Isaac Sim Version
4.5.0
Operating System
Ubuntu 22.04
GPU Information
- Model: RTX A5000
- Driver Version: 550.163.01
Topic Description
Detailed Description
I was trying to use the edit the omni graph attributes of the conveyor (generated using the conveyor belt utility), where I was hit with OmniGraphError: Failed trying to look up attribute
For reference, this is my code:
from isaacsim import SimulationApp
simulation_app = SimulationApp({"headless": False})
import omni.usd
from pxr import Usd
import omni.graph.core as og
WORLD_USD = "/home/user/isaacsim/scripts/Conveyor_trials/trial_1.usd" # your world file
ATTR_NAME = "inputs:velocity"
NEW_VALUE = 0.75
CONVEYOR_GRAPHS = [# prim paths of the 3 ConveyorBeltGraph nodes
"/World/ConveyorTrack",
"/World/ConveyorTrack_01",
"/World/ConveyorTrack_02",
]
def open_stage(path: str) -> Usd.Stage:
ctx = omni.usd.get_context()
ctx.open_stage(path)
stage = ctx.get_stage()
if stage is None:
raise RuntimeError(f"Failed to open stage: {path}")
return stage
def set_attr(stage: Usd.Stage, prim_path: str, attr_name: str, value):
prim = stage.GetPrimAtPath(prim_path)
if not prim.IsValid():
print(f"[WARN] Missing prim: {prim_path}")
return False
attr = prim.GetAttribute(attr_name)
if not attr.IsValid():
print(f"[WARN] Missing attr '{attr_name}' on {prim_path}")
return False
def main():
stage = open_stage(WORLD_USD)
for p in CONVEYOR_GRAPHS:
attrib_name = f"{p}/ConveyorBeltGraph/ConveyorNode.inputs:velocity"
og.Controller.attribute(attrib_name).set(NEW_VALUE)
for _ in range(120):
simulation_app.update()
simulation_app.close()
if __name__ == "__main__":
main()
What am I doing wrong?
Error Messages
2025-10-13 07:30:19 [9,855ms] [Error] [omni.kit.app._impl] [py stderr]: Traceback (most recent call last):
2025-10-13 07:30:19 [9,855ms] [Error] [omni.kit.app._impl] [py stderr]: File "/home/user/isaacsim/extscache/omni.graph-1.140.2+d02c707b.lx64.r.cp310/omni/graph/core/_impl/object_lookup.py", line 383, in __attribute_from_info
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: specified_node = cls.node(node_name, graph)
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: File "/home/user/isaacsim/extscache/omni.graph-1.140.2+d02c707b.lx64.r.cp310/omni/graph/core/_impl/object_lookup.py", line 221, in node
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: return __node_from_info(node_id)
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: File "/home/user/isaacsim/extscache/omni.graph-1.140.2+d02c707b.lx64.r.cp310/omni/graph/core/_impl/object_lookup.py", line 214, in __node_from_info
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: raise og.OmniGraphValueError(f"Could not find OmniGraph node from node description '{node}' - {error}")
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: omni.graph.core._impl.errors.OmniGraphValueError: OmniGraphError: Could not find OmniGraph node from node description '/World/ConveyorTrack/ConveyorBeltGraph/ConveyorNode' - Node path '/World/ConveyorTrack/ConveyorBeltGraph/ConveyorNode' was not an OmniGraph node
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]:
The above exception was the direct cause of the following exception:
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: Traceback (most recent call last):
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: File "/home/user/isaacsim/scripts/Conveyor_trials/trial_1.py", line 52, in <module>
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: main()
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: File "/home/user/isaacsim/scripts/Conveyor_trials/trial_1.py", line 45, in main
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: og.Controller.attribute(attrib_name).set(NEW_VALUE)
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: File "/home/user/isaacsim/extscache/omni.graph-1.140.2+d02c707b.lx64.r.cp310/omni/graph/core/_impl/object_lookup.py", line 424, in attribute
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: return __attribute_from_info(attribute_id)
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: File "/home/user/isaacsim/extscache/omni.graph-1.140.2+d02c707b.lx64.r.cp310/omni/graph/core/_impl/object_lookup.py", line 415, in __attribute_from_info
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: raise og.OmniGraphError(
2025-10-13 07:30:19 [9,856ms] [Error] [omni.kit.app._impl] [py stderr]: omni.graph.core._impl.errors.OmniGraphError: OmniGraphError: Failed trying to look up attribute with (/World/ConveyorTrack/ConveyorBeltGraph/ConveyorNode.inputs:velocity, node=None, graph=None)
