Running GUI (visualisation) on the desktop

[chenyu32]

Hello,

I am trying to run a Brax environment locally on my Ubuntu machine, I saw the examples in the Google colab website, but they use HTML for visualisation. I would like to write a Python script that shows the environment on the desktop. Is there a desktop GUI alternative?

Thank you for your time.

[btaba]

Hi chenyu32@, in your python script you can write to a file such as viz.html and open the html file in the browser to see a visualization. Does that work for you?

with open('somepath/viz.html', 'w') as f:
  f.write(html.render(sys, qps))

[chenyu32]

Hi, I have reviewed the code you suggested and tried to make it compatible with my model, but when I run the code, a blank window pops up which is supposed to be the html visulisation. May I ask what did I miss?

Thank you for your time.

[btaba]

Hi @chenyu32, what are you running exactly?

[chenyu32]

I would like to first use the 'ant' example regarding brax on githab to test brax on my desktop. The complete code is as follows.

# Copyright 2022 The Brax Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Trains a ur5e robot arm to move its end effector to a sequence of targets.

The 6 joints have been placed faithfully to the actual joint locations of the
ur5e robot arm model.  Because brax does not yet support meshes, the capsule
locations for collider boundaries are only approximate.

See https://www.universal-robots.com/products/ur5-robot/ for more details.
"""

from typing import Tuple

import brax
from brax import jumpy as jp
from brax import math
from brax.envs import env
from brax.io import html
import sys
from brax import envs

# Copyright 2022 The Brax Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Trains an ant to run in the +x direction."""


from brax import jumpy as jp


class Ant(env.Env):


