alxbilger · Nov 4, 2026
diff --git a/Sofa/Component/IO/Mesh/src/sofa/component/io/mesh/MeshExporter.h b/Sofa/Component/IO/Mesh/src/sofa/component/io/mesh/MeshExporter.h
@@ -29,21 +29,6 @@
 #include <sofa/helper/OptionsGroup.h>
 #include <sofa/simulation/BaseSimulationExporter.h>
 
-///////////////////////////// FORWARD DECLARATION //////////////////////////////////////////////////
-namespace sofa::core
-{
-namespace objectmodel {
-    class Event ;
-}
-namespace behavior {
-    class BaseMechanicalState;
-}
-namespace topology {
-    class BaseMeshTopology ;
-}
-}
-
-
 ////////////////////////////////// DECLARATION /////////////////////////////////////////////////////
 namespace sofa::component::_meshexporter_
 {

diff --git a/Sofa/Component/Visual/src/sofa/component/visual/Visual3DText.h b/Sofa/Component/Visual/src/sofa/component/visual/Visual3DText.h
@@ -25,16 +25,6 @@
 #include <sofa/core/visual/VisualModel.h>
 #include <sofa/type/RGBAColor.h>
 
-namespace sofa::core::topology
-{
-    class BaseMeshTopology;
-} // namespace sofa::core::topology
-
-namespace sofa::core::behavior
-{
-    class BaseMechanicalState;
-} // namespace sofa::core::behavior
-
 namespace sofa::component::visual
 {
 

diff --git a/Sofa/GL/Component/Rendering3D/src/sofa/gl/component/rendering3d/PointSplatModel.h b/Sofa/GL/Component/Rendering3D/src/sofa/gl/component/rendering3d/PointSplatModel.h
@@ -27,16 +27,6 @@
 #include <sofa/core/topology/TopologyData.h>
 #include <sofa/type/RGBAColor.h>
 
-namespace sofa::core::topology
-{
-    class BaseMeshTopology;
-} // namespace sofa::core::topology
-
-namespace sofa::core::behavior
-{
-    class BaseMechanicalState;
-} // namespace sofa::core::behavior
-
 namespace sofa::gl::component::rendering3d
 {
 

diff --git a/Sofa/GL/Component/Rendering3D/src/sofa/gl/component/rendering3d/SlicedVolumetricModel.h b/Sofa/GL/Component/Rendering3D/src/sofa/gl/component/rendering3d/SlicedVolumetricModel.h
@@ -29,16 +29,6 @@
 #include <sofa/core/topology/TopologyData.h>
 #include <sofa/gl/template.h>
 
-namespace sofa::core::topology
-{
-    class BaseMeshTopology;
-} // namespace sofa::core::topology
-
-namespace sofa::core::behavior
-{
-    class BaseMechanicalState;
-} // namespace sofa::core::behavior
-
 namespace sofa::gl::component::rendering3d
 {
 

diff --git a/Sofa/framework/Core/CMakeLists.txt b/Sofa/framework/Core/CMakeLists.txt
@@ -83,11 +83,11 @@ set(HEADER_FILES
     ${SRC_ROOT}/behavior/BaseLocalMassMatrix.h
     ${SRC_ROOT}/behavior/BaseMass.h
     ${SRC_ROOT}/behavior/BaseMatrixLinearSystem.h
-    ${SRC_ROOT}/behavior/BaseMechanicalState.h
     ${SRC_ROOT}/behavior/BaseOrderingMethod.h
     ${SRC_ROOT}/behavior/BaseProjectiveConstraintSet.h
     ${SRC_ROOT}/behavior/BaseRotationFinder.h
     ${SRC_ROOT}/behavior/BaseVectorOperations.h
+    ${SRC_ROOT}/behavior/BaseVectorState.h
     ${SRC_ROOT}/behavior/BlocMatrixWriter.h
     ${SRC_ROOT}/behavior/BlockType.h
     ${SRC_ROOT}/behavior/Constraint.h
@@ -273,9 +273,9 @@ set(SOURCE_FILES
     ${SRC_ROOT}/behavior/BaseLinearSolver.cpp
     ${SRC_ROOT}/behavior/BaseMass.cpp
     ${SRC_ROOT}/behavior/BaseMatrixLinearSystem.cpp
-    ${SRC_ROOT}/behavior/BaseMechanicalState.cpp
     ${SRC_ROOT}/behavior/BaseOrderingMethod.cpp
     ${SRC_ROOT}/behavior/BaseProjectiveConstraintSet.cpp
+    ${SRC_ROOT}/behavior/BaseVectorState.cpp
     ${SRC_ROOT}/behavior/ConstraintCorrection.cpp
     ${SRC_ROOT}/behavior/ConstraintResolution.cpp
     ${SRC_ROOT}/behavior/ConstraintSolver.cpp
@@ -371,6 +371,7 @@ set(SOURCE_FILES
 
