chunks) == 2:                
-                materials[identifier]["specular_coef"] = float(chunks[1])
-
-            # Transparency
-            # Tr 0.9 or d 0.9
-            if (chunks[0] == "Tr" or chunks[0] == "d") and len(chunks) == 2:                
-                materials[identifier]["transparency"] = float(chunks[1])
-
-            # Optical density
-            # Ni 1.0
-            if chunks[0] == "Ni" and len(chunks) == 2:                
-                materials[identifier]["optical_density"] = float(chunks[1])
-
-            # Diffuse texture
-            # map_Kd texture_diffuse.jpg
-            if chunks[0] == "map_Kd" and len(chunks) == 2:                
-                materials[identifier]["map_diffuse"] = chunks[1]
-
-            # Ambient texture
-            # map_Ka texture_ambient.jpg
-            if chunks[0] == "map_Ka" and len(chunks) == 2:
-                materials[identifier]["map_ambient"] = chunks[1]
-
-            # Specular texture
-            # map_Ks texture_specular.jpg
-            if chunks[0] == "map_Ks" and len(chunks) == 2:
-                materials[identifier]["map_specular"] = chunks[1]
-
-            # Alpha texture
-            # map_d texture_alpha.png
-            if chunks[0] == "map_d" and len(chunks) == 2:
-                materials[identifier]["map_alpha"] = chunks[1]
-
-            # Bump texture
-            # map_bump texture_bump.jpg or bump texture_bump.jpg
-            if (chunks[0] == "map_bump" or chunks[0] == "bump") and len(chunks) == 2:
-                materials[identifier]["map_bump"] = chunks[1]
-
-            # Illumination
-            # illum 2
-            #
-            # 0. Color on and Ambient off
-            # 1. Color on and Ambient on
-            # 2. Highlight on
-            # 3. Reflection on and Ray trace on
-            # 4. Transparency: Glass on, Reflection: Ray trace on
-            # 5. Reflection: Fresnel on and Ray trace on
-            # 6. Transparency: Refraction on, Reflection: Fresnel off and Ray trace on
-            # 7. Transparency: Refraction on, Reflection: Fresnel on and Ray trace on
-            # 8. Reflection on and Ray trace off
-            # 9. Transparency: Glass on, Reflection: Ray trace off
-            # 10. Casts shadows onto invisible surfaces
-            if chunks[0] == "illum" and len(chunks) == 2:
-                materials[identifier]["illumination"] = int(chunks[1])
-
-    return materials
-    
-# #####################################################
-# OBJ parser
-# #####################################################
-def parse_vertex(text):
-    """Parse text chunk specifying single vertex.
-    
-    Possible formats:
-        vertex index
-        vertex index / texture index
-        vertex index / texture index / normal index
-        vertex index / / normal index
-    """
-    
-    v = 0
-    t = 0
-    n = 0
-    
-    chunks = text.split("/")
-    
-    v = int(chunks[0])
-    if len(chunks) > 1:
-        if chunks[1]:
-            t = int(chunks[1])
-    if len(chunks) > 2:
-        if chunks[2]:
-            n = int(chunks[2])
-            
-    return { 'v':v, 't':t, 'n':n }
-    
-def parse_obj(fname):
-    """Parse OBJ file.
-    """
-    
-    vertices = []
-    normals = []
-    uvs = []
-    
-    faces = []
-    
-    materials = {}
-    mcounter = 0
-    mcurrent = 0
-    
-    mtllib = ""
-    
-    # current face state
-    group = 0
-    object = 0
-    smooth = 0
-    
-    for line in fileinput.input(fname):
-        chunks = line.split()
-        if len(chunks) > 0:
-            
-            # Vertices as (x,y,z) coordinates
-            # v 0.123 0.234 0.345
-            if chunks[0] == "v" and len(chunks) == 4:
-                x = float(chunks[1])
-                y = float(chunks[2])
-                z = float(chunks[3])
-                vertices.append([x,y,z])
-
-            # Normals in (x,y,z) form; normals might not be unit
-            # vn 0.707 0.000 0.707
-            if chunks[0] == "vn" and len(chunks) == 4:
-                x = float(chunks[1])
-                y = float(chunks[2])
-                z = float(chunks[3])
-                normals.append([x,y,z])
-
-            # Texture coordinates in (u,v[,w]) coordinates, w is optional
-            # vt 0.500 -1.352 [0.234]
-            if chunks[0] == "vt" and len(chunks) >= 3:
-                u = float(chunks[1])
-                v = float(chunks[2])
-                w = 0
-                if len(chunks)>3:
-                    w = float(chunks[3])
-                uvs.append([u,v,w])
-
-            # Face
-            if chunks[0] == "f" and len(chunks) >= 4:
-                vertex_index = []
-                uv_index = []
-                normal_index = []
-                
-                for v in chunks[1:]:
-                    vertex = parse_vertex(v)
-                    if vertex['v']:
-                        vertex_index.append(vertex['v'])
-                    if vertex['t']:
-                        uv_index.append(vertex['t'])
-                    if vertex['n']:
