A Blender Script to Convert any Rig to Mesh

RigToMeshBlender.py

import bpy
import mathutils
from mathutils import Vector
from math import *

def CreateMesh():

    obj = bpy.context.active_object

    if obj == None:
        print( "No selection" )
    elif obj.type != 'ARMATURE':
        print( "Armature expected" )
    else:
        processArmature( bpy.context, obj )

#Create the base object from the armature
def meshFromArmature( arm ):
    name = arm.name + "_mesh"
    meshData = bpy.data.meshes.new( name + "Data" )
    meshObj = bpy.data.objects.new( name, meshData )
    meshObj.matrix_world = arm.matrix_world.copy()
    return meshObj

#Create the bone geometry (vertices and faces)
def boneGeometry( l1, l2, x, z, baseSize, l1Size, l2Size, base ):
    x1 = x * baseSize * l1Size
    z1 = z * baseSize * l1Size

#    x2 = x * baseSize * l2Size
#    z2 = z * baseSize * l2Size

    x2 = Vector( (0, 0, 0) )
    z2 = Vector( (0, 0, 0) )

    verts = [
        l1 - x1 + z1,
        l1 + x1 + z1,
        l1 - x1 - z1,
        l1 + x1 - z1,
        l2 - x2 + z2,
        l2 + x2 + z2,
        l2 - x2 - z2,
        l2 + x2 - z2
        ]

    faces = [
        (base+3, base+1, base+0, base+2),
        (base+6, base+4, base+5, base+7),
        (base+4, base+0, base+1, base+5),
        (base+7, base+3, base+2, base+6),
        (base+5, base+1, base+3, base+7),
        (base+6, base+2, base+0, base+4)
        ]

    return verts, faces

#Process the armature, goes through its bones and creates the mesh
def processArmature(context, arm, genVertexGroups = True):
    print("processing armature {0}".format(arm.name))

    #Creates the mesh object
    meshObj = meshFromArmature( arm )
    context.collection.objects.link( meshObj )

    verts = []
    edges = []
    faces = []
    vertexGroups = {}

    bpy.ops.object.mode_set(mode='EDIT')

    try:
        #Goes through each bone
        for editBone in [b for b in arm.data.edit_bones if b.use_deform]:
            boneName = editBone.name
            print( boneName )
            poseBone = arm.pose.bones[boneName]

            #Gets edit bone informations
            editBoneHead = editBone.head
            editBoneTail = editBone.tail
            editBoneVector = editBoneTail - editBoneHead
            editBoneSize = editBoneVector.dot( editBoneVector )
            editBoneRoll = editBone.roll
            editBoneX = editBone.x_axis
            editBoneZ = editBone.z_axis
            editBoneHeadRadius = editBone.head_radius
            editBoneTailRadius = editBone.tail_radius

            #Creates the mesh data for the bone
            baseIndex = len(verts)
            baseSize = sqrt( editBoneSize )
            newVerts, newFaces = boneGeometry( editBoneHead, editBoneTail, editBoneX, editBoneZ, baseSize, editBoneHeadRadius, editBoneTailRadius, baseIndex )

            verts.extend( newVerts )
            faces.extend( newFaces )

            #Creates the weights for the vertex groups
            vertexGroups[boneName] = [(x, 1.0) for x in range(baseIndex, len(verts))]

        #Assigns the geometry to the mesh
        meshObj.data.from_pydata(verts, edges, faces)

    except:
        bpy.ops.object.mode_set(mode='OBJECT')
    else:
        bpy.ops.object.mode_set(mode='OBJECT')

    #Assigns the vertex groups
    if genVertexGroups:
        for name, vertexGroup in vertexGroups.items():
            groupObject = meshObj.vertex_groups.new(name)
            for (index, weight) in vertexGroup:
                groupObject.add([index], weight, 'REPLACE')

    #Creates the armature modifier
    modifier = meshObj.modifiers.new('ArmatureMod', 'ARMATURE')
    modifier.object = arm
    modifier.use_bone_envelopes = False
    modifier.use_vertex_groups = True

    meshObj.data.update()

    return meshObj

class MeshFromArmatureOperator(bpy.types.Operator):
    bl_idname = "wm.hello_world"
    bl_label = "MeshFromArmatureOperator"

    def execute(self, context):
        CreateMesh()
        return {'FINISHED'}

bpy.utils.register_class(MeshFromArmatureOperator)