Added docs

docs/source/how-to/index.rst

@@ -36,6 +36,17 @@ a fixed base robot. This guide goes over the various considerations and steps to
 
     make_fixed_prim
 
+Multi-Asset Spawning
+--------------------
+
+This guide explains how to import and configure different assets in each environment. This is
+useful when you want to create diverse environments with different objects.
+
+.. toctree::
+    :maxdepth: 1
+
+    multi_asset_spawning
+
 Saving Camera Output
 --------------------
 

docs/source/how-to/multi_asset_spawning.rst

@@ -0,0 +1,72 @@
+Spawning Multiple Assets
+========================
+
+.. currentmodule:: omni.isaac.lab
+
+This guide describes how to create different assets within each environment using spawning functions that allow for random selection of assets.
+The approach is useful to create diversity in your simulations. The sample script ``multi_asset.py`` is used as a reference, located in the ``IsaacLab/source/standalone/demos`` directory.
+
+.. dropdown:: Code for multi_asset.py
+   :icon: code
+
+   .. literalinclude:: ../../../source/standalone/demos/multi_asset.py
+      :language: python
+      :linenos:
+
+This script creates multiple environments, where each environment has a rigid object that is either a cone, a cube, or a sphere,
+and an articulation that is either the ANYmal-C or ANYmal-D robot.
+
+.. image:: ../_static/demos/multi_asset.jpg
+  :width: 100%
+  :alt: result of multi_asset.py
+
+Using Multi-Asset Spawning Functions
+------------------------------------
+
+It is possible to spawn different assets and USDs in each environment using the spawners :class:`~sim.spawners.wrappers.MultiAssetSpawnerCfg` and :class:`~sim_utils.MultiUsdFileCfg`:
+
+* We set the spawn configuration in :class:`~RigidObjectCfg` to be :class:`~sim.spawners.wrappers.MultiAssetSpawnerCfg`:
+
+  .. literalinclude:: ../../../source/standalone/demos/multi_asset.py
+     :language: python
+     :lines: 99-125
+     :dedent:
+
+  This function allows you to define a list of different assets that can be spawned as rigid objects.
+  When ``random_choice=True`` is set, one asset from the list is randomly selected each time an object is spawned.
+
+* We set the spawn configuration in :class:`~ArticulationCfg` to be :class:`~sim_utils.MultiUsdFileCfg`:
+
+  .. literalinclude:: ../../../source/standalone/demos/multi_asset.py
+     :language: python
+     :lines: 128-161
+     :dedent:
+
+  This configuration allows the selection of different USD files representing articulated assets.
+  With ``random_choice=True``, the spawning process picks one of the specified assets at random. In the following scenario,
+  it is important to note that the articulation must have the same structure (same links, joints, names, etc.) across all USD files.
+  The purpose is to enable the user to create randomized versions of the same asset, for example with different link lengths.
+
+
+
+Executing the Simulation
+------------------------
+
+To execute the script with multiple environments and randomized assets, use the following command:
+
+.. code-block:: bash
+
+  ./isaaclab.sh -p source/standalone/demos/multi_asset.py --num_envs 2048
+
+This command runs the simulation with 2048 environments, each with randomly selected assets.
+
+Stopping the Simulation
+-----------------------
+
+To stop the simulation, use the following command in the terminal:
+
+.. code-block:: bash
+
+  Ctrl+C
+
+This safely terminates the simulation.