  """
  ### Description
  This environment is based on the environment introduced by Schulman, Moritz,
  Levine, Jordan and Abbeel in
  ["High-Dimensional Continuous Control Using Generalized Advantage Estimation"](https://arxiv.org/abs/1506.02438).
  The ant is a 3D robot consisting of one torso (free rotational body) with four
  legs attached to it with each leg having two links.
  The goal is to coordinate the four legs to move in the forward (right)
  direction by applying torques on the eight hinges connecting the two links of
  each leg and the torso (nine parts and eight hinges).
  ### Action Space
  The agent take a 8-element vector for actions.
  The action space is a continuous `(action, action, action, action, action,
  action, action, action)` all in `[-1, 1]`, where `action` represents the
  numerical torques applied at the hinge joints.
  | Num | Action                                                             | Control Min | Control Max | Name (in corresponding config)   | Joint | Unit         |
  |-----|--------------------------------------------------------------------|-------------|-------------|----------------------------------|-------|--------------|
  | 0   | Torque applied on the rotor between the torso and front left hip   | -1          | 1           | hip_1 (front_left_leg)           | hinge | torque (N m) |
  | 1   | Torque applied on the rotor between the front left two links       | -1          | 1           | ankle_1 (front_left_leg)         | hinge | torque (N m) |
  | 2   | Torque applied on the rotor between the torso and front right hip  | -1          | 1           | hip_2 (front_right_leg)          | hinge | torque (N m) |
  | 3   | Torque applied on the rotor between the front right two links      | -1          | 1           | ankle_2 (front_right_leg)        | hinge | torque (N m) |
  | 4   | Torque applied on the rotor between the torso and back left hip    | -1          | 1           | hip_3 (back_leg)                 | hinge | torque (N m) |
  | 5   | Torque applied on the rotor between the back left two links        | -1          | 1           | ankle_3 (back_leg)               | hinge | torque (N m) |
  | 6   | Torque applied on the rotor between the torso and back right hip   | -1          | 1           | hip_4 (right_back_leg)           | hinge | torque (N m) |
  | 7   | Torque applied on the rotor between the back right two links       | -1          | 1           | ankle_4 (right_back_leg)         | hinge | torque (N m) |
  ### Observation Space
  The state space consists of positional values of different body parts of the
  ant, followed by the velocities of those individual parts (their derivatives)
  with all the positions ordered before all the velocities.
  The observation is a `ndarray` with shape `(27,)` where the elements correspond to the following:
  | Num | Observation                                                  | Min  | Max | Name (in corresponding config)   | Joint | Unit                     |
  |-----|--------------------------------------------------------------|------|-----|----------------------------------|-------|--------------------------|
  | 0   | z-coordinate of the torso (centre)                           | -Inf | Inf | torso                            | free  | position (m)             |
  | 1   | w-orientation of the torso (centre)                          | -Inf | Inf | torso                            | free  | angle (rad)              |
  | 2   | x-orientation of the torso (centre)                          | -Inf | Inf | torso                            | free  | angle (rad)              |
  | 3   | y-orientation of the torso (centre)                          | -Inf | Inf | torso                            | free  | angle (rad)              |
  | 4   | z-orientation of the torso (centre)                          | -Inf | Inf | torso                            | free  | angle (rad)              |
  | 5   | angle between torso and first link on front left             | -Inf | Inf | hip_1 (front_left_leg)           | hinge | angle (rad)              |
  | 6   | angle between the two links on the front left                | -Inf | Inf | ankle_1 (front_left_leg)         | hinge | angle (rad)              |
  | 7   | angle between torso and first link on front right            | -Inf | Inf | hip_2 (front_right_leg)          | hinge | angle (rad)              |
  | 8   | angle between the two links on the front right               | -Inf | Inf | ankle_2 (front_right_leg)        | hinge | angle (rad)              |
  | 9   | angle between torso and first link on back left              | -Inf | Inf | hip_3 (back_leg)                 | hinge | angle (rad)              |
  | 10  | angle between the two links on the back left                 | -Inf | Inf | ankle_3 (back_leg)               | hinge | angle (rad)              |
