Drake
SceneGraph< T > Class Template Reference

SceneGraph serves as the nexus for all geometry (and geometry-based operations) in a Diagram. More...

#include <drake/geometry/geometry_state.h>

Inheritance diagram for SceneGraph< T >:
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Collaboration diagram for SceneGraph< T >:
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Public Member Functions

 SceneGraph ()
 
template<typename U >
 SceneGraph (const SceneGraph< U > &other)
 Constructor used for scalar conversions. More...
 
 ~SceneGraph () override
 
Does not allow copy, move, or assignment
 SceneGraph (const SceneGraph &)=delete
 
SceneGraphoperator= (const SceneGraph &)=delete
 
 SceneGraph (SceneGraph &&)=delete
 
SceneGraphoperator= (SceneGraph &&)=delete
 
Port management

Access to SceneGraph's input/output ports.

This topic includes registration of geometry sources because the input ports are mapped to registered geometry sources.

A source that registers frames and geometries must connect outputs to the inputs associated with that source. Failure to do so will be treated as a runtime error during the evaluation of SceneGraph. SceneGraph will detect that frames have been registered but no values have been provided.

SourceId RegisterSource (const std::string &name="")
 Registers a new source to the geometry system. More...
 
bool SourceIsRegistered (SourceId id) const
 Reports if the given source id is registered. More...
 
const systems::InputPort< T > & get_source_pose_port (SourceId id)
 Given a valid source id, returns a pose input port associated with that id. More...
 
const systems::OutputPort< T > & get_pose_bundle_output_port () const
 Returns the output port which produces the PoseBundle for LCM communication to drake visualizer. More...
 
const systems::OutputPort< T > & get_query_output_port () const
 Returns the output port which produces the QueryObject for performing geometric queries. More...
 
Topology Manipulation

Topology manipulation consists of changing the data contained in the world.

This includes registering a new geometry source, adding or removing frames, and adding or removing geometries.

Currently, the topology can only be manipulated during initialization. Eventually, the API will expand to include modifications of the topology during discrete updates.

The initialization phase begins with the instantiation of a SceneGraph and ends when a context is allocated by the SceneGraph instance. This is the only phase when geometry sources can be registered with SceneGraph. Once a source is registered, it can register frames and geometries. Any frames and geometries registered during this phase become part of the default context state for SceneGraph and calls to CreateDefaultContext() will produce identical contexts.

Every geometry must ultimately be associated with a parent frame. The position of every geometry in the world depends on a hierarchy of frames between it and the world. The pose of a geometry is described relative to its parent (a frame or another geometry). That parent may, in turn, also have a parent. So, the position of a particular geometry in the world frame depends on all of its ancestors which lie between it and the world frame. The act of assigning a frame or geometry as a child to another frame or geometry (as appropriate) and defining its pose, is referred to colloquially has "hanging" it on the parent.

Geometry sources can only hang frames or geometries onto other frames and/or geometries that it "owns".

FrameId RegisterFrame (SourceId source_id, const GeometryFrame &frame)
 Registers a new frame F on for this source. More...
 
FrameId RegisterFrame (SourceId source_id, FrameId parent_id, const GeometryFrame &frame)
 Registers a new frame F for this source. More...
 
GeometryId RegisterGeometry (SourceId source_id, FrameId frame_id, std::unique_ptr< GeometryInstance > geometry)
 Registers a new geometry G for this source. More...
 
GeometryId RegisterGeometry (SourceId source_id, GeometryId geometry_id, std::unique_ptr< GeometryInstance > geometry)
 Registers a new geometry G for this source. More...
 
GeometryId RegisterAnchoredGeometry (SourceId source_id, std::unique_ptr< GeometryInstance > geometry)
 Registers a new anchored geometry G for this source. More...
 
Collision filtering

The interface for limiting the scope of penetration queries (i.e., "filtering collisions").

The scene graph consists of the set of geometry G = D ⋃ A = {g₀, g₁, ..., gₙ}, where D is the set of dynamic geometry and A is the set of anchored geometry (by definition D ⋂ A = ∅). Collision occurs between pairs of geometries (e.g., (gᵢ, gⱼ)). The set of collision candidate pairs is initially defined as C = (G × G) - (A × A) - F - I, where:

  • G × G = {(gᵢ, gⱼ)}, ∀ gᵢ, gⱼ ∈ G is the cartesian product of the set of SceneGraph geometries.
  • A × A represents all pairs consisting only of anchored geometry; anchored geometry is never tested against other anchored geometry.
  • F = (gᵢ, gⱼ), such that frame(gᵢ) == frame(gⱼ); the pair where both geometries are rigidly affixed to the same frame. By implication, gᵢ, gⱼ ∈ D as only dynamic geometries are affixed to frames.
  • I = {(g, g)}, ∀ g ∈ G is the set of all pairs consisting of a geometry with itself; there is no collision between a geometry and itself.

Only pairs contained in C will be tested as part of penetration queries. These filter methods essentially create new sets of pairs and then subtract them from the candidate set C. See each method for details.

Modifications to C must be performed before context allocation.

void ExcludeCollisionsWithin (const GeometrySet &set)
 Excludes geometry pairs from collision evaluation by updating the candidate pair set C = C - P, where P = {(gᵢ, gⱼ)}, ∀ gᵢ, gⱼ ∈ G and G = {g₀, g₁, ..., gₘ} is the input set of geometries. More...
 
void ExcludeCollisionsBetween (const GeometrySet &setA, const GeometrySet &setB)
 Excludes geometry pairs from collision evaluation by updating the candidate pair set C = C - P, where P = {(a, b)}, ∀ a ∈ A, b ∈ B and A = {a₀, a₁, ..., aₘ} and B = {b₀, b₁, ..., bₙ} are the input sets of geometries setA and setB, respectively. More...
 
