Spawn two robots from URDF files, without robot_state_publisher node (spawn_entity.py script with argument -file instead of -topic)

spawn_two_urdf_robots.launch.py

import os
from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
from launch.substitutions import Command, LaunchConfiguration
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch_ros.actions import Node
from ament_index_python.packages import get_package_share_directory


def generate_launch_description():
    
    # This is to find the models inside the models folder in my_box_bot_gazebo package
    gazebo_models_path = os.path.join(pkg_box_bot_gazebo, 'models')
    if 'GAZEBO_MODEL_PATH' in os.environ:
        os.environ['GAZEBO_MODEL_PATH'] = os.environ['GAZEBO_MODEL_PATH'] + \
            ':' + install_dir + '/share' + ':' + gazebo_models_path
    else:
        os.environ['GAZEBO_MODEL_PATH'] = install_dir + \
            "/share" + ':' + gazebo_models_path

    if 'GAZEBO_PLUGIN_PATH' in os.environ:
        os.environ['GAZEBO_PLUGIN_PATH'] = os.environ['GAZEBO_PLUGIN_PATH'] + \
            ':' + install_dir + '/lib'
    else:
        os.environ['GAZEBO_PLUGIN_PATH'] = install_dir + '/lib'

    print("GAZEBO MODELS PATH=="+str(os.environ["GAZEBO_MODEL_PATH"]))
    print("GAZEBO PLUGINS PATH=="+str(os.environ["GAZEBO_PLUGIN_PATH"]))

    # Declare a new launch argument for the world file
    world_file_arg = DeclareLaunchArgument(
        'world',
        default_value=[get_package_share_directory(
            'my_box_bot_gazebo'), '/worlds/box_bot_empty.world'],
        description='Path to the Gazebo world file'
    )

    # Define the launch arguments for the Gazebo launch file
    gazebo_launch_args = {
        'verbose': 'false',
        'pause': 'false',
        'world': LaunchConfiguration('world')
    }

   # Include the Gazebo launch file with the modified launch arguments
    gazebo = IncludeLaunchDescription(
        PythonLaunchDescriptionSource([os.path.join(
            get_package_share_directory('gazebo_ros'), 'launch'), '/gazebo.launch.py']),
        launch_arguments=gazebo_launch_args.items(),
    )

    spawn_robot1 = Node(
        package='gazebo_ros',
        executable='spawn_entity.py',
        arguments=['-entity', 'robot1', '-x', '0.0', '-y', '0.0', '-z', '0.0',
                   '-file', get_package_share_directory('my_box_bot_description') + '/urdf/box_bot_final.urdf'],
    )

    spawn_robot2 = Node(
        package='gazebo_ros',
        executable='spawn_entity.py',
        arguments=['-entity', 'robot2', '-x', '1.0', '-y', '1.0', '-z', '0.0',
                   '-file', get_package_share_directory('my_box_bot_description') + '/urdf/box_bot_final.urdf'],
    )

    return LaunchDescription([
        world_file_arg,
        gazebo,
        spawn_robot1,
        spawn_robot2
    ])