Unity Humanoid や VRM のボーン構造から、MMD の標準ボーンの構造に変更したい時がある。ボーンの名前を一致させた後に、対象のボーンを 2 つ選択して、以下のスクリプトを実行する。
Unity Humanoid や MMD 標準ボーンに合わせてリネームする方法については、「VRM のボーンのリネーム」という記事を参考にすると良い。
import bpy
def overlay_bones():
if bpy.context.mode != 'EDIT':
bpy.ops.object.mode_set(mode='EDIT')
ref_bones = bpy.context.selected_objects[0].data.edit_bones
bones = bpy.context.selected_objects[1].data.edit_bones
for bone in bones:
try:
ref_bone = ref_bones[bone.name]
bone.head = ref_bone.head
bone.tail = ref_bone.tail
except:
pass
#腕の長さをボーンの長さの基準とする
length = bones['腕.R'].length / 3
for bone in bones:
if 'センター' == bone.name:
bone.head = (0,0,0)
bone.tail = (0,0,0)
bone.head.z = length * 7
elif '両目' == bone.name:
ref_bone = ref_bones['頭']
bone.head.x = 0
bone.head.y = ref_bone.tail.y - length
bone.head.z = ref_bone.tail.z + length * 6
bone.tail.xz = bone.head.xz
bone.tail.y = bone.head.y - length
elif '足ＩＫ.L' == bone.name:
ref_bone = ref_bones['ひざ.L']
bone.head = ref_bone.tail
bone.tail.xz = bone.head.xz
bone.tail.y = bone.head.y + length
elif '足ＩＫ.R' == bone.name:
ref_bone = ref_bones['ひざ.R']
bone.head = ref_bone.tail
bone.tail.xz = bone.head.xz
bone.tail.y = bone.head.y + length
elif 'つま先ＩＫ.L' == bone.name:
ref_bone = ref_bones['足首.L']
bone.head = ref_bone.tail
bone.tail.xy = bone.head.xy
bone.tail.z = bone.head.z - length
elif 'つま先ＩＫ.R' == bone.name:
ref_bone = ref_bones['足首.R']
bone.head = ref_bone.tail
bone.tail.xy = bone.head.xy
bone.tail.z = bone.head.z - length
elif '腕捩先.L' == bone.name:
ref_bone = ref_bones['腕.L']
bone.head = ref_bone.tail
bone.tail.xy = ref_bone.tail.xy
bone.tail.z = ref_bone.head.z + length
elif '腕捩先.R' == bone.name:
ref_bone = ref_bones['腕.R']
bone.head = ref_bone.tail
bone.tail.xy = ref_bone.tail.xy
bone.tail.z = ref_bone.tail.z + length
elif '手捩先.L' == bone.name:
ref_bone = ref_bones['ひじ.L']
bone.head = ref_bone.tail
bone.tail.xy = ref_bone.tail.xy
bone.tail.z = ref_bone.head.z + length
elif '手捩先.R' == bone.name:
ref_bone = ref_bones['ひじ.R']
bone.head = ref_bone.tail
bone.tail.xy = ref_bone.tail.xy
bone.tail.z = ref_bone.tail.z + length
elif '先' in bone.name:
bone.tail.xy = bone.head.xy
bone.tail.z = bone.head.z + length
elif '腕捩.L' == bone.name:
ref_bone = ref_bones['腕.L']
bone.head = ref_bone.head * 2 / 3 + ref_bone.tail / 3
bone.tail = ref_bone.head / 3 + ref_bone.tail * 2 / 3
elif '腕捩.R' == bone.name:
ref_bone = ref_bones['腕.R']
bone.head = ref_bone.head * 2 / 3 + ref_bone.tail / 3
bone.tail = ref_bone.head / 3 + ref_bone.tail * 2 / 3
elif '手捩.L' == bone.name:
ref_bone = ref_bones['ひじ.L']
bone.head = ref_bone.head * 2 / 3 + ref_bone.tail / 3
bone.tail = ref_bone.head / 3 + ref_bone.tail * 2 / 3
elif '手捩.R' == bone.name:
ref_bone = ref_bones['ひじ.R']
bone.head = ref_bone.head * 2 / 3 + ref_bone.tail / 3
bone.tail = ref_bone.head / 3 + ref_bone.tail * 2 / 3
elif '腕捩' in bone.name and '.L' in bone.name:
ref_bone = ref_bones['腕.L']
bone.head = ref_bone.head * 2 / 3 + ref_bone.tail / 3
bone.tail.xy = bone.head.xy
bone.tail.z = bone.head.z + length
elif '腕捩' in bone.name and '.R' in bone.name:
ref_bone = ref_bones['腕.R']
bone.head = ref_bone.head * 2 / 3 + ref_bone.tail / 3
bone.tail.xy = bone.head.xy
bone.tail.z = bone.head.z + length
bpy.ops.object.mode_set(mode='OBJECT')
overlay_bones()ボーンを 2 つ選択する時は、オレンジが MMD の標準ボーンになるようにする。
ボーンの構造から自動的に位置を合わせられるスクリプトを書きたかったが、大変そうなのでやめた。