Merge pull request #371 from ami-iit/flferretti-patch-3

Avoid unnecessary dynamics computation in RNEA-related functions
ami-iit · Feb 11, 2025 · cf5f4a5 · cf5f4a5
2 parents 0020a58 + 5c89223
commit cf5f4a5
Showing 1 changed file with 6 additions and 13 deletions.
diff --git a/src/jaxsim/api/model.py b/src/jaxsim/api/model.py
@@ -1420,14 +1420,10 @@ def free_floating_gravity_forces(
         The free-floating gravity forces of the model.
     """
 
-    # Build a zeroed state.
-    data_rnea = js.data.JaxSimModelData.zero(
-        model=model, velocity_representation=data.velocity_representation
-    )
-
-    # Set just the generalized position.
-    data_rnea = data_rnea.replace(
+    # Build a new state with zeroed velocities.
+    data_rnea = js.data.JaxSimModelData.build(
         model=model,
+        velocity_representation=data.velocity_representation,
         base_position=data.base_position,
         base_quaternion=data.base_quaternion,
         joint_positions=data.joint_positions,
@@ -1462,19 +1458,16 @@ def free_floating_bias_forces(
         The free-floating bias forces of the model.
     """
 
-    # Build a zeroed state.
-    data_rnea = js.data.JaxSimModelData.zero(
-        model=model, velocity_representation=data.velocity_representation
-    )
-
     # Set the generalized position and generalized velocity.
     base_linear_velocity, base_angular_velocity = None, None
     if model.floating_base():
         base_velocity = data.base_velocity
         base_linear_velocity = base_velocity[:3]
         base_angular_velocity = base_velocity[3:]
-    data_rnea = data_rnea.replace(
+
+    data_rnea = js.data.JaxSimModelData.build(
         model=model,
+        velocity_representation=data.velocity_representation,
         base_position=data.base_position,
         base_quaternion=data.base_quaternion,
         joint_positions=data.joint_positions,