[Kamino] Remove unused inertia statistics (#3542)

Author: rubengrandia

newton/_src/solvers/kamino/_src/core/builder.py

@@ -979,10 +979,6 @@ def finalize(
         info_jkcio = []
         info_base_bid = []
         info_base_jid = []
-        info_mass_min = []
-        info_mass_max = []
-        info_mass_total = []
-        info_inertia_total = []
 
         # Initialize the gravity data collections
         gravity_g_dir_acc = []
@@ -1087,12 +1083,6 @@ def collect_model_info_data():
                 info_jio.append(world.joints_idx_offset)
                 info_gio.append(world.geoms_idx_offset)
 
-                # Collect the model mass and inertia data
-                info_mass_min.append(world.mass_min)
-                info_mass_max.append(world.mass_max)
-                info_mass_total.append(world.mass_total)
-                info_inertia_total.append(world.inertia_total)
-
             # Collect the index offsets for bodies and joints
             for world in self._worlds:
                 info_bdio.append(world.body_dofs_idx_offset)
@@ -1366,10 +1356,6 @@ def collect_material_pairs_model_data():
                 joint_kinematic_cts_offset=to_warp_int32_array(info_jkcio),
                 base_body_index=to_warp_int32_array(info_base_bid),
                 base_joint_index=to_warp_int32_array(info_base_jid),
-                mass_min=wp.array(info_mass_min, dtype=wp.float32),
-                mass_max=wp.array(info_mass_max, dtype=wp.float32),
-                mass_total=wp.array(info_mass_total, dtype=wp.float32),
-                inertia_total=wp.array(info_inertia_total, dtype=wp.float32),
             )
 
             # Create the model time data

newton/_src/solvers/kamino/_src/core/conversions.py

@@ -124,45 +124,6 @@ def rigid_bodies_indexing_kernel(
     world_body_dof_offset[world_id] = 6 * model_body_world_start[world_id]
 
 
-@wp.kernel
-def mass_prop_accumulation_kernel(
-    # Inputs:
-    model_body_world_start: wp.array[wp.int32],
-    model_body_mass: wp.array[wp.float32],
-    body_inertia: wp.array[wp.mat33f],
-    # Outputs:
-    mass_total: wp.array[wp.float32],
-    mass_min: wp.array[wp.float32],
-    mass_max: wp.array[wp.float32],
-    inertia_total: wp.array[wp.float32],
-):
-    # Retrieve the world index
-    world_id = wp.tid()
-    # Retrieve the body index range for this world
-    body_id_start = model_body_world_start[world_id]
-    body_id_end = model_body_world_start[world_id + 1] - 1
-
-    mass = wp.float32(0.0)
-    m_min = wp.float32(1e10)
-    m_max = wp.float32(0.0)
-    inertia = wp.float32(0.0)
-
-    for body_id in range(body_id_start, body_id_end + 1):
-        mass_b = model_body_mass[body_id]
-        mass += mass_b
-        if mass_b < m_min:
-            m_min = mass_b
-        if mass_b > m_max:
-            m_max = mass_b
-        inertia_diag = wp.get_diag(body_inertia[body_id])
-        inertia += 3.0 * mass_b + inertia_diag[0] + inertia_diag[1] + inertia_diag[2]
-
-    mass_total[world_id] = mass
-    mass_min[world_id] = m_min
-    mass_max[world_id] = m_max
-    inertia_total[world_id] = inertia
-
-
 @wp.kernel
 def joint_conversion_kernel(
     # Inputs:
@@ -741,29 +702,6 @@ def convert_rigid_bodies(
         device=model.device,
     )
 