-                        normal_index.append(vertex['n'])
-                
-                faces.append({
-                    'vertex':vertex_index, 
-                    'uv':uv_index,
-                    'normal':normal_index,
-                    
-                    'material':mcurrent,
-                    'group':group, 
-                    'object':object, 
-                    'smooth':smooth,
-                    })
-    
-            # Group
-            if chunks[0] == "g" and len(chunks) == 2:
-                group = chunks[1]
-
-            # Object
-            if chunks[0] == "o" and len(chunks) == 2:
-                object = chunks[1]
-
-            # Materials definition
-            if chunks[0] == "mtllib" and len(chunks) == 2:
-                mtllib = chunks[1]
-                
-            # Material
-            if chunks[0] == "usemtl" and len(chunks) == 2:
-                material = chunks[1]
-                if not material in materials:
-                    mcurrent = mcounter
-                    materials[material] = mcounter
-                    mcounter += 1
-                else:
-                    mcurrent = materials[material]
-
-            # Smooth shading
-            if chunks[0] == "s" and len(chunks) == 2:
-                smooth = chunks[1]
-
-    return faces, vertices, uvs, normals, materials, mtllib
-    
-# #####################################################
-# Generator
-# #####################################################
-def generate_vertex(v):
-    return TEMPLATE_VERTEX % (v[0], v[1], v[2])
-    
-def generate_uv(f, uvs):
-    ui = f['uv']
-    if len(ui) == 3:
-        return TEMPLATE_UV3 % (uvs[ui[0]-1][0], 1.0 - uvs[ui[0]-1][1],
-                               uvs[ui[1]-1][0], 1.0 - uvs[ui[1]-1][1],
-                               uvs[ui[2]-1][0], 1.0 - uvs[ui[2]-1][1])
-    elif len(ui) == 4:
-        return TEMPLATE_UV4 % (uvs[ui[0]-1][0], 1.0 - uvs[ui[0]-1][1],
-                               uvs[ui[1]-1][0], 1.0 - uvs[ui[1]-1][1],
-                               uvs[ui[2]-1][0], 1.0 - uvs[ui[2]-1][1],
-                               uvs[ui[3]-1][0], 1.0 - uvs[ui[3]-1][1])
-    return ""
-    
-def generate_face(f):
-    vi = f['vertex']
-    if f["normal"]:
-        ni = f['normal']
-        if len(vi) == 3:
-            return TEMPLATE_FACE3N % (vi[0]-1, vi[1]-1, vi[2]-1, f['material'], ni[0]-1, ni[1]-1, ni[2]-1)
-        elif len(vi) == 4:
-            return TEMPLATE_FACE4N % (vi[0]-1, vi[1]-1, vi[2]-1, vi[3]-1, f['material'],  ni[0]-1, ni[1]-1, ni[2]-1, n[3]-1)
-    else:
-        if len(vi) == 3:
-            return TEMPLATE_FACE3 % (vi[0]-1, vi[1]-1, vi[2]-1, f['material'])
-        elif len(vi) == 4:
-            return TEMPLATE_FACE4 % (vi[0]-1, vi[1]-1, vi[2]-1, vi[3]-1, f['material'])
-    return ""
-
-def generate_normal(n):
-    return TEMPLATE_N % (n[0], n[1], n[2])
-
-def generate_color(i):
-    """Generate hex color corresponding to integer.
-    
-    Colors should have well defined ordering.
-    First N colors are hardcoded, then colors are random 
-    (must seed random number  generator with deterministic value 
-    before getting colors).
-    """
-    
-    if i < len(COLORS):
-        return "0x%x" % COLORS[i]
-    else:
-        return "0x%x" % (int(0xffffff * random.random()) + 0xff000000)
-        
-def value2string(v):
-    if type(v)==str and v[0] != "0":
-        return '"%s"' % v
-    return str(v)
-    
-def generate_materials(mtl, materials):
-    """Generate JS array of materials objects
-    
-    JS material objects are basically prettified one-to-one 
-    mappings of MTL properties in JSON format.
-    """
-    
-    mtl_array = []
-    for m in mtl:
-        index = materials[m]
-        
-        # add debug information
-        #  materials should be sorted according to how
-        #  they appeared in OBJ file (for the first time)
-        #  this index is identifier used in face definitions
-        mtl[m]['a_dbg_name'] = m
-        mtl[m]['a_dbg_index'] = index
-        mtl[m]['a_dbg_color'] = generate_color(index)
-        
-        mtl_raw = ",\n".join(['\t"%s" : %s' % (n, value2string(v)) for n,v in sorted(mtl[m].items())])
-        mtl_string = "\t{\n%s\n\t}" % mtl_raw
-        mtl_array.append([index, mtl_string])
-        
-    return ",\n\n".join([m for i,m in sorted(mtl_array)])
-
-def generate_mtl(materials):
-    """Generate dummy materials (if there is no MTL file).
-    """
-    
-    mtl = {}
-    for m in materials:
-        index = materials[m]
-        mtl[m] = {
-            'a_dbg_name': m,
-            'a_dbg_index': index,
-            'a_dbg_color': generate_color(index)
-        }
-    return mtl
-    
-# #####################################################
-# API
-# #####################################################
-def convert(infile, outfile):
-    """Convert infile.obj to outfile.js
-    
-    Here is where everything happens. If you need to automate conversions,
-    just import this file as Python module and call this method.
