Refactor CosseratBase and tutorial scenes to update parameter handlin…

…g and fix typos

- Changed 'beam_params' to 'params' in CosseratBase for better clarity.
- Updated parameter references in tutorial scenes (tuto_4.py, tuto_5.py)
to match new naming conventions.
- Refined BeamPhysicsParameters to use NoInertia where applicable.
- Fixed typos (e.g., 'rotateFromEuler' comment and variable names like
'nbFrames' to 'nb_frames').
- Added rigid base spring force field in CosseratBase for better beam
control.
- Organized imports and cleaned up unused variables in the tutorial
scenes.

tutorial/tuto_scenes/tuto_4.py

@@ -10,22 +10,25 @@
 __date__ = "October, 26 2021"
 
 from useful.header import addHeader, addSolverNode
-from useful.params import BeamPhysicsParameters, BeamGeometryParameters, SimulationParameters
+from useful.params import BeamPhysicsParametersNoInertia, BeamGeometryParameters, SimulationParameters
 from useful.params import Parameters
 from cosserat.CosseratBase import CosseratBase
 from math import sqrt
 from splib3.numerics import Quat
 import Sofa
 from math import pi
 
-geoParams = BeamGeometryParameters(init_pos=[0., 0., 0.], beamLength=30., showFramesObject=1,
-                                   nbSection=6, nbFrames=12, buildCollisionModel=0)
-physicsParams = BeamPhysicsParameters(beamMass=1., youngModulus=1.0e4, poissonRatio=0.38, beamRadius=0.5,
-                                      beamLength=30)
+_beam_radius = 0.5
+_beam_length = 30.
+_nb_section = 32
+force_null = [0., 0., 0., 0., 0., 0.]  # N
+geoParams = BeamGeometryParameters(beam_length=30.,
+                                   nb_section=_nb_section, nb_frames=_nb_section, build_collision_model=0)
+physicsParams = BeamPhysicsParametersNoInertia(beam_mass=1., young_modulus=1.0e4, poisson_ratio=0.38,
+                                               beam_radius=_beam_radius, beam_length=30)
 simuParams = SimulationParameters()
-Params = Parameters(beamGeoParams=geoParams, beamPhysicsParams=physicsParams, simuParams=simuParams)
+Params = Parameters(beam_geo_params=geoParams, beam_physics_params=physicsParams, simu_params=simuParams)
 
-force_null = [0., 0., 0., 0., 0., 0.]  # N
 
 class ForceController(Sofa.Core.Controller):
     def __init__(self, *args, **kwargs):
@@ -35,7 +38,7 @@ def __init__(self, *args, **kwargs):
         self.force_type = kwargs['force_type']
         self.tip_controller = kwargs['tip_controller']
 
-        self.size = geoParams.nbFrames
+        self.size = geoParams.nb_frames
         self.applyForce = True
         self.forceCoeff = 0.
         self.theta = 0.1
@@ -60,7 +63,7 @@ def onAnimateEndEvent(self, event):
 
     def compute_force(self):
         with self.forceNode.forces.writeable() as force:
-            vec = [0., 0., 0., 0., self.forceCoeff/sqrt(2), self.forceCoeff/sqrt(2)]
+            vec = [0., 0., 0., 0., self.forceCoeff / sqrt(2), self.forceCoeff / sqrt(2)]
             for i, v in enumerate(vec):
                 force[0][i] = v
 
@@ -82,7 +85,7 @@ def rotate_force(self):
                 last_frame = self.frames.position[self.size]
                 vec = Quat(last_frame[3], last_frame[4], last_frame[5], last_frame[6])  # get the orientation
 
-                vec.rotateFromEuler([self.theta, 0., 0.])  # apply rotation arround x-axis 
+                vec.rotateFromEuler([self.theta, 0., 0.])  # apply rotation around x-axis
                 vec.normalize()
                 for i, v in enumerate(vec):
                     position[0][i + 3] = v
@@ -95,7 +98,8 @@ def onKeypressedEvent(self, event):
             self.applyForce = False
 
 
-controller_type = 1
+controller_type: int = 1
+
 
 def createScene(root_node):
     addHeader(root_node)
@@ -105,22 +109,33 @@ def createScene(root_node):
 
     # create cosserat Beam
     cosserat_beam = solver_node.addChild(CosseratBase(parent=solver_node, params=Params))
+    cosserat_beam.rigidBaseNode.addObject(
+        "RestShapeSpringsForceField",
+        name="spring",
+        stiffness=1e8,
+        angularStiffness=1.0e8,
+        external_points=0,
+        points=0,
+        template="Rigid3d"
+    )
     cosserat_frames = cosserat_beam.cosseratFrame
 
     # this constance force is used only in the case we are doing force_type 1 or 2
-    const_force_node = cosserat_frames.addObject('ConstantForceField', name='constForce', showArrowSize=1.e-8, indices=geoParams.nbFrames, forces=force_null)
+    const_force_node = cosserat_frames.addObject('ConstantForceField', name='constForce', showArrowSize=1.e-8,
+                                                 indices=geoParams.nb_frames, forces=force_null)
 
     # The effector is used only when force_type is 3
     # create a rigid body to control the end effector of the beam
     tip_controller = root_node.addChild('tip_controller')
     controller_state = tip_controller.addObject('MechanicalObject', template='Rigid3d', name="controlEndEffector",
-                                                showObjectScale=0.3, position=[geoParams.beamLength, 0, 0, 0, 0, 0, 1],
+                                                showObjectScale=0.3, position=[geoParams.beam_length, 0, 0, 0, 0, 0, 1],
                                                 showObject=True)
     if controller_type == 3:
         cosserat_frames.addObject('RestShapeSpringsForceField', name='spring', stiffness=0., angularStiffness=1.e8,
                                   external_points=0, external_rest_shape=controller_state.getLinkPath(),
-                                  points=geoParams.nbFrames, template="Rigid3d")
+                                  points=geoParams.nb_frames, template="Rigid3d")
 
-    solver_node.addObject(ForceController(forceNode=const_force_node, frame_node=cosserat_frames, force_type=controller_type, tip_controller=controller_state))
+    solver_node.addObject(ForceController(forceNode=const_force_node, frame_node=cosserat_frames,
+                                          force_type=controller_type, tip_controller=controller_state))
 
     return root_node

tutorial/tuto_scenes/tuto_5.py

@@ -9,16 +9,15 @@
 __copyright__ = "(c) 2021,Inria"
 __date__ = "October, 26 2021"
 
-from useful.header import addHeader, addSolverNode, addVisual
-from useful.params import BeamPhysicsParametersNoInertia , BeamGeometryParameters, SimulationParameters
+from useful.header import addHeader, addSolverNode, Finger
+from useful.params import BeamPhysicsParametersNoInertia, BeamGeometryParameters, SimulationParameters
 from useful.params import Parameters
 from cosserat.CosseratBase import CosseratBase
 from math import sqrt
 from splib3.numerics import Quat
 import Sofa
 import os
 from math import pi
-from useful.header import addHeader, addVisual, addSolverNode, Finger
 from controller import FingerController
 from numpy import array