Getting Contact Map between Two Objects

Omniverse Isaac Sim
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1

Isaac Sim Version

4.2.0
4.1.0
4.0.0
2023.1.1
2023.1.0-hotfix.1
Other (please specify):

Isaac Lab Version (if applicable)

1.2
1.1
1.0
Other (please specify):

Operating System

Ubuntu 22.04
Ubuntu 20.04
Windows 11
Windows 10
Other (please specify):

GPU Information

  • Model: RTX 4090
  • Driver Version: 535.183.01

Topic Description

I am working on in hand manipulation and want to extract contact map between the hand and the object, I looked into the contact sensor but I don’t believe it gives a map in any way. The contact map can honestly be in any format, a discrete representation of evenly spaced points, or even a convex hull of some sort that contains the regions between hand and object that are in contact. Are there any predefined methods to do this?

Screenshots or Videos

Current Setup:

cubehand
cubehand925×785 32.4 KB

2

Associated code:

import argparse
from omni.isaac.lab.app import AppLauncher
parser = argparse.ArgumentParser(description="Contact Prior Data Collection")
AppLauncher.add_app_launcher_args(parser)
args_cli = parser.parse_args()
app_launcher = AppLauncher(args_cli)
simulation_app = app_launcher.app


import os
import torch
import omni.isaac.core.utils.prims as prim_utils
import omni.isaac.lab.sim as sim_utils
from omni.isaac.lab.actuators import ImplicitActuatorCfg
from omni.isaac.lab.assets import ArticulationCfg, AssetBaseCfg
from omni.isaac.lab.scene import InteractiveScene, InteractiveSceneCfg
from omni.isaac.lab.sim import SimulationCfg, SimulationContext
from omni.isaac.lab.sensors import CameraCfg, ContactSensorCfg, patterns
from omni.isaac.core.utils.rotations import euler_angles_to_quat
from omni.isaac.lab.utils import configclass

CURRENT_DIR = os.path.dirname(os.path.abspath(__file__))

LEAP_HAND_CFG = ArticulationCfg(
    spawn=sim_utils.UsdFileCfg(
        activate_contact_sensors = True,
        usd_path=f"{CURRENT_DIR}/assets/right_hand.usd",
        rigid_props=sim_utils.RigidBodyPropertiesCfg(
            rigid_body_enabled=True,
            max_linear_velocity=1000.0,
            max_angular_velocity=1000.0,
            max_depenetration_velocity=100.0,
            enable_gyroscopic_forces=True,
        ),
        articulation_props=sim_utils.ArticulationRootPropertiesCfg(
            enabled_self_collisions=False,
            solver_position_iteration_count=4,
            solver_velocity_iteration_count=0,
            sleep_threshold=0.005,
            stabilization_threshold=0.001,
        ),
    ),
    init_state=ArticulationCfg.InitialStateCfg(
        pos=(0.0, 0.0, 1.0),
        rot=(0.0, 0.0, 1.0, 0.0)
    ),
    actuators={
    "all_joints": ImplicitActuatorCfg(
        joint_names_expr=[".*"],
        effort_limit=0.91,
        velocity_limit=8.48,
        stiffness=None,
        damping=None,
    ),
},
)

qx, qy, qz, qw = euler_angles_to_quat((0.0, 0.0, torch.pi/2))
@configclass
class LeapHandSceneCfg(InteractiveSceneCfg):
    ground = AssetBaseCfg(prim_path="/World/defaultGroundPlane", spawn=sim_utils.GroundPlaneCfg(color=(0.5, 0.5, 0.5)))
    
    dome_light = AssetBaseCfg(
        prim_path="/World/Light", spawn=sim_utils.DomeLightCfg(intensity=3000.0, color=(0.75, 0.75, 0.75))
    )
    leap_hand: ArticulationCfg = LEAP_HAND_CFG.replace(prim_path="/World/Robot")

    cube = AssetBaseCfg(
        prim_path="/World/Cube",
        init_state=AssetBaseCfg.InitialStateCfg(
            pos=(0.0, 0.0, 1.25),
            rot=(0.0, 0.0, 0.0, 1.0)
        ),
        spawn=sim_utils.MeshCuboidCfg(
            activate_contact_sensors = True,
            size=(0.075, 0.075, 0.075),
            rigid_props=sim_utils.RigidBodyPropertiesCfg(),
            mass_props=sim_utils.MassPropertiesCfg(mass=0.05),
            collision_props=sim_utils.CollisionPropertiesCfg(),
            visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(0.0, 0.0, 1.0))
        )
    )
    camera = CameraCfg(
        prim_path="/World/Robot/palm_lower/front_cam",
        update_period=0.1,
        height=480,
        width=640,
        data_types=["rgb", "distance_to_image_plane"],
        spawn=sim_utils.PinholeCameraCfg(
            focal_length=24.0, focus_distance=400.0, horizontal_aperture=20.955, clipping_range=(0.1, 1.0e5)
        ),
        offset=CameraCfg.OffsetCfg(pos=(0.0, 0.0, -0.65),  rot=(qx.item(), qy.item(), qz.item(), qw.item()), convention="ros"),
    )

    contact_forces = ContactSensorCfg(
        prim_path="/World/Cube", update_period=0.0, history_length=6, debug_vis=True,
    )

def main():
    sim_cfg = SimulationCfg(device=args_cli.device)
    sim = SimulationContext(sim_cfg)
    sim.set_camera_view([0.25, -0.25, 1.40], [0.0, 0.0, torch.pi * 0.325])

    scene_cfg = LeapHandSceneCfg(num_envs=1, env_spacing=2.0)
    scene = InteractiveScene(scene_cfg)

    sim.reset()
    print("[INFO]: Setup complete...")

    robot = scene["leap_hand"]
    sim_dt = sim.get_physics_dt()

    while simulation_app.is_running():
        target_position = torch.tensor([
            torch.pi * 0.0,  #1
            torch.pi * 0.0,  #0
            torch.pi * 0.0,  #2
            torch.pi * 0.0,  #3
            torch.pi * 0.0,  #9
            torch.pi * 0.0,  #8
            torch.pi * 0.0,  #10
            torch.pi * 0.0,  #11
            torch.pi * 0.0,  #13
            torch.pi * 0.0,  #12
            torch.pi * 0.0,  #14
            torch.pi * 0.0,  #15
            torch.pi * 0.0,  #4
            torch.pi * 0.0,  #5
            torch.pi * 0.0,  #6
            torch.pi * 0.0,  #7
        ], device=robot.data.joint_pos.device)

        joint_pos = target_position * torch.ones_like(robot.data.joint_pos)
        robot.set_joint_position_target(joint_pos)
        scene.write_data_to_sim()

        sim.step()
        scene.update(sim_dt)

if __name__ == "__main__":
    main()
    simulation_app.close()
4

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