 set(DEPRECATED_DIR "compat/sofa/core")
 set(DEPRECATED_HEADER_FILES
+    ${DEPRECATED_DIR}/behavior/BaseMechanicalState.h
     ${DEPRECATED_DIR}/objectmodel/BaseObject.h
 )
 

diff --git a/Sofa/framework/Core/compat/sofa/core/behavior/BaseMechanicalState.h b/Sofa/framework/Core/compat/sofa/core/behavior/BaseMechanicalState.h
@@ -0,0 +1,30 @@
+/******************************************************************************
+*                 SOFA, Simulation Open-Framework Architecture                *
+*                    (c) 2006 INRIA, USTL, UJF, CNRS, MGH                     *
+*                                                                             *
+* This program is free software; you can redistribute it and/or modify it     *
+* under the terms of the GNU Lesser General Public License as published by    *
+* the Free Software Foundation; either version 2.1 of the License, or (at     *
+* your option) any later version.                                             *
+*                                                                             *
+* This program is distributed in the hope that it will be useful, but WITHOUT *
+* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or       *
+* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License *
+* for more details.                                                           *
+*                                                                             *
+* You should have received a copy of the GNU Lesser General Public License    *
+* along with this program. If not, see <http://www.gnu.org/licenses/>.        *
+*******************************************************************************
+* Authors: The SOFA Team and external contributors (see Authors.txt)          *
+*                                                                             *
+* Contact information: contact@sofa-framework.org                             *
+******************************************************************************/
+#pragma once
+#include <sofa/core/behavior/BaseVectorState.h>
+
+namespace sofa::core::behavior
+{
+
+using BaseMechanicalState = BaseVectorState;
+
+}
diff --git a/...ofa/core/behavior/BaseMechanicalState.cpp → ...rc/sofa/core/behavior/BaseVectorState.cpp b/...ofa/core/behavior/BaseMechanicalState.cpp → ...rc/sofa/core/behavior/BaseVectorState.cpp
@@ -19,18 +19,18 @@
 *                                                                             *
 * Contact information: contact@sofa-framework.org                             *
 ******************************************************************************/
-#include <sofa/core/behavior/BaseMechanicalState.h>
+#include <sofa/core/behavior/BaseVectorState.h>
 #include <sofa/core/objectmodel/BaseNode.h>
 
 
 namespace sofa::core::behavior
 {
 
-BaseMechanicalState::BaseMechanicalState()
+BaseVectorState::BaseVectorState()
 {
 }
 
-BaseMechanicalState::~BaseMechanicalState()
+BaseVectorState::~BaseVectorState()
 {
 }
 
@@ -39,7 +39,7 @@ BaseMechanicalState::~BaseMechanicalState()
 /// This is used to compute in on steps operations such as $v = v + a*dt, x = x + v*dt$.
 /// Note that if the result vector appears inside the expression, it must be the first operand.
 /// By default this method decompose the computation into multiple vOp calls.
-void BaseMechanicalState::vMultiOp(const ExecParams* params, const VMultiOp& ops)
+void BaseVectorState::vMultiOp(const ExecParams* params, const VMultiOp& ops)
 {
     for (const auto& op : ops)
     {
@@ -79,25 +79,25 @@ void BaseMechanicalState::vMultiOp(const ExecParams* params, const VMultiOp& ops
 }
 
 /// Handle state Changes from a given Topology
-void BaseMechanicalState::handleStateChange(core::topology::Topology* /*t*/)
+void BaseVectorState::handleStateChange(core::topology::Topology* /*t*/)
 {
 //    if (t == this->getContext()->getTopology())
 //    {
         handleStateChange();
 //    }
 }
 
