BaseNode
The `BaseNode` class in the SOFA framework is central to defining the hierarchical scene data structure for simulations. Each node represents an element within the simulation and can have parent and child nodes, forming a tree-like structure. Nodes can also contain various objects that represent different aspects of the simulation, such as mechanical models, constraints, solvers, and visual components. `BaseNode` interacts with other SOFA components through several methods, allowing for hierarchical management (e.g., adding/removing children), attaching/detaching objects, managing context, and accessing specific algorithms like animation loops or collision pipelines. It provides a generic interface to manage these interactions without specifying concrete implementations, leaving that to derived classes. Practical usage of `BaseNode` involves constructing the scene graph by creating nodes, adding hierarchical relationships between them, and attaching simulation components such as solvers, visual models, and force fields. The component ensures consistency in context management across the attached objects, making it a foundational element for building complex simulations.
- abstract
- `BaseNode` defines the hierarchical structure of a SOFA simulation by managing parent-child relationships and attaching objects such as solvers, force fields, and visual models to nodes.
- sheet
- # BaseNode ## Overview The `BaseNode` class is central to defining the hierarchical scene data structure in SOFA simulations. It manages parent-child relationships between nodes and attaches various simulation components like mechanical models, constraints, solvers, and visual elements. ## Dependencies and Connections Each node can have parent and child nodes, forming a tree-like hierarchy. `BaseNode` interacts with other SOFA components to manage objects within the scene graph, including adding/removing children, attaching/detaching simulation components, managing context, and accessing specific algorithms like animation loops or collision pipelines.
- description
- The `BaseNode` class in the SOFA framework is central to defining the hierarchical scene data structure for simulations. Each node represents an element within the simulation and can have parent and child nodes, forming a tree-like structure. Nodes can also contain various objects that represent different aspects of the simulation, such as mechanical models, constraints, solvers, and visual components. `BaseNode` interacts with other SOFA components through several methods, allowing for hierarchical management (e.g., adding/removing children), attaching/detaching objects, managing context, and accessing specific algorithms like animation loops or collision pipelines. It provides a generic interface to manage these interactions without specifying concrete implementations, leaving that to derived classes. Practical usage of `BaseNode` involves constructing the scene graph by creating nodes, adding hierarchical relationships between them, and attaching simulation components such as solvers, visual models, and force fields. The component ensures consistency in context management across the attached objects, making it a foundational element for building complex simulations.
- maths
- The `BaseNode` class in the SOFA framework is central to defining a hierarchical scene data structure for simulations. Each node represents an element within the simulation and can have parent and child nodes, forming a tree-like structure. This structure facilitates the organization of complex simulations into manageable parts. Here are some mathematical and physical descriptions of this component: ### Hierarchical Structure - **Node Relationships:** The hierarchical relationship between `BaseNode` objects is represented by a directed graph where each node can have one or more parent nodes (multinode support) and zero or more child nodes. - \( G = (V, E) \), where \( V \) represents the set of nodes and \( E \) represents the set of edges that connect parent-child relationships. Each edge is directed from a parent node to its children. - **Traversal:** Traversals are essential for operations like scene graph traversal or state propagation. Pre-order, post-order, in-order traversals can be performed depending on whether you need to process parents first (pre-order) or children first (post-order). - For instance, a pre-order traversal ensures that each node is processed before its children. ### Context Management and Consistency - **Context:** Each `BaseNode` has an associated context (`BaseContext`) which holds information relevant to all objects within the node. This can include global state variables, shared data structures, or configuration settings. The consistency of this context across nodes and their attached objects ensures coherent behavior in the simulation. - Context consistency is maintained by methods like `setObjectContext` and `clearObjectContext`, ensuring that every object within a node has access to its appropriate context. ### Object Management - **Adding/Removing Objects:** Methods such as `addObject` and `removeObject` manage objects attached to each node. These objects can represent various physical entities, including mechanical models (e.g., mass, force fields), constraints, solvers, visual components, etc. - \( O_i \) represents an object of type \( T \). The operation `addObject(O_i)` adds the object to a sequence within the node and updates its context. Similarly, `removeObject(O_i)` removes it from the sequence and clears its context. ### Specific Components Management - **Special Components:** There are specific methods for managing particular types of components (e.g., `BaseBehaviorModel`, `OdeSolver`, `ForceField`). Each method ensures that a component is added to or removed from a dedicated sequence within the node, maintaining their order and ensuring proper execution during simulation. - \( S_{behavior} \) represents the sequence for behavior models. The operation `addBehaviorModel(B_i)` adds behavior model \( B_i \) to \( S_{behavior} \). ### Physical Interactions and Algorithms - **Physics Engine Integration:** SOFA integrates physical simulation components through methods like `getOdeSolver`, `getCollisionPipeline`, etc., which return pointers to the corresponding solver or pipeline used in the node. These solvers handle physical computations, such as solving systems of equations for mechanics. - \( S_{ode} \) represents an ODE solver object. The operation `getOdeSolver()` returns a pointer to \( S_{ode} \), ensuring that it can be utilized by other components within the node or its subnodes. ### Scene Graph Navigation and Path Resolution - **Path Navigation:** Methods like `getPathName` and `getRootPath` allow for navigation through the scene graph and resolution of paths between nodes, facilitating operations such as linking objects across different parts of the simulation. - The path from a node to its root can be represented by a string that encodes the sequence of parent-child relationships: \( P_{root} = (N_1 \rightarrow N_2 \rightarrow ... \rightarrow N_n) \). ### Conclusion The `BaseNode` class provides a robust framework for organizing and managing simulation components in SOFA. It enables hierarchical scene construction, context management, consistent object attachment/detachment, and integration with specific physical solvers and algorithms, thereby ensuring efficient and coherent simulations.
