Collision detection of a manipulator

Omniverse Isaac Sim
1

Hello.

I am trying to implement a function to detect collisions of my manipulator, below (Doosan M1013).

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The manipulator consists of several mesh parts, and the collision should be detected when the each part are overlapped (self collision detection).

I referenced these links, but they are quite difficult to customize on my python script.

https://docs.omniverse.nvidia.com/app_isaacsim/app_isaacsim/reference_python_snippets.html?#do-overlap-test

Would you let me know how I can implement the collision detection functions in my python script.

I attached the python file and M1013 usd file.

# Copyright (c) 2021, NVIDIA CORPORATION.  All rights reserved.
#
# NVIDIA CORPORATION and its licensors retain all intellectual property
# and proprietary rights in and to this software, related documentation
# and any modifications thereto.  Any use, reproduction, disclosure or
# distribution of this software and related documentation without an express
# license agreement from NVIDIA CORPORATION is strictly prohibited.

import carb
import omni.kit.commands
import omni.ext
import omni.appwindow
import weakref
import omni.kit.settings
import gc
import asyncio

from omni.kit.menu.utils import add_menu_items, remove_menu_items, MenuItemDescription

from pxr import Gf

from omni.isaac.core import PhysicsContext
from omni.isaac.core.utils.nucleus import find_nucleus_server
from omni.isaac.core.utils.prims import create_prim


############################
#### ContactRepoertDemo ####
############################
from omni.physx.scripts.physicsUtils import *
from pxr import Usd, UsdLux, UsdGeom, UsdShade, Sdf, Gf, Tf, Vt, UsdPhysics, PhysxSchema
from omni.physx import get_physx_interface
from omni.physx.bindings._physx import SimulationEvent
from random import seed
from random import random
import omni.physxdemos as demo

MENU_NAME = "M1013 Collision detection"


class Extension(omni.ext.IExt):
    def on_startup(self):
        """Initialize extension and UI elements"""
        self._timeline = omni.timeline.get_timeline_interface()
        self._viewport = omni.kit.viewport.get_default_viewport_window()
        self._usd_context = omni.usd.get_context()
        self._stage = self._usd_context.get_stage()
        self._window = None

        menu_items = [MenuItemDescription(name=MENU_NAME, onclick_fn=lambda a=weakref.proxy(self): a._menu_callback())]
        self._menu_items = [MenuItemDescription(name="Demo", sub_menu=menu_items)]
        add_menu_items(self._menu_items, "Isaac Examples")

        events = get_physx_interface().get_simulation_event_stream()
        self._simulation_event_sub = events.create_subscription_to_pop(self._on_simulation_event)


    def _menu_callback(self):
        self._on_environment_setup()
        pass

    async def _create_moveit_sample(self):
        await omni.usd.get_context().new_stage_async()
        await omni.kit.app.get_app().next_update_async()
        
        self._viewport.set_camera_position("/OmniverseKit_Persp", 200, 500, 200, True)
        self._viewport.set_camera_target("/OmniverseKit_Persp", 0, 0, 50, True)
        self._stage = self._usd_context.get_stage()

        await omni.kit.app.get_app().next_update_async()
        create_prim(
            prim_path="/background", usd_path=self._nucleus_path + "/Isaac/Environments/Grid/gridroom_black.usd"
        )
        create_prim(
            prim_path="/M1013",
            usd_path=self._nucleus_path + "/Projects/K-CLOUD/DigitalTwin_Workshop/Robot/m1013_d415_vgc10_ver2.usd"
        )
        await omni.kit.app.get_app().next_update_async()

        ###########################
        #### ContactReportDemo ####
        ###########################      
        RobotPrim = self._stage.GetPrimAtPath("/M1013")
        print("RobotPrim = ", RobotPrim)
        contactReportAPI = PhysxSchema.PhysxContactReportAPI.Apply(RobotPrim)
        contactReportAPI.CreateThresholdAttr().Set(1)
        ########################### 

        PhysicsContext(physics_dt=1.0 / 60.0)
        
        
        await omni.kit.app.get_app().next_update_async()
        # num_hit = self.check_overlap_box()
        # print("Numhit = ",num_hit )        
  
    
        await omni.kit.app.get_app().next_update_async()

        self._timeline.play()

    def _on_environment_setup(self):

        result, nucleus_server = find_nucleus_server()
        if result is False:
            carb.log_error("Could not find nucleus server with /Isaac folder")
            return
        self._nucleus_path = nucleus_server

        asyncio.ensure_future(self._create_moveit_sample())

    def on_shutdown(self):  
        """Cleanup objects on extension shutdown"""
        self._timeline.stop()
        remove_menu_items(self._menu_items, "Isaac Examples")
        self._window = None
        gc.collect()
    
    def _on_simulation_event(self, event):
        if event.type == int(SimulationEvent.CONTACT_FOUND):
            print("Contact found:!!!!!!!")

m1013_d415_vgc10_ver2.usd (49.0 MB)

Thank you !

3

@swimpark This is currently not easy to do at the Python level. This is something we are aiming to support in an upcoming release.

4

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