-void BaseMechanicalState::writeState( std::ostream& )
+void BaseVectorState::writeState( std::ostream& )
 { }
 
-bool BaseMechanicalState::insertInNode( objectmodel::BaseNode* node )
+bool BaseVectorState::insertInNode( objectmodel::BaseNode* node )
 {
     node->addMechanicalState(this);
     Inherit1::insertInNode(node);
     return true;
 }
 
-bool BaseMechanicalState::removeInNode( objectmodel::BaseNode* node )
+bool BaseVectorState::removeInNode( objectmodel::BaseNode* node )
 {
     node->removeMechanicalState(this);
     Inherit1::removeInNode(node);

diff --git a/.../sofa/core/behavior/BaseMechanicalState.h → .../src/sofa/core/behavior/BaseVectorState.h b/.../sofa/core/behavior/BaseMechanicalState.h → .../src/sofa/core/behavior/BaseVectorState.h
@@ -31,47 +31,20 @@
 namespace sofa::core::behavior
 {
 
-/**
- *  \brief Component storing all state vectors of a simulated body (position, velocity, etc).
- *
- *  This class only contains the data of the body and not any of its
- *  <i>active</i> computations, which are handled by the Mass, ForceField, and
- *  LagrangianConstraint components.
- *
- *  Two types of vectors are used :
- *  \li \code VecCoord \endcode : containing positions.
- *  \li \code VecDeriv \endcode : derivative values, i.e. velocity, forces, displacements.
- *  In most cases they are the same (i.e. 3D/2D point particles), but they can
- *  be different (rigid frames for instance).
- *
- *  Several pre-defined vectors are stored :
- *  \li \code position \endcode
- *  \li \code velocity \endcode
- *  \li \code force \endcode
- *  \li \code dx \endcode (displacement)
- *
- *  Other vectors can be allocated to store other temporary values.
- *  Vectors can be assigned efficiently by just swapping pointers.
- *
- *  In addition to state vectors, the current constraint system matrix is also
- *  stored, containing the coefficient of each constraint defined over the DOFs
- *  in this body.
- *
- */
-class SOFA_CORE_API BaseMechanicalState : public virtual BaseState
+class SOFA_CORE_API BaseVectorState : public virtual BaseState
 {
 public:
-    SOFA_ABSTRACT_CLASS(BaseMechanicalState, BaseState);
-    SOFA_BASE_CAST_IMPLEMENTATION(BaseMechanicalState);
+    SOFA_ABSTRACT_CLASS(BaseVectorState, BaseState);
+    SOFA_BASE_CAST_IMPLEMENTATION(BaseVectorState);
 
     using Index = sofa::Index;
 protected:
-    BaseMechanicalState();
+    BaseVectorState();
 
-    ~BaseMechanicalState() override;
+    ~BaseVectorState() override;
 private:
-    BaseMechanicalState(const BaseMechanicalState& n) = delete;
-    BaseMechanicalState& operator=(const BaseMechanicalState& n) = delete;
+    BaseVectorState(const BaseVectorState& n) = delete;
+    BaseVectorState& operator=(const BaseVectorState& n) = delete;
 
 public:
     /// @name Methods allowing to have access to the geometry without a template class (generic but not efficient)
@@ -299,7 +272,7 @@ class SOFA_CORE_API BaseMechanicalState : public virtual BaseState
     virtual bool pickParticles(const ExecParams* /* params */, double /*rayOx*/, double /*rayOy*/, double /*rayOz*/,
             double /*rayDx*/, double /*rayDy*/, double /*rayDz*/,
             double /*radius0*/, double /*dRadius*/,
-            std::multimap< double, std::pair<sofa::core::behavior::BaseMechanicalState*, int> >& /*particles*/)
+            std::multimap< double, std::pair<sofa::core::behavior::BaseVectorState*, int> >& /*particles*/)
     {
         return false;
     }