{
"name": "BaseNode",
"main": {
"name": "BaseNode",
"namespace": "sofa::core::objectmodel",
"module": "Sofa.framework.Core",
"include": "sofa/core/objectmodel/BaseNode.h",
"doc": "Base class for simulation nodes.\n A Node is a class defining the main scene data structure of a simulation.\n It defined hierarchical relations between elements.\n Each node can have parent and child nodes (potentially defining a tree),\n as well as attached objects (the leaves of the tree).\n\\author Jeremie Allard",
"inherits": [
"Base"
],
"templates": [],
"data_fields": [],
"links": [],
"methods": [
{
"name": "toBaseNode",
"return_type": "const BaseNode *",
"params": [],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "getChildren",
"return_type": "Children",
"params": [],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "getParents",
"return_type": "Parents",
"params": [],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "getNbParents",
"return_type": "int",
"params": [],
"is_virtual": false,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "getFirstParent",
"return_type": "BaseNode *",
"params": [],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "getRoot",
"return_type": "BaseNode *",
"params": [],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addChild",
"return_type": "void",
"params": [
{
"name": "node",
"type": "int"
}
],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "removeChild",
"return_type": "void",
"params": [
{
"name": "node",
"type": "int"
}
],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "moveChild",
"return_type": "void",
"params": [
{
"name": "node",
"type": "int"
},
{
"name": "prev_parent",
"type": "int"
}
],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "moveChild",
"return_type": "void",
"params": [
{
"name": "node",
"type": "int"
}
],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "addObject",
"return_type": "bool",
"params": [
{
"name": "obj",
"type": "int"
},
{
"name": "",
"type": "TypeOfInsertion"
}
],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "removeObject",
"return_type": "bool",
"params": [
{
"name": "obj",
"type": "int"
}
],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "moveObject",
"return_type": "void",
"params": [
{
"name": "obj",
"type": "int"
}
],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "hasParent",
"return_type": "bool",
"params": [
{
"name": "node",
"type": "const BaseNode *"
}
],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "hasAncestor",
"return_type": "bool",
"params": [
{
"name": "node",
"type": "const BaseNode *"
}
],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "detachFromGraph",
"return_type": "void",
"params": [],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "getContext",
"return_type": "BaseContext *",
"params": [],
"is_virtual": true,
"is_pure_virtual": true,
"is_static": false,
"access": "public"
},
{
"name": "getPathName",
"return_type": "int",
"params": [],
"is_virtual": false,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "getRootPath",
"return_type": "int",
"params": [],
"is_virtual": false,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "findLinkDestClass",
"return_type": "Base *",
"params": [
{
"name": "destType",
"type": "const BaseClass *"
},
{
"name": "path",
"type": "const int &"
},
{
"name": "link",
"type": "const BaseLink *"
}
],
"is_virtual": false,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "getAnimationLoop",
"return_type": "core::behavior::BaseAnimationLoop *",
"params": [],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "getOdeSolver",
"return_type": "core::behavior::OdeSolver *",
"params": [],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "getCollisionPipeline",
"return_type": "core::collision::Pipeline *",
"params": [],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "getVisualLoop",
"return_type": "core::visual::VisualLoop *",
"params": [],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "setObjectContext",
"return_type": "void",
"params": [
{
"name": "obj",
"type": "int"
}
],
"is_virtual": false,
"is_pure_virtual": false,
"is_static": false,
"access": "protected"
},
{
"name": "clearObjectContext",
"return_type": "void",
"params": [
{
"name": "obj",
"type": "int"
}
],
"is_virtual": false,
"is_pure_virtual": false,
"is_static": false,
"access": "protected"
},
{
"name": "addAnimationLoop",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseAnimationLoop *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeAnimationLoop",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseAnimationLoop *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addVisualLoop",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::visual::VisualLoop *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeVisualLoop",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::visual::VisualLoop *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addBehaviorModel",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::BehaviorModel *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeBehaviorModel",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::BehaviorModel *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addMapping",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::BaseMapping *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeMapping",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::BaseMapping *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addOdeSolver",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::OdeSolver *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeOdeSolver",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::OdeSolver *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addConstraintSolver",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::ConstraintSolver *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeConstraintSolver",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::ConstraintSolver *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addLinearSolver",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseLinearSolver *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeLinearSolver",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseLinearSolver *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addTopology",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::topology::Topology *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeTopology",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::topology::Topology *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addMeshTopology",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::topology::BaseMeshTopology *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeMeshTopology",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::topology::BaseMeshTopology *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addTopologyObject",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::topology::BaseTopologyObject *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeTopologyObject",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::topology::BaseTopologyObject *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addState",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::BaseState *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeState",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::BaseState *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addMechanicalState",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseMechanicalState *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeMechanicalState",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseMechanicalState *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addMechanicalMapping",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::BaseMapping *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeMechanicalMapping",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::BaseMapping *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addMass",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseMass *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeMass",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseMass *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addForceField",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseForceField *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeForceField",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseForceField *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addInteractionForceField",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseInteractionForceField *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeInteractionForceField",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseInteractionForceField *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addProjectiveConstraintSet",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseProjectiveConstraintSet *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeProjectiveConstraintSet",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseProjectiveConstraintSet *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addConstraintSet",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseConstraintSet *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeConstraintSet",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::behavior::BaseConstraintSet *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addContextObject",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::objectmodel::ContextObject *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeContextObject",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::objectmodel::ContextObject *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addConfigurationSetting",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::objectmodel::ConfigurationSetting *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeConfigurationSetting",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::objectmodel::ConfigurationSetting *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addShader",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::visual::Shader *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeShader",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::visual::Shader *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addVisualModel",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::visual::VisualModel *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeVisualModel",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::visual::VisualModel *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addVisualStyle",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::visual::BaseVisualStyle *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeVisualStyle",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::visual::BaseVisualStyle *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addVisualManager",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::visual::VisualManager *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeVisualManager",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::visual::VisualManager *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addCollisionModel",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::CollisionModel *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeCollisionModel",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::CollisionModel *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "addCollisionPipeline",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::collision::Pipeline *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
},
{
"name": "removeCollisionPipeline",
"return_type": "void",
"params": [
{
"name": "",
"type": "core::collision::Pipeline *"
}
],
"is_virtual": true,
"is_pure_virtual": false,
"is_static": false,
"access": "public"
}
]
},
"desc": {
"description": "The `BaseNode` class in the SOFA framework is central to defining the hierarchical scene data structure for simulations. Each node represents an element within the simulation and can have parent and child nodes, forming a tree-like structure. Nodes can also contain various objects that represent different aspects of the simulation, such as mechanical models, constraints, solvers, and visual components.\n\n`BaseNode` interacts with other SOFA components through several methods, allowing for hierarchical management (e.g., adding/removing children), attaching/detaching objects, managing context, and accessing specific algorithms like animation loops or collision pipelines. It provides a generic interface to manage these interactions without specifying concrete implementations, leaving that to derived classes.\n\nPractical usage of `BaseNode` involves constructing the scene graph by creating nodes, adding hierarchical relationships between them, and attaching simulation components such as solvers, visual models, and force fields. The component ensures consistency in context management across the attached objects, making it a foundational element for building complex simulations."