  | 11  | angle between torso and first link on back right             | -Inf | Inf | hip_4 (right_back_leg)           | hinge | angle (rad)              |
  | 12  | angle between the two links on the back right                | -Inf | Inf | ankle_4 (right_back_leg)         | hinge | angle (rad)              |
  | 13  | x-coordinate velocity of the torso                           | -Inf | Inf | torso                            | free  | velocity (m/s)           |
  | 14  | y-coordinate velocity of the torso                           | -Inf | Inf | torso                            | free  | velocity (m/s)           |
  | 15  | z-coordinate velocity of the torso                           | -Inf | Inf | torso                            | free  | velocity (m/s)           |
  | 16  | x-coordinate angular velocity of the torso                   | -Inf | Inf | torso                            | free  | angular velocity (rad/s) |
  | 17  | y-coordinate angular velocity of the torso                   | -Inf | Inf | torso                            | free  | angular velocity (rad/s) |
  | 18  | z-coordinate angular velocity of the torso                   | -Inf | Inf | torso                            | free  | angular velocity (rad/s) |
  | 19  | angular velocity of angle between torso and front left link  | -Inf | Inf | hip_1 (front_left_leg)           | hinge | angle (rad)              |
  | 20  | angular velocity of the angle between front left links       | -Inf | Inf | ankle_1 (front_left_leg)         | hinge | angle (rad)              |
  | 21  | angular velocity of angle between torso and front right link | -Inf | Inf | hip_2 (front_right_leg)          | hinge | angle (rad)              |
  | 22  | angular velocity of the angle between front right links      | -Inf | Inf | ankle_2 (front_right_leg)        | hinge | angle (rad)              |
  | 23  | angular velocity of angle between torso and back left link   | -Inf | Inf | hip_3 (back_leg)                 | hinge | angle (rad)              |
  | 24  | angular velocity of the angle between back left links        | -Inf | Inf | ankle_3 (back_leg)               | hinge | angle (rad)              |
  | 25  | angular velocity of angle between torso and back right link  | -Inf | Inf | hip_4 (right_back_leg)           | hinge | angle (rad)              |
  | 26  | angular velocity of the angle between back right links       | -Inf | Inf | ankle_4 (right_back_leg)         | hinge | angle (rad)              |
  The (x,y,z) coordinates are translational DOFs while the orientations are
  rotational DOFs expressed as quaternions.
  If use_contact_forces=True, contact forces are added to the observation:
  external forces and torques applied to the center of mass of each of the
  links. 60 extra dimensions: the torso link, 8 leg links, and the ground link
  (10 total), with 6 external forces each (force x, y, z, torque x, y, z).
  ### Rewards
  The reward consists of three parts:
  - *reward_survive*: Every timestep that the ant is alive, it gets a reward of
    1.
  - *reward_forward*: A reward of moving forward which is measured as
    *(x-coordinate before action - x-coordinate after action)/dt*. *dt* is the
    time between actions - the default *dt = 0.05*. This reward would be
    positive if the ant moves forward (right) desired.
  - *reward_ctrl*: A negative reward for penalising the ant if it takes actions
    that are too large. It is measured as *coefficient **x**
    sum(action<sup>2</sup>)* where *coefficient* is a parameter set for the
    control and has a default value of 0.5.
  - *contact_cost*: A negative reward for penalising the ant if the external
    contact force is too large. It is calculated *0.5 * 0.001 *
    sum(clip(external contact force to [-1,1])<sup>2</sup>)*.
  ### Starting State
  All observations start in state (0.0, 0.0,  0.75, 1.0, 0.0  ... 0.0) with a
  uniform noise in the range of [-0.1, 0.1] added to the positional values and
  standard normal noise with 0 mean and 0.1 standard deviation added to the
  velocity values for stochasticity.
  Note that the initial z coordinate is intentionally selected to be slightly
  high, thereby indicating a standing up ant. The initial orientation is
  designed to make it face forward as well.
  ### Episode Termination
  The episode terminates when any of the following happens:
  1. The episode duration reaches a 1000 timesteps
  2. The y-orientation (index 2) in the state is **not** in the range
     `[0.2, 1.0]`
  ### Arguments
  No additional arguments are currently supported (in v2 and lower), but
  modifications can be made to the XML file in the assets folder (or by changing
  the path to a modified XML file in another folder).