diff --git a/Sofa/framework/Core/src/sofa/core/behavior/fwd.h b/Sofa/framework/Core/src/sofa/core/behavior/fwd.h
@@ -32,6 +32,7 @@ namespace sofa::core::behavior
     class BaseInteractionForceField;
     class BaseInteractionProjectiveConstraintSet;
     class BaseMass;
-    class BaseMechanicalState;
+    class BaseVectorState;
+    using BaseMechanicalState = BaseVectorState;
     class MultiMatrixAccessor;
 }
diff --git a/Sofa/framework/Core/src/sofa/core/config.h.in b/Sofa/framework/Core/src/sofa/core/config.h.in
@@ -188,3 +188,10 @@ SOFA_ATTRIBUTE_DISABLED("v26.12", "v27.06", "Use solveLinearSystem instead of ac
 #define SOFA_CORE_DEPRECATED_GETDATAVECFROMMULTIVECID() \
 SOFA_ATTRIBUTE_DEPRECATED("v26.12", "v27.12", "")
 #endif
+
+#ifdef SOFA_BUILD_SOFA_CORE
+#define SOFA_ATTRIBUTE_DEPRECATED__TOBASEMECHANICALSTATE()
+#else
+#define SOFA_ATTRIBUTE_DEPRECATED__TOBASEMECHANICALSTATE() \
+    SOFA_ATTRIBUTE_DEPRECATED("v26.12", "v27.06", "Use toBaseVectorState instead.")
+#endif
diff --git a/Sofa/framework/Core/src/sofa/core/fwd.cpp b/Sofa/framework/Core/src/sofa/core/fwd.cpp
@@ -36,7 +36,7 @@
 #include <sofa/core/behavior/BaseMass.h>
 #include <sofa/core/behavior/BaseIntegrationScheme.h>
 #include <sofa/core/behavior/ConstraintSolver.h>
-#include <sofa/core/behavior/BaseMechanicalState.h>
+#include <sofa/core/behavior/BaseVectorState.h>
 #include <sofa/core/behavior/BaseForceField.h>
 #include <sofa/core/behavior/LinearSolver.h>
 #include <sofa/core/behavior/BaseConstraintSet.h>
@@ -174,7 +174,7 @@ SOFA_DEFINE_OPAQUE_FUNCTIONS_BETWEEN_BASE_AND(sofa::core::behavior::BaseMass);
 SOFA_DEFINE_OPAQUE_FUNCTIONS_BETWEEN_BASE_AND(sofa::core::behavior::BaseIntegrationScheme);
 SOFA_DEFINE_OPAQUE_FUNCTIONS_BETWEEN_BASE_AND(sofa::core::behavior::ConstraintSolver);
 SOFA_DEFINE_OPAQUE_FUNCTIONS_BETWEEN_BASE_AND(sofa::core::behavior::BaseLinearSolver);
-SOFA_DEFINE_OPAQUE_FUNCTIONS_BETWEEN_BASE_AND(sofa::core::behavior::BaseMechanicalState);
+SOFA_DEFINE_OPAQUE_FUNCTIONS_BETWEEN_BASE_AND(sofa::core::behavior::BaseVectorState);
 SOFA_DEFINE_OPAQUE_FUNCTIONS_BETWEEN_BASE_AND(sofa::core::behavior::BaseForceField);
 SOFA_DEFINE_OPAQUE_FUNCTIONS_BETWEEN_BASE_AND(sofa::core::behavior::BaseInteractionForceField);
 SOFA_DEFINE_OPAQUE_FUNCTIONS_BETWEEN_BASE_AND(sofa::core::behavior::BaseProjectiveConstraintSet);

diff --git a/Sofa/framework/Core/src/sofa/core/fwd.h b/Sofa/framework/Core/src/sofa/core/fwd.h
@@ -99,7 +99,8 @@ namespace sofa::core::behavior
 {
 class BaseForceField;
 class BaseMass;
-class BaseMechanicalState;
+class BaseVectorState;
+using BaseMechanicalState = BaseVectorState;
 class BaseAnimationLoop;
 class BaseLagrangianConstraint;
 class BaseConstraintSet;
@@ -111,7 +112,6 @@ class BaseInteractionForceField;
 class BaseProjectiveConstraintSet;
 class BaseInteractionProjectiveConstraintSet;
 class BaseInteractionConstraint;
-class BaseMechanicalState;
 class LinearSolver;
 class MultiMatrixAccessor;
 