},
"maths": {
"maths": "The `BaseNode` class in the SOFA framework is central to defining a hierarchical scene data structure for simulations. Each node represents an element within the simulation and can have parent and child nodes, forming a tree-like structure. This structure facilitates the organization of complex simulations into manageable parts. Here are some mathematical and physical descriptions of this component:\n\n### Hierarchical Structure\n- **Node Relationships:** The hierarchical relationship between `BaseNode` objects is represented by a directed graph where each node can have one or more parent nodes (multinode support) and zero or more child nodes.\n - \\( G = (V, E) \\), where \\( V \\) represents the set of nodes and \\( E \\) represents the set of edges that connect parent-child relationships. Each edge is directed from a parent node to its children.\n- **Traversal:** Traversals are essential for operations like scene graph traversal or state propagation. Pre-order, post-order, in-order traversals can be performed depending on whether you need to process parents first (pre-order) or children first (post-order).\n - For instance, a pre-order traversal ensures that each node is processed before its children.\n\n### Context Management and Consistency\n- **Context:** Each `BaseNode` has an associated context (`BaseContext`) which holds information relevant to all objects within the node. This can include global state variables, shared data structures, or configuration settings. The consistency of this context across nodes and their attached objects ensures coherent behavior in the simulation.\n - Context consistency is maintained by methods like `setObjectContext` and `clearObjectContext`, ensuring that every object within a node has access to its appropriate context.\n\n### Object Management\n- **Adding/Removing Objects:** Methods such as `addObject` and `removeObject` manage objects attached to each node. These objects can represent various physical entities, including mechanical models (e.g., mass, force fields), constraints, solvers, visual components, etc.\n - \\( O_i \\) represents an object of type \\( T \\). The operation `addObject(O_i)` adds the object to a sequence within the node and updates its context. Similarly, `removeObject(O_i)` removes it from the sequence and clears its context.\n\n### Specific Components Management\n- **Special Components:** There are specific methods for managing particular types of components (e.g., `BaseBehaviorModel`, `OdeSolver`, `ForceField`). Each method ensures that a component is added to or removed from a dedicated sequence within the node, maintaining their order and ensuring proper execution during simulation.\n - \\( S_{behavior} \\) represents the sequence for behavior models. The operation `addBehaviorModel(B_i)` adds behavior model \\( B_i \\) to \\( S_{behavior} \\).\n\n### Physical Interactions and Algorithms\n- **Physics Engine Integration:** SOFA integrates physical simulation components through methods like `getOdeSolver`, `getCollisionPipeline`, etc., which return pointers to the corresponding solver or pipeline used in the node. These solvers handle physical computations, such as solving systems of equations for mechanics.\n - \\( S_{ode} \\) represents an ODE solver object. The operation `getOdeSolver()` returns a pointer to \\( S_{ode} \\), ensuring that it can be utilized by other components within the node or its subnodes.\n\n### Scene Graph Navigation and Path Resolution\n- **Path Navigation:** Methods like `getPathName` and `getRootPath` allow for navigation through the scene graph and resolution of paths between nodes, facilitating operations such as linking objects across different parts of the simulation.\n - The path from a node to its root can be represented by a string that encodes the sequence of parent-child relationships: \\( P_{root} = (N_1 \\rightarrow N_2 \\rightarrow ... \\rightarrow N_n) \\).\n\n### Conclusion\nThe `BaseNode` class provides a robust framework for organizing and managing simulation components in SOFA. It enables hierarchical scene construction, context management, consistent object attachment/detachment, and integration with specific physical solvers and algorithms, thereby ensuring efficient and coherent simulations."
},
"summary": {
"abstract": "`BaseNode` defines the hierarchical structure of a SOFA simulation by managing parent-child relationships and attaching objects such as solvers, force fields, and visual models to nodes.",
"sheet": "# BaseNode\n\n## Overview\nThe `BaseNode` class is central to defining the hierarchical scene data structure in SOFA simulations. It manages parent-child relationships between nodes and attaches various simulation components like mechanical models, constraints, solvers, and visual elements.\n\n## Dependencies and Connections\nEach node can have parent and child nodes, forming a tree-like hierarchy. `BaseNode` interacts with other SOFA components to manage objects within the scene graph, including adding/removing children, attaching/detaching simulation components, managing context, and accessing specific algorithms like animation loops or collision pipelines."
}
}