env = gym.make('Ant-v2')

v3, v4, and v5 take gym.make kwargs such as ctrl_cost_weight,
reset_noise_scale etc.

env = gym.make('Ant-v5', ctrl_cost_weight=0.1, ....)

### Version History
* v5: ported to Brax.
* v4: all mujoco environments now use the mujoco bindings in mujoco>=2.1.3
* v3: support for gym.make kwargs such as xml_file, ctrl_cost_weight,
      reset_noise_scale etc. rgb rendering comes from tracking camera (so
      agent does not run away from screen)
* v2: All continuous control environments now use mujoco_py >= 1.50
* v1: max_time_steps raised to 1000 for robot based tasks. Added
      reward_threshold to environments.
* v0: Initial versions release (1.0.0)
"""


def __init__(self,
             ctrl_cost_weight=0.5,
             use_contact_forces=False,
             contact_cost_weight=5e-4,
             healthy_reward=1.0,
             terminate_when_unhealthy=True,
             healthy_z_range=(0.2, 1.0),
             reset_noise_scale=0.1,
             exclude_current_positions_from_observation=True,
             legacy_spring=False,
             **kwargs):
  config = _SYSTEM_CONFIG_SPRING if legacy_spring else _SYSTEM_CONFIG
  super().__init__(config=config, **kwargs)

  self._ctrl_cost_weight = ctrl_cost_weight
  self._use_contact_forces = use_contact_forces
  self._contact_cost_weight = contact_cost_weight
  self._healthy_reward = healthy_reward
  self._terminate_when_unhealthy = terminate_when_unhealthy
  self._healthy_z_range = healthy_z_range
  self._reset_noise_scale = reset_noise_scale
  self._exclude_current_positions_from_observation = (
      exclude_current_positions_from_observation
  )

def reset(self, rng: jp.ndarray) -> env.State:
  """Resets the environment to an initial state."""
  rng, rng1, rng2 = jp.random_split(rng, 3)

  qpos = self.sys.default_angle() + self._noise(rng1)
  qvel = self._noise(rng2)

  qp = self.sys.default_qp(joint_angle=qpos, joint_velocity=qvel)
  obs = self._get_obs(qp, self.sys.info(qp))
  reward, done, zero = jp.zeros(3)
  metrics = {
      'reward_forward': zero,
      'reward_survive': zero,
      'reward_ctrl': zero,
      'reward_contact': zero,
      'x_position': zero,
      'y_position': zero,
      'distance_from_origin': zero,
      'x_velocity': zero,
      'y_velocity': zero,
      'forward_reward': zero,
  }
  return env.State(qp, obs, reward, done, metrics)

def step(self, state: env.State, action: jp.ndarray) -> env.State:
  """Run one timestep of the environment's dynamics."""
  qp, info = self.sys.step(state.qp, action)

  velocity = (qp.pos[0] - state.qp.pos[0]) / self.sys.config.dt
  forward_reward = velocity[0]