-    # Construct per-world inertial summaries
-    with wp.ScopedDevice(model.device):
-        mass_total = wp.empty((model.world_count,), dtype=wp.float32)
-        mass_min = wp.empty((model.world_count,), dtype=wp.float32)
-        mass_max = wp.empty((model.world_count,), dtype=wp.float32)
-        inertia_total = wp.empty((model.world_count,), dtype=wp.float32)
-    wp.launch(
-        kernel=mass_prop_accumulation_kernel,
-        dim=model.world_count,
-        inputs=[
-            model.body_world_start,
-            model.body_mass,
-            model.body_inertia,
-        ],
-        outputs=[
-            mass_total,
-            mass_min,
-            mass_max,
-            inertia_total,
-        ],
-        device=model.device,
-    )
-
     # model.body_q stores body-origin world poses, but Kamino expects
     # COM world poses (joint attachment vectors are COM-relative).
     q_i_0 = wp.empty((model.body_count,), dtype=wp.transformf, device=model.device)
@@ -792,10 +730,6 @@ def convert_rigid_bodies(
     model_info.bodies_offset = world_body_offset
     model_info.geoms_offset = world_shape_offset
     model_info.body_dofs_offset = world_body_dof_offset
-    model_info.mass_min = mass_min
-    model_info.mass_max = mass_max
-    model_info.mass_total = mass_total
-    model_info.inertia_total = inertia_total
 
     model_bodies = RigidBodiesModel(
         num_bodies=model.body_count,

newton/_src/solvers/kamino/_src/core/model.py

@@ -401,34 +401,6 @@ class ModelKaminoInfo:
     Shape of ``(num_worlds,)``.
     """
 
-    ###
-    # Inertial Properties
-    ###
-
-    mass_min: wp.array[wp.float32] | None = None
-    """
-    Smallest mass amongst all bodies in each world.
-    Shape of ``(num_worlds,)``.
-    """
-
-    mass_max: wp.array[wp.float32] | None = None
-    """
-    Largest mass amongst all bodies in each world.
-    Shape of ``(num_worlds,)``.
-    """
-
-    mass_total: wp.array[wp.float32] | None = None
-    """
-    Total mass over all bodies in each world.
-    Shape of ``(num_worlds,)``.
-    """
-
-    inertia_total: wp.array[wp.float32] | None = None
-    """
-    Total diagonal inertia over all bodies in each world.
-    Shape of ``(num_worlds,)``.
-    """
-
 
 @dataclass
 class ModelKamino:

newton/_src/solvers/kamino/solver_kamino.py

@@ -1162,8 +1162,8 @@ def _check_dynamic_constraint_topology(self) -> None:
             joint = int(changed[0])  # report only first violation
             raise RuntimeError(
                 f"Changing dynamic constraint topology for joint {joint} "
-                f"({self.model.joint_label[joint]!r}) is not supported; recreate SolverKamino to apply the change."
-                "The dynamic constraint topology changes if armature, damping, target stiffness, or target damping are updated to non-zero values, while they were zero when creating the solver."
+                f"({self.model.joint_label[joint]!r}) is not supported; recreate SolverKamino to apply the change. "
+                "The dynamic constraint topology changes if armature, damping, target stiffness, or target damping are updated to non-zero values, while they were zero when creating the solver. "
                 "The opposite is also true: if the values are updated to zero, while they were non-zero when creating the solver, the dynamic constraint topology also changes."
             )
 

newton/_src/solvers/kamino/tests/utils/checks.py

@@ -406,10 +406,6 @@ def assert_model_info_equal(
         "joint_kinematic_cts_group_offset",
         "base_body_index",
         "base_joint_index",
-        "mass_min",
-        "mass_max",
-        "mass_total",
-        "inertia_total",
     ]
     if excluded:
         array_attributes = [attr for attr in array_attributes if attr not in excluded]

newton/_src/solvers/kamino/tests/utils/print.py

@@ -91,12 +91,6 @@ def print_model_info(model: ModelKamino):
     print(f"model.info.total_cts_offset: {model.info.total_cts_offset}")
     print(f"model.info.joint_dynamic_cts_group_offset: {model.info.joint_dynamic_cts_group_offset}")
     print(f"model.info.joint_kinematic_cts_group_offset: {model.info.joint_kinematic_cts_group_offset}")
-    # Print the inertial properties
-    print("-------------------------------------------------------------------------------")
-    print(f"model.info.mass_min: {model.info.mass_min}")
-    print(f"model.info.mass_max: {model.info.mass_max}")
-    print(f"model.info.mass_total: {model.info.mass_total}")
-    print(f"model.info.inertia_total: {model.info.inertia_total}")
 
 
 def print_model_constraint_info(model: ModelKamino):