@@ -276,7 +276,7 @@ SOFA_DECLARE_OPAQUE_FUNCTION_BETWEEN_BASE_AND(sofa::core::behavior::BaseMass);
 SOFA_DECLARE_OPAQUE_FUNCTION_BETWEEN_BASE_AND(sofa::core::behavior::BaseIntegrationScheme);
 SOFA_DECLARE_OPAQUE_FUNCTION_BETWEEN_BASE_AND(sofa::core::behavior::ConstraintSolver);
 SOFA_DECLARE_OPAQUE_FUNCTION_BETWEEN_BASE_AND(sofa::core::behavior::BaseLinearSolver);
-SOFA_DECLARE_OPAQUE_FUNCTION_BETWEEN_BASE_AND(sofa::core::behavior::BaseMechanicalState);
+SOFA_DECLARE_OPAQUE_FUNCTION_BETWEEN_BASE_AND(sofa::core::behavior::BaseVectorState);
 SOFA_DECLARE_OPAQUE_FUNCTION_BETWEEN_BASE_AND(sofa::core::behavior::BaseForceField);
 SOFA_DECLARE_OPAQUE_FUNCTION_BETWEEN_BASE_AND(sofa::core::behavior::BaseInteractionForceField);
 SOFA_DECLARE_OPAQUE_FUNCTION_BETWEEN_BASE_AND(sofa::core::behavior::BaseProjectiveConstraintSet);

diff --git a/Sofa/framework/Core/src/sofa/core/objectmodel/Base.h b/Sofa/framework/Core/src/sofa/core/objectmodel/Base.h
@@ -439,7 +439,7 @@ class SOFA_CORE_API Base : public IntrusiveObject
     SOFA_BASE_CAST_DEFINITION( behavior,    LinearSolver                           )
     SOFA_BASE_CAST_DEFINITION( behavior,    ConstraintSolver                       )
     SOFA_BASE_CAST_DEFINITION( behavior,    BaseMass                               )
-    SOFA_BASE_CAST_DEFINITION( behavior,    BaseMechanicalState                    )
+    SOFA_BASE_CAST_DEFINITION( behavior,    BaseVectorState                        )
     SOFA_BASE_CAST_DEFINITION( behavior,    BaseInteractionForceField              )
     SOFA_BASE_CAST_DEFINITION( behavior,    BaseInteractionConstraint              )
     SOFA_BASE_CAST_DEFINITION( behavior,    BaseForceField                         )
@@ -469,6 +469,9 @@ class SOFA_CORE_API Base : public IntrusiveObject
     SOFA_ATTRIBUTE_DEPRECATED__TOBASEOBJECT() virtual const objectmodel::BaseComponent* toBaseObject() const { return toBaseComponent(); }
     SOFA_ATTRIBUTE_DEPRECATED__TOBASEOBJECT() virtual       objectmodel::BaseComponent* toBaseObject()       { return toBaseComponent(); }
 
+    SOFA_ATTRIBUTE_DEPRECATED__TOBASEMECHANICALSTATE() virtual const behavior::BaseVectorState* toBaseMechanicalState() const { return toBaseVectorState(); }
+    SOFA_ATTRIBUTE_DEPRECATED__TOBASEMECHANICALSTATE() virtual       behavior::BaseVectorState* toBaseMechanicalState()       { return toBaseVectorState(); }
+
     /// @}
 };
 

diff --git a/Sofa/framework/Core/src/sofa/core/objectmodel/BaseNode.h b/Sofa/framework/Core/src/sofa/core/objectmodel/BaseNode.h
@@ -171,7 +171,7 @@ class SOFA_CORE_API BaseNode : public virtual Base
      BASENODE_ADD_SPECIAL_COMPONENT( core::topology::BaseMeshTopology, MeshTopology, meshTopology )
      BASENODE_ADD_SPECIAL_COMPONENT( core::topology::BaseTopologyObject, TopologyObject, topologyObject )
      BASENODE_ADD_SPECIAL_COMPONENT( core::BaseState, State, state )
-     BASENODE_ADD_SPECIAL_COMPONENT( core::behavior::BaseMechanicalState,MechanicalState, mechanicalState )
+     BASENODE_ADD_SPECIAL_COMPONENT( core::behavior::BaseVectorState,MechanicalState, mechanicalState )
      BASENODE_ADD_SPECIAL_COMPONENT( core::BaseMapping, MechanicalMapping, mechanicalMapping )
      BASENODE_ADD_SPECIAL_COMPONENT( core::behavior::BaseMass, Mass, mass )
      BASENODE_ADD_SPECIAL_COMPONENT( core::behavior::BaseForceField, ForceField, forceField )