Tutorial for Freespace Segmentation with Isaac Sim
==================================================

.. figure:: :ir_lfs:`<resources/isaac_ros_docs/repositories_and_packages/isaac_ros_freespace_segmentation/Isaac_sim_tutorial.gif>`
    :width: 600px
    :align: center

Overview
------------

This tutorial demonstrates how to use a `Isaac
Sim <https://developer.nvidia.com/isaac-sim>`__ and
:ir_repo:`isaac_ros_bi3d_freespace <isaac_ros_freespace_segmentation> <isaac_ros_bi3d_freespace>`
to create a local occupancy grid.

Tutorial Walkthrough
--------------------

1.  Complete steps 1-7 listed in the quickstart
    :ref:`here <repositories_and_packages/isaac_ros_freespace_segmentation/isaac_ros_bi3d_freespace/index:quickstart>`.
2.  Install and launch Isaac Sim following the steps in the :doc:`Isaac ROS Isaac Sim Setup Guide </getting_started/isaac_sim/index>`

3.  Disable the clock reset when simulation is stopped. Go to the
    *Stage* tab and select ``/World/ROS_Clock/isaac_read_simulation_time``,
    then untick the *Reset On Stop* checkbox.

    .. figure:: :ir_lfs:`<resources/isaac_ros_docs/repositories_and_packages/isaac_ros_freespace_segmentation/Isaac_sim_disable_clock_reset.png>`
        :width: 500px
        :align: center

4.  Press **Play** to start publishing data from Isaac Sim.

    .. figure:: :ir_lfs:`<resources/isaac_ros_docs/getting_started/isaac_sim_sample_scene.png>`
        :align: center
        :width: 600px

5.  Open a second terminal and attach to the container:

    .. code:: bash

       cd ${ISAAC_ROS_WS}/src/isaac_ros_common && \
       ./scripts/run_dev.sh

6.  In the second terminal, start the ``isaac_ros_bi3d`` node using the
    launch files:

    .. code:: bash

       ros2 launch isaac_ros_bi3d_freespace isaac_ros_bi3d_freespace_isaac_sim.launch.py \
       featnet_engine_file_path:=/tmp/models/bi3d/bi3dnet_featnet.plan \
       segnet_engine_file_path:=/tmp/models/bi3d/bi3dnet_segnet.plan \
       max_disparity_values:=32

    You should see a RViz window, as shown below:

    .. figure:: :ir_lfs:`<resources/isaac_ros_docs/repositories_and_packages/isaac_ros_freespace_segmentation/Isaac_sim_rviz.png>`
        :width: 500px
        :align: center

7.  Optionally, you can run the visualizer script to visualize the
    disparity image:

    .. code:: bash

       ros2 run isaac_ros_bi3d isaac_ros_bi3d_visualizer.py --disparity_topic bi3d_mask

    .. figure:: :ir_lfs:`<resources/isaac_ros_docs/repositories_and_packages/isaac_ros_freespace_segmentation/Visualizer_isaac_sim.png>`
        :width: 500px
        :align: center