Add docs for simulator callbacks and physics model input

src/jaxsim/physics/model/physics_model_state.py

@@ -129,6 +129,16 @@ def valid(
 
 @jax_dataclasses.pytree_dataclass
 class PhysicsModelInput(JaxsimDataclass):
+    """
+    A class representing the input to a physics model.
+
+    This class stores the joint torques and external forces acting on the bodies of a physics model.
+
+    Attributes:
+        tau (jtp.Vector): An array representing the joint torques.
+        f_ext (jtp.Matrix): A matrix representing the external forces acting on the bodies of the physics model.
+    """
+
     tau: jtp.VectorJax
     f_ext: jtp.MatrixJax
 

src/jaxsim/simulation/simulator_callbacks.py

@@ -14,10 +14,16 @@
 
 
 class SimulatorCallback(abc.ABC):
+    """
+    A base class for simulator callbacks.
+    """
     pass
 
 
 class ConfigureCallback(SimulatorCallback):
+    """
+    A class for configuring a simulator callback.
+    """
     @property
     def configure_cb(self) -> ConfigureCallbackSignature:
         return lambda sim: self.configure(sim=sim)
@@ -28,6 +34,9 @@ def configure(self, sim: "jaxsim.JaxSim") -> "jaxsim.JaxSim":
 
 
 class PreStepCallback(SimulatorCallback):
+    """
+    A callback class for performing actions before each simulation step.
+    """
     @property
     def pre_step_cb(self) -> PreStepCallbackSignature:
         return lambda sim: self.pre_step(sim=sim)
@@ -38,6 +47,10 @@ def pre_step(self, sim: "jaxsim.JaxSim") -> Tuple["jaxsim.JaxSim", jtp.PyTree]:
 
 
 class PostStepCallback(SimulatorCallback):
+    """
+    A callback class for performing actions after each simulation step.
+    """
+
     @property
     def post_step_cb(self) -> PostStepCallbackSignature:
         return lambda sim, step_data: self.post_step(sim=sim, step_data=step_data)
@@ -50,4 +63,7 @@ def post_step(
 
 
 class CallbackHandler(ConfigureCallback, PreStepCallback, PostStepCallback):
+    """
+    A class that handles callbacks for the simulator.
+    """
     pass