def _create_usd_skeleton(self, gltf_skin, usd_xform, usd_joint_names):
"""Creates a USD skeleton from a glTF skin
Arguments:
gltf_skin {Skin} -- gltf skin
usd_xform {Xform} -- USD Xform
Returns:
Skeleton -- USD skeleton
"""
# create skeleton
root_joints = gltf_skin.root_joints
root_joint_names = [GLTF2USDUtils.convert_to_usd_friendly_node_name(root_joint.name) for root_joint in root_joints]
skeleton = None
if len(root_joints) == 1:
skeleton = UsdSkel.Skeleton.Define(self.stage, '{0}/{1}'.format(usd_xform.GetPath(), root_joint_names[0]))
else:
skeleton = UsdSkel.Skeleton.Define(self.stage, '{0}/{1}'.format(usd_xform.GetPath(), '__root__'))
gltf_bind_transforms = [Gf.Matrix4d(*xform).GetInverse() for xform in gltf_skin.get_inverse_bind_matrices()]
gltf_rest_transforms = [GLTF2USDUtils.compute_usd_transform_matrix_from_gltf_node(joint) for joint in gltf_skin.get_joints()]
if len(root_joints) > 1:
matrix = Gf.Matrix4d()
matrix.SetIdentity()
skeleton.CreateJointsAttr().Set(usd_joint_names)
skeleton.CreateBindTransformsAttr(gltf_bind_transforms)
skeleton.CreateRestTransformsAttr(gltf_rest_transforms)
return skeleton
def test_convert_node_transform_to_rest_matrix(self):
node = self.loader.get_nodes()[0]
GLTF2USDUtils.compute_usd_transform_matrix_from_gltf_node(node)