-    """
-    
-    if not file_exists(infile):
-        print "Couldn't find [%s]" % infile
-        return
-        
-    faces, vertices, uvs, normals, materials, mtllib = parse_obj(infile)
-    
-    if ALIGN == "center":
-        center(vertices)
-    elif ALIGN == "bottom":
-        bottom(vertices)
-    elif ALIGN == "top":
-        top(vertices)
-    
-    random.seed(42) # to get well defined color order for materials
-    
-    uv_string = ""
-    if len(uvs)>0:
-        uv_string = "\n".join([generate_uv(f, uvs) for f in faces])
-            
-
-    mtl = {}
-    if mtllib:
-        # create full pathname for MTL (included from OBJ)
-        path = os.path.dirname(infile)
-        fname = os.path.join(path, mtllib)
-        
-        if file_exists(fname):
-            mtl = parse_mtl(fname)
-        
-        else:
-            print "Couldn't find [%s]" % fname
-    
-    if not mtl:
-        # if there is no specified MTL or if loading failed, 
-        # generate default materials with debug colors
-        mtl = generate_mtl(materials)
-        
-    
-    text = TEMPLATE_FILE % {
-    "name"      : get_name(outfile),
-    "vertices"  : "\n".join([generate_vertex(v) for v in vertices]),
-    "faces"     : "\n".join([generate_face(f)   for f in faces]),
-    "uvs"       : uv_string,
-    "normals"   : ",".join(generate_normal(n) for n in normals),
-    
-    "materials" : generate_materials(mtl, materials),
-    
-    "fname"     : infile,
-    "nvertex"   : len(vertices),
-    "nface"     : len(faces),
-    "nmaterial" : len(materials)
-    }
-    
-    out = open(outfile, "w")
-    out.write(text)
-    out.close()
-    
-    print "%d vertices, %d faces, %d materials" % (len(vertices), len(faces), len(materials))
-        
-# #############################################################################
-# Helpers
-# #############################################################################
-def usage():
-    print "Usage: %s -i filename.obj -o filename.js [-a center|top|bottom]" % os.path.basename(sys.argv[0])
-        
-# #####################################################
-# Main
-# #####################################################
-if __name__ == "__main__":
-    
-    # get parameters from the command line
-    try:
-        opts, args = getopt.getopt(sys.argv[1:], "hi:o:a:", ["help", "input=", "output=", "align="])
-    
-    except getopt.GetoptError:
-        usage()
-        sys.exit(2)
-        
-    infile = outfile = ""
-    
-    for o, a in opts:
-        if o in ("-h", "--help"):
-            usage()
-            sys.exit()
-        
-        elif o in ("-i", "--input"):
-            infile = a
-
-        elif o in ("-o", "--output"):
-            outfile = a
-
-        elif o in ("-a", "--align"):
-            if a in ("top", "bottom", "center"):
-                ALIGN = a
-    
-    if infile == "" or outfile == "":
-        usage()
-        sys.exit(2)
-    
-    print "Converting [%s] into [%s] ..." % (infile, outfile)
-    convert(infile, outfile)
-    
+"""Convert Wavefront OBJ / MTL files into Three.js
+
+-------------------------
+How to use this converter
+-------------------------
+
+python convert_obj_threejs.py -i filename.obj -o filename.js [-a center|top|bottom]
+
+Note: by default, model is centered (middle of bounding box goes to 0,0,0).
+ 
+--------------------------------------------------
+How to use generated JS file in your HTML document
+--------------------------------------------------
+
+    <script type="text/javascript" src="Three.js"></script>
+    <script type="text/javascript" src="ModelName.js"></script>
+    
+    ...
+    
+    <script type="text/javascript">
+        ...
+        
+        var normalizeUVsFlag = 1; // set to 1 if canvas render has missing materials
+        var geometry = new ModelName( path_to_textures );
+        var mesh = new THREE.Mesh( geometry, geometry.materials, normalizeUVsFlag );
+        
+        ...
