Convert bones to meshes

Question

I want to use the blender built-in skeleton as a character - is there a way to convert the bones to concretes meshes?

Answer 1

I was not able to find an addon for that and as it is very close from another question. Here is an operator to do that (nearly, as the bone shape is not exactly the same).

The code is commented below. To use it, copy the code in a text view and run the script.

Then in the 3D view, select your armature, hit space and type "MeshFromArmature" and validate.

The result is a rigged mesh mimicking the armature shape.

If you want to enhance the bone shape, the code is isolated in one function 'boneGeometry' with the needed parameters.

If the comments in the code are not clear enough, please tell.

2.79 Version

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.scene.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 )

2.8 Version

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=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 )

Link to the blend file