The simulation suddenly closed without an error


I ran my code on the latest version of OIGE & skrl. However, the code suddenly shut down just after the world was created.

I cannot get any reason because there are any error messages. When I tried to find the reason, I found that the self._app is None where self._app.update() was iterated second at the end of the below code (from ./exts/omni.isaac.core/omni/isaac/core/simulation_context/

    def step(self, render: bool = True) -> None:
        """Steps the physics simulation while rendering or without.

            render (bool, optional): Set to False to only do a physics simulation without rendering. Note:
                                     app UI will be frozen (since its not rendering) in this case.
                                     Defaults to True.

            Exception: [description]
        if self.stage is None:
            raise Exception("There is no stage currently opened, init_stage needed before calling this func")
        if render:
            # physics dt is zero, no need to step physics, just render
            if self.get_physics_dt() == 0:
            # rendering dt is zero, but physics is not, call step and then render
            elif self.get_rendering_dt() == 0 and self.get_physics_dt() != 0:
                if self.is_playing():
                    if self._physics_sim_view is not None:
                    # if self._physics_sim_view is not None:
                    #     self._physics_sim_view.clear_forces()
                if self._physics_sim_view is not None:
                # if self._physics_sim_view is not None:
                #     self._physics_sim_view.clear_forces()

Here is my code.
moving_target.7z (11.3 MB)


Hi @psh9002

The issue is similar to the one we already discussed here: Cannot apply gravity to the objects and add DynamicCylinder · Toni-SM/skrl · Discussion #69 · GitHub

You are using a Cylinder shape for the tool and this crashes the simulation.
Change it to a mesh and it will work.

Btw, check the next link (OIGE massless-links) to solve the warnings:

[Warning] [omni.physx.plugin] The rigid body at /World/envs/env_0/robot/world has a possibly invalid inertia tensor of {1.0, 1.0, 1.0} and a negative mass, small sphere approximated inertia was used. Either specify correct values in the mass properties, or add collider(s) to any shape(s) that you wish to automatically compute mass properties for. If you do not want the objects to collide, add colliders regardless then disable the ‘enable collision’ property.

1 Like


The code works well with your solution.

I’ve always been appreciative of you!

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