+    </script>
+    
+-------------------------------------
+Parsers based on formats descriptions
+-------------------------------------
+
+    http://en.wikipedia.org/wiki/Obj
+    http://en.wikipedia.org/wiki/Material_Template_Library
+    
+-------------------
+Current limitations
+-------------------
+
+    - for the moment, only diffuse color and texture are used 
+      (will need to extend shaders / renderers / materials in Three)
+     
+    - models cannot have more than 65,536 vertices
+      (this comes from WebGL using just 16-bit indices,
+       could be worked around by expanding indexed
+       faces into full vertex definitions)
+       
+    - texture coordinates can be wrong in canvas renderer
+      (there is crude normalization, but it doesn't
+       work for all cases)
+       
+    - everything is using smoothing
+      (if you want flat shading for whole mesh, 
+       don't export normals, then Three will 
+       compute own normals)
+
+---------------------------------------------- 
+How to get proper OBJ + MTL files with Blender
+----------------------------------------------
+
+    0. Remove default cube (press DEL and ENTER)
+    
+    1. Import / create model
+    
+    2. Select all meshes (Select -> Select All by Type -> Mesh)
+    
+    3. Export to OBJ (File -> Export -> Wavefront .obj) [*]
+        - enable following options in exporter
+            Material Groups
+            Rotate X90
+            Apply Modifiers
+            High Quality Normals
+            Copy Images
+            Selection Only
+            Objects as OBJ Objects
+            UVs
+            Normals
+            Materials
+            Edges
+            
+        - select empty folder
+        - give your exported file name with "obj" extension
+        - click on "Export OBJ" button
+        
+    4. Your model is now all files in this folder (OBJ, MTL, number of images)
+        - this converter assumes all files staying in the same folder,
+          (OBJ / MTL files use relative paths)
+          
+        - for WebGL, textures must be power of 2 sized
+
+    [*] If OBJ export fails (Blender 2.54 beta), patch your Blender installation 
+        following instructions here:
+            
+            http://www.blendernation.com/2010/09/12/blender-2-54-beta-released/
+            
+------           
+Author 
+------
+AlteredQualia http://alteredqualia.com            
+
+"""
+
+import fileinput
+import operator
+import random
+import os.path
+import getopt
+import sys
+
+# #####################################################
+# Configuration
+# #####################################################
+ALIGN = "center" # center bottom top none
+
+# default colors for debugging (each material gets one distinct color): 
+# white, red, green, blue, yellow, cyan, magenta
+COLORS = [0xffeeeeee, 0xffee0000, 0xff00ee00, 0xff0000ee, 0xffeeee00, 0xff00eeee, 0xffee00ee]
+
+# #####################################################
+# Templates
+# #####################################################
+TEMPLATE_FILE = u"""\
+// Converted from: %(fname)s
+//  vertices: %(nvertex)d
+//  faces: %(nface)d 
+//  materials: %(nmaterial)d
+//
+//  This file was generated by "convert_obj_treejs.py"
+
+var %(name)s = function ( urlbase ) {
+    var scope = this;
+
+    THREE.Geometry.call(this);
+
+    var materials = [%(materials)s];
+
+    init_materials();
+    
+    var normals = [%(normals)s];
+
+%(vertices)s
+
+%(uvs)s
+
+%(faces)s
+
+    this.computeCentroids();
+    this.computeNormals();
+    
+    function material_color( mi ) {
+        var m = materials[mi];
+        if( m.col_diffuse )
+            return (m.col_diffuse[0]*255 << 16) + (m.col_diffuse[1]*255 << 8) + m.col_diffuse[2]*255;
+        else if ( m.a_dbg_color )
+            return  m.a_dbg_color;
+        else 
+            return 0xffeeeeee;
+    }
+    
+    function v( x, y, z ) {
+        scope.vertices.push( new THREE.Vertex( new THREE.Vector3( x, y, z ) ) );
+    }
+
+    function f3( a, b, c, material ) {
+        var color = material_color(material);
+        scope.faces.push( new THREE.Face3( a, b, c, null, new THREE.Color(color), material ) );
+    }
+
+    function f4( a, b, c, d, material ) {
+        var color = material_color(material);
+        scope.faces.push( new THREE.Face4( a, b, c, d, null, new THREE.Color(color), material ) );
+    }
+
+    function f3n( a, b, c, material, n1, n2, n3 ) {
+        var color = material_color(material);
+        var n1x = normals[n1][0];
+        var n1y = normals[n1][1];
+        var n1z = normals[n1][2];
+        var n2x = normals[n2][0];
+        var n2y = normals[n2][1];
+        var n2z = normals[n2][2];
+        var n3x = normals[n3][0];
+        var n3y = normals[n3][1];
+        var n3z = normals[n3][2];
+        scope.faces.push( new THREE.Face3( a, b, c, 
+                          [new THREE.Vector3( n1x, n1y, n1z ), new THREE.Vector3( n2x, n2y, n2z ), new THREE.Vector3( n3x, n3y, n3z )], 
+                          new THREE.Color(color), material ) );
+    }
+
+    function f4n( a, b, c, d, material, n1, n2, n3, n4 ) {
+        var color = material_color(material);
+        var n1x = normals[n1][0];
+        var n1y = normals[n1][1];
+        var n1z = normals[n1][2];
+        var n2x = normals[n2][0];
+        var n2y = normals[n2][1];
