Changing the location of spawn -- with forklift_prim: AttributeError: __enter__ Simulation App Shutting Down

Omniverse Synthetic Data Generation (SDG)
1

I am initially spawning a forklift after main() and then spawn other objects every frame around it.

So, now, I am interested in changing the location of spawn forklift every frame too.

Could you guide me how to fix this?

The code is:

def main():
    # Open the environment in a new stage
    print(f"Loading Stage {ENV_URL}")
    open_stage(prefix_with_isaac_asset_server(ENV_URL))

    # Create a custom scope for newly added prims
    stage = get_current_stage()
    
    floor_prims = [x.GetPath() for x in stage.Traverse() if "SM_floor" in x.GetName() and prims_utils.get_prim_type_name(x.GetPath()) == "Xform"]
    
    bb_cache = bounds_utils.create_bbox_cache()
    combined_range_arr = bounds_utils.compute_combined_aabb(bb_cache, prim_paths=floor_prims)

    margin = 0.5
    min_x, min_y, min_z, max_x, max_y, max_z = combined_range_arr
    position = (np.random.uniform(min_x + margin, max_x - margin),  # x
            np.random.uniform(min_y + margin, max_y - margin),  # y
            0)                                                  # z

    scope = UsdGeom.Scope.Define(stage, SCOPE_NAME) # mona score is not used anywhere!!!

    
    # Spawn a custom forklift at a random pose
    forklift_prim = prims.create_prim(
        prim_path=f"{SCOPE_NAME}/Custom_Forklift",
        position = position,
        orientation=euler_angles_to_quat([0, 0, random.uniform(0, math.pi)]), random.uniform(0, math.pi)]),
        usd_path=CUSTOM_FORKLIFT_URL,
        semantic_label="Forklift",
    )

    with rep.trigger.on_frame(num_frames=CONFIG["num_frames"]):
        
        position = (np.random.uniform(min_x + margin, max_x - margin),  # x
        np.random.uniform(min_y + margin, max_y - margin),  # y
        0)                                                  # z


        rep.randomizer.scatter_boxes()
        rep.randomizer.randomize_lights()
        rep.randomizer.randomize_color()
        
        with forklift_prim:
            rep.modify.pose(
                position=position,
                rotation=rep.distribution.uniform((-90,-180, 0), (-90, 180, 0)),
            )

The error is:


2023-02-21 18:16:26 [24,074ms] [Warning] [omni.physx.plugin] PhysicsUSD: Parse collision - triangle mesh collision (approximation None/MeshSimplifixation) without SDF cannot be a part of a dynamic body, falling back to convexHull approximation: /MyScope/SimulatedCardbox_44/SM_CardBoxD_04. To enable SDF collisions, sdfResolution should be > 0.
2023-02-21 18:16:26 [24,074ms] [Warning] [omni.physx.plugin] PhysicsUSD: Parse collision - triangle mesh collision (approximation None/MeshSimplifixation) without SDF cannot be a part of a dynamic body, falling back to convexHull approximation: /MyScope/SimulatedCardbox_45/SM_CardBoxD_04. To enable SDF collisions, sdfResolution should be > 0.
2023-02-21 18:16:26 [24,074ms] [Warning] [omni.physx.plugin] PhysicsUSD: Parse collision - triangle mesh collision (approximation None/MeshSimplifixation) without SDF cannot be a part of a dynamic body, falling back to convexHull approximation: /MyScope/SimulatedCardbox_46/SM_CardBoxD_04. To enable SDF collisions, sdfResolution should be > 0.
2023-02-21 18:16:26 [24,074ms] [Warning] [omni.physx.plugin] PhysicsUSD: Parse collision - triangle mesh collision (approximation None/MeshSimplifixation) without SDF cannot be a part of a dynamic body, falling back to convexHull approximation: /MyScope/SimulatedCardbox_47/SM_CardBoxD_04. To enable SDF collisions, sdfResolution should be > 0.
2023-02-21 18:16:26 [24,074ms] [Warning] [omni.physx.plugin] PhysicsUSD: Parse collision - triangle mesh collision (approximation None/MeshSimplifixation) without SDF cannot be a part of a dynamic body, falling back to convexHull approximation: /MyScope/SimulatedCardbox_48/SM_CardBoxD_04. To enable SDF collisions, sdfResolution should be > 0.
2023-02-21 18:16:26 [24,074ms] [Warning] [omni.physx.plugin] PhysicsUSD: Parse collision - triangle mesh collision (approximation None/MeshSimplifixation) without SDF cannot be a part of a dynamic body, falling back to convexHull approximation: /MyScope/SimulatedCardbox_49/SM_CardBoxD_04. To enable SDF collisions, sdfResolution should be > 0.
Simulation stopped after 217 steps
2023-02-21 18:16:29 [26,988ms] [Warning] [carb.flatcache.plugin] UsdRelationship /Replicator/SDGPipeline/OgnGroup_08.inputs:prims has multiple targets, which is not supported

/buildAgent/work/f25a4639a4b1bdc1/source/foundation/FdFoundation.cpp (162) : invalid operation : Foundation object exists already. Only one instance per process can be created.

inspect.signature(rep.randomizer.scatter_2d):  (surface_prims: Union[omni.replicator.core.scripts.utils.utils.ReplicatorItem, List[str]], seed: int = None, offset: int = 0, check_for_collisions: bool = False, input_prims: Union[omni.replicator.core.scripts.utils.utils.ReplicatorItem, List[str]] = None)
2023-02-21 18:16:37 [35,141ms] [Error] [__main__] Exception: __enter__
Traceback (most recent call last):
  File "/home/mona/SDG/omniverse-sdg/offline_generation.py", line 752, in <module>
    main()
  File "/home/mona/SDG/omniverse-sdg/offline_generation.py", line 599, in main
    with forklift_prim:
AttributeError: __enter__
[35.521s] Simulation App Shutting Down
1 Like
2

Actually, I wrote this function and I am not getting error. The change of position of forklift is minimal and hard to judge

    
    def randomize_forklift_position(position):
        forklift = rep.get.prims(semantics=[('Custom_Forklift')])
        with forklift:
            rep.modify.pose(
                position=position,
                rotation=rep.distribution.uniform((-90,-180, 0), (-90, 180, 0)),
            )
            
        return forklift.node
    rep.randomizer.register(randomize_forklift_position)

and now I call it like this:

    with rep.trigger.on_frame(num_frames=CONFIG["num_frames"]):
        
        position = (np.random.uniform(min_x + margin, max_x - margin),  # x
        np.random.uniform(min_y + margin, max_y - margin),  # y
        0)                                                  # z

        

        rep.randomizer.scatter_boxes()
        rep.randomizer.scatter_pallets()
        rep.randomizer.randomize_lights()
        rep.randomizer.randomize_color()
        rep.randomizer.randomize_forklift_position(position)

Please let me know about your thoughts.

Somehow the rotation of forklift is not changing at all.

1 Like
3

Can you check if your rep.get.prims returns the requested prims?

For such questions it is always best to provide a script that we can reproduce. Best case in a very simple scenario containing only the function producing the issue. This way we can quickly test and check for a solution.