  min_z, max_z = self._healthy_z_range
  is_healthy = jp.where(qp.pos[0, 2] < min_z, x=0.0, y=1.0)
  is_healthy = jp.where(qp.pos[0, 2] > max_z, x=0.0, y=is_healthy)
  if self._terminate_when_unhealthy:
    healthy_reward = self._healthy_reward
  else:
    healthy_reward = self._healthy_reward * is_healthy
  ctrl_cost = self._ctrl_cost_weight * jp.sum(jp.square(action))
  contact_cost = (self._contact_cost_weight *
                  jp.sum(jp.square(jp.clip(info.contact.vel, -1, 1))))
  obs = self._get_obs(qp, info)
  reward = forward_reward + healthy_reward - ctrl_cost - contact_cost
  done = 1.0 - is_healthy if self._terminate_when_unhealthy else 0.0
  state.metrics.update(
      reward_forward=forward_reward,
      reward_survive=healthy_reward,
      reward_ctrl=-ctrl_cost,
      reward_contact=-contact_cost,
      x_position=qp.pos[0, 0],
      y_position=qp.pos[0, 1],
      distance_from_origin=jp.norm(qp.pos[0]),
      x_velocity=velocity[0],
      y_velocity=velocity[1],
      forward_reward=forward_reward,
  )

  return state.replace(qp=qp, obs=obs, reward=reward, done=done)

def _get_obs(self, qp: brax.QP, info: brax.Info) -> jp.ndarray:
  """Observe ant body position and velocities."""
  joint_angle, joint_vel = self.sys.joints[0].angle_vel(qp)

  # qpos: position and orientation of the torso and the joint angles.
  if self._exclude_current_positions_from_observation:
    qpos = [qp.pos[0, 2:], qp.rot[0], joint_angle]
  else:
    qpos = [qp.pos[0], qp.rot[0], joint_angle]

  # qvel: velocity of the torso and the joint angle velocities.
  qvel = [qp.vel[0], qp.ang[0], joint_vel]

  # external contact forces:
  # delta velocity (3,), delta ang (3,) * 10 bodies in the system
  if self._use_contact_forces:
    cfrc = [
        jp.clip(info.contact.vel, -1, 1),
        jp.clip(info.contact.ang, -1, 1)
    ]
    # flatten bottom dimension
    cfrc = [jp.reshape(x, x.shape[:-2] + (-1,)) for x in cfrc]
  else:
    cfrc = []

  return jp.concatenate(qpos + qvel + cfrc)

def _noise(self, rng):
  low, hi = -self._reset_noise_scale, self._reset_noise_scale
  return jp.random_uniform(rng, (self.sys.num_joint_dof,), low, hi)