+        var n2z = normals[n2][2];
+        var n3x = normals[n3][0];
+        var n3y = normals[n3][1];
+        var n3z = normals[n3][2];
+        var n4x = normals[n4][0];
+        var n4y = normals[n4][1];
+        var n4z = normals[n4][2];
+        scope.faces.push( new THREE.Face4( a, b, c, d,
+                          [new THREE.Vector3( n1x, n1y, n1z ), new THREE.Vector3( n2x, n2y, n2z ), new THREE.Vector3( n3x, n3y, n3z ), new THREE.Vector3( n4x, n4y, n4z )], 
+                          new THREE.Color(color), material ) );
+    }
+
+    function uv( u1, v1, u2, v2, u3, v3, u4, v4 ) {
+        var uv = [];
+        uv.push( new THREE.UV( u1, v1 ) );
+        uv.push( new THREE.UV( u2, v2 ) );
+        uv.push( new THREE.UV( u3, v3 ) );
+        if ( u4 && v4 ) uv.push( new THREE.UV( u4, v4 ) );
+        scope.uvs.push( uv );
+    }
+
+    function init_materials() {
+        scope.materials = [];
+        for(var i=0; i<materials.length; ++i) {
+            scope.materials[i] = create_material( materials[i], urlbase );
+        }
+    }
+    
+    function is_pow2( n ) {
+        var l = Math.log(n) / Math.LN2;
+        return Math.floor(l) == l;
+    }
+    
+    function nearest_pow2(n) {
+        var l = Math.log(n) / Math.LN2;
+        return Math.pow( 2, Math.round(l) );
+    }
+    
+    function create_material( m ) {
+        var material;
+        
+        if( m.map_diffuse && urlbase ) {
+            var texture = document.createElement( 'canvas' );
+            
+            material = new THREE.MeshBitmapUVMappingMaterial( texture );
+            var image = new Image();
+            
+            image.onload = function () {
+                
+                if ( !is_pow2(this.width) || !is_pow2(this.height) ) {
+                
+                    var w = nearest_pow2( this.width );
+                    var h = nearest_pow2( this.height );
+                    material.bitmap.width = w;
+                    material.bitmap.height = h;
+                    material.bitmap.getContext("2d").drawImage( this, 0, 0, w, h );
+                }
+                else {
+                    material.bitmap = this;
+                }
+                material.loaded = 1;
+                
+            };
+            image.src = urlbase + "/" + m.map_diffuse;
+        }
+        else if( m.col_diffuse ) {
+            var color = (m.col_diffuse[0]*255 << 16) + (m.col_diffuse[1]*255 << 8) + m.col_diffuse[2]*255;
+            material = new THREE.MeshColorFillMaterial( color, m.transparency );
+        }
+        else if( m.a_dbg_color ) {
+            material = new THREE.MeshColorFillMaterial( m.a_dbg_color );
+        }
+        else {
+            material = new THREE.MeshFaceColorFillMaterial( );
+        }
+
+        return material;
+    }
+}
+
+%(name)s.prototype = new THREE.Geometry();
+%(name)s.prototype.constructor = %(name)s;
+"""
+
+TEMPLATE_VERTEX = "\tv(%f,%f,%f);"
+
+TEMPLATE_UV3 = "\tuv(%f,%f,%f,%f,%f,%f);"
+TEMPLATE_UV4 = "\tuv(%f,%f,%f,%f,%f,%f,%f,%f);"
+
+TEMPLATE_FACE3  = "\tf3(%d,%d,%d,%d);"
+TEMPLATE_FACE4  = "\tf4(%d,%d,%d,%d,%d);"
+
+TEMPLATE_FACE3N  = "\tf3n(%d,%d,%d, %d, %d,%d,%d);"
+TEMPLATE_FACE4N  = "\tf4n(%d,%d,%d,%d, %d, %d,%d,%d,%d);"
+
+TEMPLATE_N = "[%f,%f,%f]"
+
+# #####################################################
+# Utils
+# #####################################################
+def file_exists(filename):
+    """Return true if file exists and is accessible for reading.
+    
+    Should be safer than just testing for existence due to links and 
+    permissions magic on Unix filesystems.
+    
+    @rtype: boolean
+    """
+    
+    try:
+        f = open(filename, 'r')
+        f.close()
+        return True
+    except IOError:
+        return False
+
+    
+def get_name(fname):
+    """Create model name based of filename ("path/fname.js" -> "Fname").
+    """
+    
+    return os.path.basename(fname).split(".")[0].capitalize()
+  
+def bbox(vertices):
+    """Compute bounding box of vertex array.
+    """
+    
+    if len(vertices)>0:
+        minx = maxx = vertices[0][0]
+        miny = maxy = vertices[0][1]
+        minz = maxz = vertices[0][2]
+        
+        for v in vertices[1:]:
+            if v[0]<minx:
+                minx = v[0]
+            elif v[0]>maxx:
+                maxx = v[0]
+            
+            if v[1]<miny:
+                miny = v[1]
+            elif v[1]>maxy:
+                maxy = v[1]
+
+            if v[2]<minz:
+                minz = v[2]
+            elif v[2]>maxz:
+                maxz = v[2]
+
+        return { 'x':[minx,maxx], 'y':[miny,maxy], 'z':[minz,maxz] }
+    
+    else:
+        return { 'x':[0,0], 'y':[0,0], 'z':[0,0] }
+
+def translate(vertices, t):
+    """Translate array of vertices by vector t.
+    """
+    
+    for i in xrange(len(vertices)):
+        vertices[i][0] += t[0]
+        vertices[i][1] += t[1]
+        vertices[i][2] += t[2]
+        
+def center(vertices):
+    """Center model (middle of bounding box).
+    """
+    
+    bb = bbox(vertices)
+    
+    cx = bb['x'][0] + (bb['x'][1] - bb['x'][0])/2.0
+    cy = bb['y'][0] + (bb['y'][1] - bb['y'][0])/2.0
+    cz = bb['z'][0] + (bb['z'][1] - bb['z'][0])/2.0
+    
+    translate(vertices, [-cx,-cy,-cz])
+
+def top(vertices):
+    """Align top of the model with the floor (Y-axis) and center it around X and Z.
