import omni.usd
from pxr import Usd, Gf
import typing
def get_world_transform_xform(prim: Usd.Prim) -> typing.Tuple[Gf.Vec3d, Gf.Rotation, Gf.Vec3d]:
"""
Get the local transformation of a prim using omni.usd.get_world_transform_matrix().
See https://docs.omniverse.nvidia.com/kit/docs/omni.usd/latest/omni.usd/omni.usd.get_world_transform_matrix.html
Args:
prim: The prim to calculate the world transformation.
Returns:
A tuple of:
- Translation vector.
- Rotation quaternion, i.e. 3d vector plus angle.
- Scale vector.
"""
world_transform: Gf.Matrix4d = omni.usd.get_world_transform_matrix(prim)
translation: Gf.Vec3d = world_transform.ExtractTranslation()
rotation: Gf.Rotation = world_transform.ExtractRotation()
scale: Gf.Vec3d = Gf.Vec3d(*(v.GetLength() for v in world_transform.ExtractRotationMatrix()))
return translation, rotation, scale
#############
# Full Usage
#############
import omni.kit.commands
# Create an Xform with a Cube Prim as it's Child
omni.kit.commands.execute('CreatePrimWithDefaultXform',
prim_type='Xform',
attributes={},
select_new_prim=True)
omni.kit.commands.execute('TransformMultiPrimsSRTCpp',
count=1,
paths=['/World/Xform'],
new_translations=[100, 0, 0],
new_rotation_eulers=[0, 50 ,0],
new_rotation_orders=[0, 1, 2],
new_scales=[5, 5, 5],
old_translations=[0.0, 0.0, 0.0],
old_rotation_eulers=[0.0, 0.0, 0.0],
old_rotation_orders=[0, 1, 2],
old_scales=[1.0, 1.0, 1.0],
usd_context_name='',
time_code=0.0)
omni.kit.commands.execute('CreateMeshPrimWithDefaultXform',
prim_type='Cube',
prim_path='/World/Xform/Cube',
select_new_prim=True,
prepend_default_prim=False)
omni.kit.commands.execute('TransformMultiPrimsSRTCpp',
count=1,
paths=['/World/Xform/Cube'],
new_translations=[4, 0, 0],
new_rotation_eulers=[100, 0 ,0],
new_rotation_orders=[0, 1, 2],
new_scales=[2, 2, 2],
old_translations=[0.0, 0.0, 0.0],
old_rotation_eulers=[0.0, 0.0, 0.0],
old_rotation_orders=[0, 1, 2],
old_scales=[1.0, 1.0, 1.0],
usd_context_name='',
time_code=0.0)
stage = omni.usd.get_context().get_stage()
cube_prim = stage.GetPrimAtPath("/World/Xform/Cube")
transform = get_world_transform_xform(cube_prim)