# TODO: name bodies in config according to mujoco xml

_SYSTEM_CONFIG = """
bodies {
  name: "$ Torso"
  colliders {
    capsule {
      radius: 0.25
      length: 0.5
      end: 1
    }
  }
  inertia { x: 1.0 y: 1.0 z: 1.0 }
  mass: 10
}
bodies {
  name: "Aux 1"
  colliders {
    rotation { x: 90 y: -45 }
    capsule {
      radius: 0.08
      length: 0.4428427219390869
    }
  }
  inertia { x: 1.0 y: 1.0 z: 1.0 }
  mass: 1
}
bodies {
  name: "$ Body 4"
  colliders {
    rotation { x: 90 y: -45 }
    capsule {
      radius: 0.08
      length: 0.7256854176521301
      end: -1
    }
  }
  inertia { x: 1.0 y: 1.0 z: 1.0 }
  mass: 1
}
bodies {
  name: "Aux 2"
  colliders {
    rotation { x: 90 y: 45 }
    capsule {
      radius: 0.08
      length: 0.4428427219390869
    }
  }
  inertia { x: 1.0 y: 1.0 z: 1.0 }
  mass: 1
}
bodies {
  name: "$ Body 7"
  colliders {
    rotation { x: 90 y: 45 }
    capsule {
      radius: 0.08
      length: 0.7256854176521301
      end: -1
    }
  }
  inertia { x: 1.0 y: 1.0 z: 1.0 }
  mass: 1
}
bodies {
  name: "Aux 3"
  colliders {
    rotation { x: -90 y: 45 }
    capsule {
      radius: 0.08
      length: 0.4428427219390869
    }
  }
  inertia { x: 1.0 y: 1.0 z: 1.0 }
  mass: 1
}
bodies {
  name: "$ Body 10"
  colliders {
    rotation { x: -90 y: 45 }
    capsule {
      radius: 0.08
      length: 0.7256854176521301
      end: -1
    }
  }
  inertia { x: 1.0 y: 1.0 z: 1.0 }
  mass: 1
}
bodies {
  name: "Aux 4"
  colliders {
    rotation { x: -90 y: -45 }
    capsule {
      radius: 0.08
      length: 0.4428427219390869
    }
  }
  inertia { x: 1.0 y: 1.0 z: 1.0 }
  mass: 1
}
bodies {
  name: "$ Body 13"
  colliders {
    rotation { x: -90 y: -45 }
    capsule {
      radius: 0.08
      length: 0.7256854176521301
      end: -1
    }
  }
  inertia { x: 1.0 y: 1.0 z: 1.0 }
  mass: 1
}
bodies {
  name: "Ground"
  colliders {
    plane {}
  }
  inertia { x: 1.0 y: 1.0 z: 1.0 }
  mass: 1
  frozen { all: true }
}
joints {
  name: "hip_1"
  parent_offset { x: 0.2 y: 0.2 }
  child_offset { x: -0.1 y: -0.1 }
  parent: "$ Torso"
  child: "Aux 1"
  angle_limit { min: -30.0 max: 30.0 }
  rotation { y: -90 }
  angular_damping: 20
}
joints {
  name: "ankle_1"
  parent_offset { x: 0.1 y: 0.1 }
  child_offset { x: -0.2 y: -0.2 }
  parent: "Aux 1"
  child: "$ Body 4"
  rotation: { z: 135 }
  angle_limit {
    min: 30.0
    max: 70.0
  }
  angular_damping: 20
}
joints {
  name: "hip_2"
  parent_offset { x: -0.2 y: 0.2 }
  child_offset { x: 0.1 y: -0.1 }
  parent: "$ Torso"
  child: "Aux 2"
  rotation { y: -90 }
  angle_limit { min: -30.0 max: 30.0 }
  angular_damping: 20
}
joints {
  name: "ankle_2"
  parent_offset { x: -0.1 y: 0.1 }
  child_offset { x: 0.2 y: -0.2 }
  parent: "Aux 2"
  child: "$ Body 7"
  rotation { z: 45 }
  angle_limit { min: -70.0 max: -30.0 }
  angular_damping: 20
}
joints {
  name: "hip_3"
  parent_offset { x: -0.2 y: -0.2 }
  child_offset { x: 0.1 y: 0.1 }
  parent: "$ Torso"
  child: "Aux 3"
  rotation { y: -90 }
  angle_limit { min: -30.0 max: 30.0 }
  angular_damping: 20
}
joints {
  name: "ankle_3"
  parent_offset { x: -0.1 y: -0.1 }
  child_offset {
    x: 0.2
    y: 0.2
  }
  parent: "Aux 3"
  child: "$ Body 10"
  rotation { z: 135 }
  angle_limit { min: -70.0 max: -30.0 }
  angular_damping: 20
}
joints {
  name: "hip_4"
  parent_offset { x: 0.2 y: -0.2 }
  child_offset { x: -0.1 y: 0.1 }
  parent: "$ Torso"
  child: "Aux 4"
  rotation { y: -90 }
  angle_limit { min: -30.0 max: 30.0 }
  angular_damping: 20
}
joints {
  name: "ankle_4"
  parent_offset { x: 0.1 y: -0.1 }
  child_offset { x: -0.2 y: 0.2 }
  parent: "Aux 4"
  child: "$ Body 13"
  rotation { z: 45 }
  angle_limit { min: 30.0 max: 70.0 }
  angular_damping: 20
}
actuators {
  name: "hip_1"
  joint: "hip_1"
  strength: 350.0
  torque {}
}
actuators {
  name: "ankle_1"
  joint: "ankle_1"
  strength: 350.0
  torque {}
}
actuators {
  name: "hip_2"
  joint: "hip_2"
  strength: 350.0
  torque {}
}
actuators {
  name: "ankle_2"
  joint: "ankle_2"
  strength: 350.0
  torque {}
}
actuators {
  name: "hip_3"
  joint: "hip_3"
  strength: 350.0
  torque {}
}
actuators {
  name: "ankle_3"
  joint: "ankle_3"
  strength: 350.0
  torque {}
}
actuators {
  name: "hip_4"
  joint: "hip_4"
  strength: 350.0
  torque {}
}
actuators {
  name: "ankle_4"
  joint: "ankle_4"
  strength: 350.0
  torque {}
}
friction: 1.0
gravity { z: -9.8 }
angular_damping: -0.05
collide_include {
  first: "$ Torso"
  second: "Ground"
}
collide_include {
  first: "$ Body 4"
  second: "Ground"
}
collide_include {
  first: "$ Body 7"
  second: "Ground"
}
collide_include {
  first: "$ Body 10"
  second: "Ground"
}
collide_include {
  first: "$ Body 13"
  second: "Ground"
}
dt: 0.05
substeps: 10
dynamics_mode: "pbd"
"""

