Links

Methods

{
  "name": "TetrahedronCollisionModel",
  "namespace": "sofa::component::collision::geometry",
  "module": "Sofa.Component.Collision.Geometry",
  "include": "sofa/component/collision/geometry/TetrahedronCollisionModel.h",
  "doc": "Collision model using a tetrahedral mesh, as described in BaseMeshTopology.",
  "inherits": [
    "CollisionModel"
  ],
  "templates": [],
  "data_fields": [],
  "links": [
    {
      "name": "l_topology",
      "target": "BaseMeshTopology",
      "kind": "single",
      "xmlname": "topology",
      "help": "link to the topology container"
    }
  ],
  "methods": [
    {
      "name": "updateFromTopology",
      "return_type": "void",
      "params": [],
      "is_virtual": true,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "protected"
    },
    {
      "name": "addTetraToDraw",
      "return_type": "void",
      "params": [
        {
          "name": "t",
          "type": "const Tetrahedron &"
        },
        {
          "name": "tetraVertices",
          "type": "int &"
        },
        {
          "name": "normalVertices",
          "type": "int &"
        }
      ],
      "is_virtual": false,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "protected"
    },
    {
      "name": "drawCollisionModel",
      "return_type": "void",
      "params": [
        {
          "name": "vparams",
          "type": "const core::visual::VisualParams *"
        }
      ],
      "is_virtual": true,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "protected"
    },
    {
      "name": "init",
      "return_type": "void",
      "params": [],
      "is_virtual": true,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "public"
    },
    {
      "name": "resize",
      "return_type": "void",
      "params": [
        {
          "name": "size",
          "type": "int"
        }
      ],
      "is_virtual": false,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "public"
    },
    {
      "name": "computeBoundingTree",
      "return_type": "void",
      "params": [
        {
          "name": "maxDepth",
          "type": "int"
        }
      ],
      "is_virtual": true,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "public"
    },
    {
      "name": "draw",
      "return_type": "void",
      "params": [
        {
          "name": "",
          "type": "const core::visual::VisualParams *"
        },
        {
          "name": "index",
          "type": "int"
        }
      ],
      "is_virtual": false,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "public"
    },
    {
      "name": "getMechanicalState",
      "return_type": "core::behavior::MechanicalState<defaulttype::Vec3Types> *",
      "params": [],
      "is_virtual": false,
      "is_pure_virtual": false,
      "is_static": false,
      "access": "public"
    }
  ],
  "description": "The `TetrahedronCollisionModel` is a SOFA collision model that utilizes tetrahedral meshes to represent objects for collision detection. This model inherits from the base class `core::CollisionModel`, providing functionality specific to representing and handling collisions of tetrahedral elements. The component interacts with other components through its `l_topology` link, which must be connected to a `BaseMeshTopology` object to access mesh information such as vertices and connectivity.\n\nThe component supports initializing itself based on the topology provided by the linked `BaseMeshTopology`. It also updates its internal state whenever changes occur in the underlying topology. The component computes bounding trees for collision detection, allowing for efficient hierarchical representation of tetrahedral elements during simulations. Additionally, it provides methods to draw the tetrahedron mesh and handle drawing details such as normals.\n\nFor practical usage, this component should be used when simulating objects that require detailed tetrahedral mesh-based collision models. Ensure that a `BaseMeshTopology` is linked properly for the `TetrahedronCollisionModel` to function correctly.",
  "maths": "The `TetrahedronCollisionModel` is a component within the SOFA framework designed to handle collision detection for objects represented by tetrahedral meshes. This model does not directly contribute to the governing equations or operators such as mass matrix $M$, stiffness matrix $K$, internal force $f_{int}$, or residual $R$. Instead, its role focuses on defining and handling collisions between tetrahedral elements within a mesh topology.\n\n### Governing Equations and Operators\n- **Collision Model**: The component does not implement governing equations directly related to FEM. It is primarily used for collision detection and bounding volume hierarchy (BVH) construction rather than mechanics or deformation calculations.\n\n### Constitutive Laws\n- **No Constitutive Law**: This model does not involve any specific constitutive laws, strain measures, stress tensors, hyperelastic potentials, or damping models. Its purpose is to define the geometry of collision elements and efficiently detect collisions between them.\n\n### Role in FEM Pipeline\n- **Collision Detection**: The `TetrahedronCollisionModel` is used for collision detection within a tetrahedral mesh. It does not directly contribute to the assembly, time integration, nonlinear solve, or linear solve phases of the global FEM pipeline. Instead, it supports constraints and interactions between deformable bodies by providing accurate collision information.\n\n### Numerical Methods and Discretization Choices\n- **Bounding Tree Construction**: The component computes a bounding tree (BVH) for efficient collision detection. This involves computing the minimum and maximum coordinates of each tetrahedron to define bounding boxes or spheres that enclose them. These bounding volumes are used in hierarchical structures to quickly identify potential collisions without checking every pair of elements.\n\n- **Visualization**: The component supports drawing methods (`drawCollisionModel`, `draw`) for visualizing the tetrahedral mesh and its collision elements, including normals if specified by the display flags.\n\n### Variational / Lagrangian Mechanics Framework Fit\n- **Geometry Definition**: Although not directly involved in the variational or Lagrangian mechanics framework, the `TetrahedronCollisionModel` plays a crucial role in defining the geometry of deformable objects. The precise definition and handling of tetrahedral elements ensure that collision detection is accurate and efficient, which indirectly supports the overall simulation fidelity.\n\n- **Constraint Handling**: By providing accurate collision information, this model helps enforce constraints (such as non-penetration) between different parts of a deformable object or between multiple objects in contact. This constraint handling is an essential part of maintaining physical consistency during FEM simulations.\n\n### Summary\nThe `TetrahedronCollisionModel` is focused on providing accurate and efficient collision detection for tetrahedral meshes, which is critical for ensuring that interactions and constraints within the simulation are physically consistent. It does not contribute to the mechanics or deformation aspects of the FEM pipeline but supports them by defining the geometry and detecting collisions between deformable bodies.",
  "abstract": "The `TetrahedronCollisionModel` provides collision detection using tetrahedral meshes in SOFA simulations, supporting efficient bounding volume hierarchy (BVH) construction for accurate interaction handling.",
  "sheet": "# TetrahedronCollisionModel\n\n## Overview\nThe `TetrahedronCollisionModel` is a component within the SOFA framework designed to handle collision detection for objects represented by tetrahedral meshes. It inherits from the base class `core::CollisionModel`, providing functionality specific to representing and handling collisions of tetrahedral elements.\n\n## Parameters and Data\nThe significant data field exposed by this component is:\n- **l_topology**: A link to a `BaseMeshTopology` object, which provides access to mesh information such as vertices and connectivity. This link is essential for the collision model to function correctly.\n\n## Dependencies and Connections\nThis component requires a connection to a `BaseMeshTopology` object through its `l_topology` link to access the necessary mesh data for collision detection. It fits into the scene graph by providing accurate collision information, which supports constraints and interactions between deformable bodies in the simulation.\n\n## Practical Notes\nEnsure that a `BaseMeshTopology` is linked properly for the `TetrahedronCollisionModel` to function correctly. The component computes bounding trees (BVH) for efficient collision detection, so it is important to configure this appropriately for optimal performance."
}