Methods

{
  "name": "MechanicalResetConstraintVisitor",
  "namespace": "sofa::simulation::mechanicalvisitor",
  "module": "Sofa.framework.Simulation.Core",
  "include": "sofa/simulation/mechanicalvisitor/MechanicalResetConstraintVisitor.h",
  "doc": "",
  "inherits": [
    "BaseMechanicalVisitor"
  ],
  "templates": [],
  "data_fields": [],
  "links": [],
  "methods": [
    {
      "name": "fwdMechanicalState",
      "return_type": "Result",
      "params": [
        {
          "name": "",
          "type": "simulation::Node *"
        },
        {
          "name": "mm",
          "type": "sofa::core::behavior::BaseMechanicalState *"
        }
      ],
      "is_virtual": true,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "public"
    },
    {
      "name": "fwdMappedMechanicalState",
      "return_type": "Result",
      "params": [
        {
          "name": "",
          "type": "simulation::Node *"
        },
        {
          "name": "mm",
          "type": "sofa::core::behavior::BaseMechanicalState *"
        }
      ],
      "is_virtual": true,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "public"
    },
    {
      "name": "fwdConstraintSet",
      "return_type": "Result",
      "params": [
        {
          "name": "",
          "type": "simulation::Node *"
        },
        {
          "name": "mm",
          "type": "sofa::core::behavior::BaseConstraintSet *"
        }
      ],
      "is_virtual": true,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "public"
    },
    {
      "name": "stopAtMechanicalMapping",
      "return_type": "bool",
      "params": [
        {
          "name": "",
          "type": "simulation::Node *"
        },
        {
          "name": "",
          "type": "sofa::core::BaseMapping *"
        }
      ],
      "is_virtual": true,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "public"
    },
    {
      "name": "isThreadSafe",
      "return_type": "bool",
      "params": [],
      "is_virtual": true,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "public"
    }
  ],
  "description": "The `MechanicalResetConstraintVisitor` is a component in the SOFA framework, specifically within the `sofa::simulation::mechanicalvisitor` namespace. It inherits from `BaseMechanicalVisitor`, indicating its role as a visitor for mechanical states and constraints during simulation steps. This visitor resets constraint forces or conditions in the simulation, contributing to maintaining correct physical state updates across different components.\n\n### Interactions with Other Components\n- **fwdMechanicalState**: Resets the constraint for the provided `BaseMechanicalState` object, ensuring that it remains consistent throughout the simulation loop.\n- **fwdMappedMechanicalState**: Similar to `fwdMechanicalState`, this method also resets constraints but is applied specifically to mapped mechanical states, allowing for coordinated updates across different parts of a multi-model system.\n- **fwdConstraintSet**: Resets constraint sets, ensuring that any defined constraints are properly initialized or reset during the simulation process.\n\n### Practical Usage Guidance\nThis visitor is used internally within SOFA's simulation pipeline. It ensures that mechanical states and constraints are correctly updated between different simulation steps, particularly when dealing with interactions across multiple components or mappings. Users typically do not interact directly with this component but rely on it as part of the framework’s underlying mechanics for accurate simulations.",
  "maths": "The `MechanicalResetConstraintVisitor` in the SOFA framework is responsible for resetting constraints during the simulation process, ensuring that mechanical states and constraint forces are correctly initialized or updated between different simulation steps. This visitor operates on mechanical states and constraint sets to maintain consistency within the overall simulation.\n\n### Governing Equations / Operators:\n- **Constraint Force Reset**: The `MechanicalResetConstraintVisitor` does not directly contribute to the governing equations such as mass matrix $M$, stiffness matrix $K$, internal force $f_{int}$, or residual $R$. Instead, it ensures that constraint forces and conditions are correctly reset.\n\n### Constitutive / Kinematic Laws:\n- **Constraints**: The visitor handles constraints represented by their respective sets. Constraints can involve holonomic (position) or non-holonomic (velocity) restrictions on the motion of mechanical states. These constraints are typically enforced through Lagrange multipliers and are expressed as:\n  \n  \\[\n  J(x) = \begin{bmatrix} M & J^T \\\\ J & 0 \\end{bmatrix}\n  \\]\n\n### Role in the Global FEM Pipeline:\n- **Assembly Phase**: During assembly, the visitor ensures that constraint forces are correctly initialized or reset for each mechanical state.\n- **Nonlinear Solve / Constraint Handling**: The visitor contributes to maintaining consistency by resetting constraints before nonlinear solution steps. This includes ensuring that any defined constraints are properly initialized or reset during the simulation process.\n\n### Numerical Methods and Discretization Choices:\n- The `MechanicalResetConstraintVisitor` does not directly encode specific numerical methods or discretization choices but relies on the framework's overall handling of these aspects.\n\n### Fit into Variational / Lagrangian Mechanics Framework:\n- **Variational Consistency**: Although it does not directly implement variational formulations, the visitor ensures that constraints are correctly managed within a variational and Lagrangian mechanics context. This includes ensuring that constraint forces are appropriately reset to maintain consistency with the underlying physics.\n\n### Methods Summary:\n- `fwdMechanicalState`: Resets the constraint for the provided `BaseMechanicalState` object, ensuring correct initialization or resetting of constraints in mechanical states.\n- `fwdMappedMechanicalState`: Similar to `fwdMechanicalState`, but specifically for mapped mechanical states, allowing coordinated updates across different parts of a multi-model system.\n- `fwdConstraintSet`: Resets constraint sets, ensuring that any defined constraints are properly initialized or reset during the simulation process.\n\n### Key Conceptual Insight:\nThis component plays a critical role in maintaining consistent and accurate simulations by resetting constraints to ensure that mechanical states remain physically valid throughout the simulation loop.",
  "abstract": "Resets constraints for mechanical states during simulation steps to maintain consistent physical state updates.",
  "sheet": "# MechanicalResetConstraintVisitor\n\n## Overview\nThe `MechanicalResetConstraintVisitor` is a visitor component that resets constraints in the SOFA framework, ensuring consistency across different mechanical states and constraint sets. It inherits from `BaseMechanicalVisitor`, indicating its role as part of the simulation pipeline for maintaining correct physical state updates.\n\n## Dependencies and Connections\nThis component typically interacts with other components such as `BaseMechanicalState` and `BaseConstraintSet`. It ensures that constraints are correctly reset during the simulation process, contributing to accurate simulations by maintaining consistency across different mechanical states."
}