_SYSTEM_CONFIG_SPRING = """
bodies {
name: "$ Torso"
colliders {
  capsule {
    radius: 0.25
    length: 0.5
    end: 1
  }
}
inertia { x: 1.0 y: 1.0 z: 1.0 }
mass: 10
}
bodies {
name: "Aux 1"
colliders {
  rotation { x: 90 y: -45 }
  capsule {
    radius: 0.08
    length: 0.4428427219390869
  }
}
inertia { x: 1.0 y: 1.0 z: 1.0 }
mass: 1
}
bodies {
name: "$ Body 4"
colliders {
  rotation { x: 90 y: -45 }
  capsule {
    radius: 0.08
    length: 0.7256854176521301
    end: -1
  }
}
inertia { x: 1.0 y: 1.0 z: 1.0 }
mass: 1
}
bodies {
name: "Aux 2"
colliders {
  rotation { x: 90 y: 45 }
  capsule {
    radius: 0.08
    length: 0.4428427219390869
  }
}
inertia { x: 1.0 y: 1.0 z: 1.0 }
mass: 1
}
bodies {
name: "$ Body 7"
colliders {
  rotation { x: 90 y: 45 }
  capsule {
    radius: 0.08
    length: 0.7256854176521301
    end: -1
  }
}
inertia { x: 1.0 y: 1.0 z: 1.0 }
mass: 1
}
bodies {
name: "Aux 3"
colliders {
  rotation { x: -90 y: 45 }
  capsule {
    radius: 0.08
    length: 0.4428427219390869
  }
}
inertia { x: 1.0 y: 1.0 z: 1.0 }
mass: 1
}
bodies {
name: "$ Body 10"
colliders {
  rotation { x: -90 y: 45 }
  capsule {
    radius: 0.08
    length: 0.7256854176521301
    end: -1
  }
}
inertia { x: 1.0 y: 1.0 z: 1.0 }
mass: 1
}
bodies {
name: "Aux 4"
colliders {
  rotation { x: -90 y: -45 }
  capsule {
    radius: 0.08
    length: 0.4428427219390869
  }
}
inertia { x: 1.0 y: 1.0 z: 1.0 }
mass: 1
}
bodies {
name: "$ Body 13"
colliders {
  rotation { x: -90 y: -45 }
  capsule {
    radius: 0.08
    length: 0.7256854176521301
    end: -1
  }
}
inertia { x: 1.0 y: 1.0 z: 1.0 }
mass: 1
}
bodies {
name: "Ground"
colliders {
  plane {}
}
inertia { x: 1.0 y: 1.0 z: 1.0 }
mass: 1
frozen { all: true }
}
joints {
name: "$ Torso_Aux 1"
parent_offset { x: 0.2 y: 0.2 }
child_offset { x: -0.1 y: -0.1 }
parent: "$ Torso"
child: "Aux 1"
stiffness: 18000.0
angular_damping: 20
spring_damping: 80
angle_limit { min: -30.0 max: 30.0 }
rotation { y: -90 }
}
joints {
name: "Aux 1_$ Body 4"
parent_offset { x: 0.1 y: 0.1 }
child_offset { x: -0.2 y: -0.2 }
parent: "Aux 1"
child: "$ Body 4"
stiffness: 18000.0
angular_damping: 20
spring_damping: 80
rotation: { z: 135 }
angle_limit {
  min: 30.0
  max: 70.0
}
}
joints {
name: "$ Torso_Aux 2"
parent_offset { x: -0.2 y: 0.2 }
child_offset { x: 0.1 y: -0.1 }
parent: "$ Torso"
child: "Aux 2"
stiffness: 18000.0
angular_damping: 20
spring_damping: 80
rotation { y: -90 }
angle_limit { min: -30.0 max: 30.0 }
}
joints {
name: "Aux 2_$ Body 7"
parent_offset { x: -0.1 y: 0.1 }
child_offset { x: 0.2 y: -0.2 }
parent: "Aux 2"
child: "$ Body 7"
stiffness: 18000.0
angular_damping: 20
spring_damping: 80
rotation { z: 45 }
angle_limit { min: -70.0 max: -30.0 }
}
joints {
name: "$ Torso_Aux 3"
parent_offset { x: -0.2 y: -0.2 }
child_offset { x: 0.1 y: 0.1 }
parent: "$ Torso"
child: "Aux 3"
stiffness: 18000.0
angular_damping: 20
spring_damping: 80
rotation { y: -90 }
angle_limit { min: -30.0 max: 30.0 }
}
joints {
name: "Aux 3_$ Body 10"
parent_offset { x: -0.1 y: -0.1 }
child_offset {
  x: 0.2
  y: 0.2
}
parent: "Aux 3"
child: "$ Body 10"
stiffness: 18000.0
angular_damping: 20
spring_damping: 80
rotation { z: 135 }
angle_limit { min: -70.0 max: -30.0 }
}
joints {
name: "$ Torso_Aux 4"
parent_offset { x: 0.2 y: -0.2 }
child_offset { x: -0.1 y: 0.1 }
parent: "$ Torso"
child: "Aux 4"
stiffness: 18000.0
angular_damping: 20
spring_damping: 80
rotation { y: -90 }
angle_limit { min: -30.0 max: 30.0 }
}
joints {
name: "Aux 4_$ Body 13"
parent_offset { x: 0.1 y: -0.1 }
child_offset { x: -0.2 y: 0.2 }
parent: "Aux 4"
child: "$ Body 13"
stiffness: 18000.0
angular_damping: 20
spring_damping: 80
rotation { z: 45 }
angle_limit { min: 30.0 max: 70.0 }
}
actuators {
name: "$ Torso_Aux 1"
joint: "$ Torso_Aux 1"
strength: 350.0
torque {}
}
actuators {
name: "Aux 1_$ Body 4"
joint: "Aux 1_$ Body 4"
strength: 350.0
torque {}
}
actuators {
name: "$ Torso_Aux 2"
joint: "$ Torso_Aux 2"
strength: 350.0
torque {}
}
actuators {
name: "Aux 2_$ Body 7"
joint: "Aux 2_$ Body 7"
strength: 350.0
torque {}
}
actuators {
name: "$ Torso_Aux 3"
joint: "$ Torso_Aux 3"
strength: 350.0
torque {}
}
actuators {
name: "Aux 3_$ Body 10"
joint: "Aux 3_$ Body 10"
strength: 350.0
torque {}
}
actuators {
name: "$ Torso_Aux 4"
joint: "$ Torso_Aux 4"
strength: 350.0
torque {}
}
actuators {
name: "Aux 4_$ Body 13"
joint: "Aux 4_$ Body 13"
strength: 350.0
torque {}
}
friction: 1.0
gravity { z: -9.8 }
angular_damping: -0.05
baumgarte_erp: 0.1
collide_include {
first: "$ Torso"
second: "Ground"
}
collide_include {
first: "$ Body 4"
second: "Ground"
}
collide_include {
first: "$ Body 7"
second: "Ground"
}
collide_include {
first: "$ Body 10"
second: "Ground"
}
collide_include {
first: "$ Body 13"
second: "Ground"
}
dt: 0.05
substeps: 10
dynamics_mode: "legacy_spring"
"""

environment = "ant"  # @param ['ant', 'halfcheetah', 'hopper', 'humanoid', 'reacher', 'walker2d', 'fetch', 'grasp', 'ur5e']
env = envs.create(env_name=environment)
state = env.reset(rng=jp.random_prngkey(seed=0))

with open('viz.html', 'w') as f:
f.write(html.render(env.sys, []))

Thank you for your time.

[chenyu32]

HI, sorry for the wordy message above. I finally managed to get a visulisation working for "ur5". The other thing is can I load urdf in brax which I used for my "Franka Emika Panda" Robotic arm?

Thank you very much.