+    """
+    
+    bb = bbox(vertices)
+    
+    cx = bb['x'][0] + (bb['x'][1] - bb['x'][0])/2.0
+    cy = bb['y'][1]
+    cz = bb['z'][0] + (bb['z'][1] - bb['z'][0])/2.0
+    
+    translate(vertices, [-cx,-cy,-cz])
+    
+def bottom(vertices):
+    """Align bottom of the model with the floor (Y-axis) and center it around X and Z.
+    """
+    
+    bb = bbox(vertices)
+    
+    cx = bb['x'][0] + (bb['x'][1] - bb['x'][0])/2.0
+    cy = bb['y'][0] 
+    cz = bb['z'][0] + (bb['z'][1] - bb['z'][0])/2.0
+    
+    translate(vertices, [-cx,cy,-cz])
+
+def normalize(v):
+    """Normalize 3d vector"""
+    
+    l = math.sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2])
+    v[0] /= l
+    v[1] /= l
+    v[2] /= l
+
+# #####################################################
+# MTL parser
+# #####################################################
+def parse_mtl(fname):
+    """Parse MTL file.
+    """
+    
+    materials = {}
+    
+    for line in fileinput.input(fname):
+        chunks = line.split()
+        if len(chunks) > 0:
+            
+            # Material start
+            # newmtl identifier
+            if chunks[0] == "newmtl" and len(chunks) == 2:
+                identifier = chunks[1]
+                if not identifier in materials:
+                    materials[identifier] = {}
+
+            # Diffuse color
+            # Kd 1.000 1.000 1.000
+            if chunks[0] == "Kd" and len(chunks) == 4:                
+                materials[identifier]["col_diffuse"] = [float(chunks[1]), float(chunks[2]), float(chunks[3])]
+
+            # Ambient color
+            # Ka 1.000 1.000 1.000
+            if chunks[0] == "Ka" and len(chunks) == 4:                
+                materials[identifier]["col_ambient"] = [float(chunks[1]), float(chunks[2]), float(chunks[3])]
+
+            # Specular color
+            # Ks 1.000 1.000 1.000
+            if chunks[0] == "Ks" and len(chunks) == 4:                
+                materials[identifier]["col_specular"] = [float(chunks[1]), float(chunks[2]), float(chunks[3])]
+
+            # Specular coefficient
+            # Ns 154.000
+            if chunks[0] == "Ns" and len(chunks) == 2:                
+                materials[identifier]["specular_coef"] = float(chunks[1])
+
+            # Transparency
+            # Tr 0.9 or d 0.9
+            if (chunks[0] == "Tr" or chunks[0] == "d") and len(chunks) == 2:                
+                materials[identifier]["transparency"] = float(chunks[1])
+
+            # Optical density
+            # Ni 1.0
+            if chunks[0] == "Ni" and len(chunks) == 2:                
+                materials[identifier]["optical_density"] = float(chunks[1])
+
+            # Diffuse texture
+            # map_Kd texture_diffuse.jpg
+            if chunks[0] == "map_Kd" and len(chunks) == 2:                
+                materials[identifier]["map_diffuse"] = chunks[1]
+
+            # Ambient texture
+            # map_Ka texture_ambient.jpg
+            if chunks[0] == "map_Ka" and len(chunks) == 2:
+                materials[identifier]["map_ambient"] = chunks[1]
+
+            # Specular texture
+            # map_Ks texture_specular.jpg
+            if chunks[0] == "map_Ks" and len(chunks) == 2:
+                materials[identifier]["map_specular"] = chunks[1]
+
+            # Alpha texture
+            # map_d texture_alpha.png
+            if chunks[0] == "map_d" and len(chunks) == 2:
+                materials[identifier]["map_alpha"] = chunks[1]
+
+            # Bump texture
+            # map_bump texture_bump.jpg or bump texture_bump.jpg
+            if (chunks[0] == "map_bump" or chunks[0] == "bump") and len(chunks) == 2:
+                materials[identifier]["map_bump"] = chunks[1]
+
+            # Illumination
+            # illum 2
+            #
+            # 0. Color on and Ambient off
+            # 1. Color on and Ambient on
+            # 2. Highlight on
+            # 3. Reflection on and Ray trace on
+            # 4. Transparency: Glass on, Reflection: Ray trace on
+            # 5. Reflection: Fresnel on and Ray trace on
+            # 6. Transparency: Refraction on, Reflection: Fresnel off and Ray trace on
+            # 7. Transparency: Refraction on, Reflection: Fresnel on and Ray trace on
+            # 8. Reflection on and Ray trace off
+            # 9. Transparency: Glass on, Reflection: Ray trace off
+            # 10. Casts shadows onto invisible surfaces
+            if chunks[0] == "illum" and len(chunks) == 2:
+                materials[identifier]["illumination"] = int(chunks[1])
+
+    return materials
+    
+# #####################################################
+# OBJ parser
+# #####################################################
+def parse_vertex(text):
+    """Parse text chunk specifying single vertex.
+    
+    Possible formats:
+        vertex index
+        vertex index / texture index
+        vertex index / texture index / normal index
+        vertex index / / normal index
+    """
+    
+    v = 0
+    t = 0
+    n = 0
+    
+    chunks = text.split("/")
+    
+    v = int(chunks[0])
+    if len(chunks) > 1:
+        if chunks[1]:
+            t = int(chunks[1])
+    if len(chunks) > 2:
+        if chunks[2]:
+            n = int(chunks[2])
+            
+    return { 'v':v, 't':t, 'n':n }
+    
+def parse_obj(fname):
+    """Parse OBJ file.
+    """
+    
+    vertices = []
+    normals = []
+    uvs = []
+    
+    faces = []
+    
+    materials = {}
+    mcounter = 0
+    mcurrent = 0
+    
+    mtllib = ""
+    
+    # current face state
+    group = 0
+    object = 0
+    smooth = 0
+    
+    for line in fileinput.input(fname):
+        chunks = line.split()
+        if len(chunks) > 0:
+            
+            # Vertices as (x,y,z) coordinates
+            # v 0.123 0.234 0.345
+            if chunks[0] == "v" and len(chunks) == 4:
+                x = float(chunks[1])
+                y = float(chunks[2])
+                z = float(chunks[3])
+                vertices.append([x,y,z])
+
+            # Normals in (x,y,z) form; normals might not be unit
+            # vn 0.707 0.000 0.707
+            if chunks[0] == "vn" and len(chunks) == 4:
+                x = float(chunks[1])
+                y = float(chunks[2])
+                z = float(chunks[3])
+                normals.append([x,y,z])
+
+            # Texture coordinates in (u,v[,w]) coordinates, w is optional
+            # vt 0.500 -1.352 [0.234]
+            if chunks[0] == "vt" and len(chunks) >= 3:
+                u = float(chunks[1])
+                v = float(chunks[2])
+                w = 0
+                if len(chunks)>3:
+                    w = float(chunks[3])
+                uvs.append([u,v,w])
+
+            # Face
+            if chunks[0] == "f" and len(chunks) >= 4:
+                vertex_index = []
+                uv_index = []
+                normal_index = []
+                
+                for v in chunks[1:]:
+                    vertex = parse_vertex(v)
+                    if vertex['v']:
+                        vertex_index.append(vertex['v'])
+                    if vertex['t']:
+                        uv_index.append(vertex['t'])
+                    if vertex['n']:
+                        normal_index.append(vertex['n'])
+                
+                faces.append({
+                    'vertex':vertex_index, 
+                    'uv':uv_index,
+                    'normal':normal_index,
+                    
+                    'material':mcurrent,
+                    'group':group, 
+                    'object':object, 
+                    'smooth':smooth,
+                    })
+    
+            # Group
+            if chunks[0] == "g" and len(chunks) == 2:
+                group = chunks[1]
+
+            # Object
+            if chunks[0] == "o" and len(chunks) == 2:
+                object = chunks[1]
+
+            # Materials definition
+            if chunks[0] == "mtllib" and len(chunks) == 2:
+                mtllib = chunks[1]
+                
+            # Material
+            if chunks[0] == "usemtl" and len(chunks) == 2:
+                material = chunks[1]
+                if not material in materials:
+                    mcurrent = mcounter
+                    materials[material] = mcounter
+                    mcounter += 1
+                else:
+                    mcurrent = materials[material]
+
+            # Smooth shading
+            if chunks[0] == "s" and len(chunks) == 2:
+                smooth = chunks[1]
+
+    return faces, vertices, uvs, normals, materials, mtllib
+    
+# #####################################################
+# Generator
+# #####################################################
+def generate_vertex(v):
+    return TEMPLATE_VERTEX % (v[0], v[1], v[2])
+    
+def generate_uv(f, uvs):
+    ui = f['uv']
+    if len(ui) == 3:
+        return TEMPLATE_UV3 % (uvs[ui[0]-1][0], 1.0 - uvs[ui[0]-1][1],
+                               uvs[ui[1]-1][0], 1.0 - uvs[ui[1]-1][1],
+                               uvs[ui[2]-1][0], 1.0 - uvs[ui[2]-1][1])
+    elif len(ui) == 4:
+        return TEMPLATE_UV4 % (uvs[ui[0]-1][0], 1.0 - uvs[ui[0]-1][1],
+                               uvs[ui[1]-1][0], 1.0 - uvs[ui[1]-1][1],
+                               uvs[ui[2]-1][0], 1.0 - uvs[ui[2]-1][1],
+                               uvs[ui[3]-1][0], 1.0 - uvs[ui[3]-1][1])
+    return ""
+    
+def generate_face(f):
+    vi = f['vertex']
+    if f["normal"]:
+        ni = f['normal']
+        if len(vi) == 3:
+            return TEMPLATE_FACE3N % (vi[0]-1, vi[1]-1, vi[2]-1, f['material'], ni[0]-1, ni[1]-1, ni[2]-1)
+        elif len(vi) == 4:
+            return TEMPLATE_FACE4N % (vi[0]-1, vi[1]-1, vi[2]-1, vi[3]-1, f['material'],  ni[0]-1, ni[1]-1, ni[2]-1, ni[3]-1)
+    else:
+        if len(vi) == 3:
+            return TEMPLATE_FACE3 % (vi[0]-1, vi[1]-1, vi[2]-1, f['material'])
+        elif len(vi) == 4:
+            return TEMPLATE_FACE4 % (vi[0]-1, vi[1]-1, vi[2]-1, vi[3]-1, f['material'])
+    return ""
+
+def generate_normal(n):
+    return TEMPLATE_N % (n[0], n[1], n[2])
+
+def generate_color(i):
+    """Generate hex color corresponding to integer.
+    
+    Colors should have well defined ordering.
+    First N colors are hardcoded, then colors are random 
+    (must seed random number  generator with deterministic value 
+    before getting colors).
+    """
+    
+    if i < len(COLORS):
+        return "0x%x" % COLORS[i]
+    else:
+        return "0x%x" % (int(0xffffff * random.random()) + 0xff000000)
+        
+def value2string(v):
+    if type(v)==str and v[0] != "0":
+        return '"%s"' % v
+    return str(v)
+    
+def generate_materials(mtl, materials):
+    """Generate JS array of materials objects
+    
+    JS material objects are basically prettified one-to-one 
+    mappings of MTL properties in JSON format.
+    """
+    
+    mtl_array = []
+    for m in mtl:
+        index = materials[m]
+        
+        # add debug information
+        #  materials should be sorted according to how
+        #  they appeared in OBJ file (for the first time)
+        #  this index is identifier used in face definitions
+        mtl[m]['a_dbg_name'] = m
+        mtl[m]['a_dbg_index'] = index
+        mtl[m]['a_dbg_color'] = generate_color(index)
+        
+        mtl_raw = ",\n".join(['\t"%s" : %s' % (n, value2string(v)) for n,v in sorted(mtl[m].items())])
+        mtl_string = "\t{\n%s\n\t}" % mtl_raw
+        mtl_array.append([index, mtl_string])
+        
+    return ",\n\n".join([m for i,m in sorted(mtl_array)])
+
+def generate_mtl(materials):
+    """Generate dummy materials (if there is no MTL file).
+    """
+    
+    mtl = {}
+    for m in materials:
+        index = materials[m]
+        mtl[m] = {
+            'a_dbg_name': m,
+            'a_dbg_index': index,
+            'a_dbg_color': generate_color(index)
+        }
+    return mtl
+    
+# #####################################################
+# API
+# #####################################################
+def convert(infile, outfile):
+    """Convert infile.obj to outfile.js
+    
+    Here is where everything happens. If you need to automate conversions,
+    just import this file as Python module and call this method.
+    """
+    
+    if not file_exists(infile):
+        print "Couldn't find [%s]" % infile
+        return
+        
+    faces, vertices, uvs, normals, materials, mtllib = parse_obj(infile)
+    
+    if ALIGN == "center":
+        center(vertices)
+    elif ALIGN == "bottom":
+        bottom(vertices)
+    elif ALIGN == "top":
+        top(vertices)
+    
+    random.seed(42) # to get well defined color order for materials
+    
+    uv_string = ""
+    if len(uvs)>0:
+        uv_string = "\n".join([generate_uv(f, uvs) for f in faces])
+            
+
+    mtl = {}
+    if mtllib:
+        # create full pathname for MTL (included from OBJ)
+        path = os.path.dirname(infile)
+        fname = os.path.join(path, mtllib)
+        
+        if file_exists(fname):
+            mtl = parse_mtl(fname)
+        
+        else:
+            print "Couldn't find [%s]" % fname
+    
+    if not mtl:
+        # if there is no specified MTL or if loading failed, 
+        # generate default materials with debug colors
+        mtl = generate_mtl(materials)
+        
+    
+    text = TEMPLATE_FILE % {
+    "name"      : get_name(outfile),
+    "vertices"  : "\n".join([generate_vertex(v) for v in vertices]),
+    "faces"     : "\n".join([generate_face(f)   for f in faces]),
+    "uvs"       : uv_string,
+    "normals"   : ",".join(generate_normal(n) for n in normals),
+    
+    "materials" : generate_materials(mtl, materials),
+    
+    "fname"     : infile,
+    "nvertex"   : len(vertices),
+    "nface"     : len(faces),
+    "nmaterial" : len(materials)
+    }
+    
+    out = open(outfile, "w")
+    out.write(text)
+    out.close()
+    
+    print "%d vertices, %d faces, %d materials" % (len(vertices), len(faces), len(materials))
+        
+# #############################################################################
+# Helpers
+# #############################################################################
+def usage():
+    print "Usage: %s -i filename.obj -o filename.js [-a center|top|bottom]" % os.path.basename(sys.argv[0])
+        
+# #####################################################
+# Main
+# #####################################################
+if __name__ == "__main__":
+    
+    # get parameters from the command line
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], "hi:o:a:", ["help", "input=", "output=", "align="])
+    
+    except getopt.GetoptError:
+        usage()
+        sys.exit(2)
+        
+    infile = outfile = ""
+    
+    for o, a in opts:
+        if o in ("-h", "--help"):
+            usage()
+            sys.exit()
+        
+        elif o in ("-i", "--input"):
+            infile = a
+
+        elif o in ("-o", "--output"):
+            outfile = a
+
+        elif o in ("-a", "--align"):
+            if a in ("top", "bottom", "center"):
+                ALIGN = a
+    
+    if infile == "" or outfile == "":
+        usage()
+        sys.exit(2)
+    
+    print "Converting [%s] into [%s] ..." % (infile, outfile)
+    convert(infile, outfile)
+