- Public Member Functions inherited from LeafSystem< T >
 ~LeafSystem () override
 
std::unique_ptr< CompositeEventCollection< T > > AllocateCompositeEventCollection () const final
 Allocates a CompositeEventCollection object for this system. More...
 
std::unique_ptr< LeafContext< T > > AllocateContext () const
 Shadows System<T>::AllocateContext to provide a more concrete return type LeafContext<T>. More...
 
std::unique_ptr< ContextBaseDoAllocateContext () const final
 Derived class implementations should allocate a suitable concrete Context type, then invoke the above InitializeContextBase() method. More...
 
void SetDefaultState (const Context< T > &context, State< T > *state) const override
 Default implementation: sets all continuous state to the model vector given in DeclareContinuousState (or zero if no model vector was given) and discrete states to zero. More...
 
void SetDefaultParameters (const Context< T > &context, Parameters< T > *parameters) const override
 Default implementation: sets all numeric parameters to the model vector given to DeclareNumericParameter, or else if no model was provided sets the numeric parameter to one. More...
 
std::unique_ptr< ContinuousState< T > > AllocateTimeDerivatives () const override
 Returns the AllocateContinuousState value, which must not be nullptr. More...
 
std::unique_ptr< DiscreteValues< T > > AllocateDiscreteVariables () const override
 Returns the AllocateDiscreteState value, which must not be nullptr. More...
 
std::multimap< int, intGetDirectFeedthroughs () const final
 Reports all direct feedthroughs from input ports to output ports. More...
 
 LeafSystem (const LeafSystem &)=delete
 
LeafSystemoperator= (const LeafSystem &)=delete
 
 LeafSystem (LeafSystem &&)=delete
 
LeafSystemoperator= (LeafSystem &&)=delete
 
- Public Member Functions inherited from System< T >
 ~System () override=default
 
void GetWitnessFunctions (const Context< T > &context, std::vector< const WitnessFunction< T > * > *w) const
 Gets the witness functions active for the given state. More...
 
CalcWitnessValue (const Context< T > &context, const WitnessFunction< T > &witness_func) const
 Evaluates a witness function at the given context. More...
 
 System (const System &)=delete
 
Systemoperator= (const System &)=delete
 
 System (System &&)=delete
 
Systemoperator= (System &&)=delete
 
std::unique_ptr< Context< T > > AllocateContext () const
 Returns a Context<T> suitable for use with this System<T>. More...
 
std::unique_ptr< BasicVector< T > > AllocateInputVector (const InputPort< T > &descriptor) const
 Given a port descriptor, allocates the vector storage. More...
 
std::unique_ptr< AbstractValueAllocateInputAbstract (const InputPort< T > &descriptor) const
 Given a port descriptor, allocates the abstract storage. More...
 
std::unique_ptr< SystemOutput< T > > AllocateOutput () const
 Returns a container that can hold the values of all of this System's output ports. More...
 
std::unique_ptr< Context< T > > CreateDefaultContext () const
 This convenience method allocates a context using AllocateContext() and sets its default values using SetDefaultContext(). More...
 
void SetDefaultContext (Context< T > *context) const
 
virtual void SetRandomState (const Context< T > &context, State< T > *state, RandomGenerator *generator) const
 Assigns random values to all elements of the state. More...
 
virtual void SetRandomParameters (const Context< T > &context, Parameters< T > *parameters, RandomGenerator *generator) const
 Assigns random values to all parameters. More...
 
void SetRandomContext (Context< T > *context, RandomGenerator *generator) const
 
void AllocateFixedInputs (Context< T > *context) const
 For each input port, allocates a fixed input of the concrete type that this System requires, and binds it to the port, disconnecting any prior input. More...
 
bool HasAnyDirectFeedthrough () const
 Returns true if any of the inputs to the system might be directly fed through to any of its outputs and false otherwise. More...
 
bool HasDirectFeedthrough (int output_port) const
 Returns true if there might be direct-feedthrough from any input port to the given output_port, and false otherwise. More...
 
bool HasDirectFeedthrough (int input_port, int output_port) const
 Returns true if there might be direct-feedthrough from the given input_port to the given output_port, and false otherwise. More...
 
void Publish (const Context< T > &context, const EventCollection< PublishEvent< T >> &events) const
 This method is the public entry point for dispatching all publish event handlers. More...
 
void Publish (const Context< T > &context) const
 Forces a publish on the system, given a context. More...
 
const T & EvalConservativePower (const Context< T > &context) const
 Returns a reference to the cached value of the conservative power. More...
 
const T & EvalNonConservativePower (const Context< T > &context) const
 Returns a reference to the cached value of the non-conservative power. More...
 
template<template< typename > class Vec = BasicVector>
const Vec< T > * EvalVectorInput (const Context< T > &context, int port_index) const
 Returns the value of the vector-valued input port with the given port_index as a BasicVector or a specific subclass Vec derived from BasicVector. More...
 
Eigen::VectorBlock< const VectorX< T > > EvalEigenVectorInput (const Context< T > &context, int port_index) const
 Returns the value of the vector-valued input port with the given port_index as an Eigen vector. More...
 
int get_num_constraint_equations (const Context< T > &context) const
 Gets the number of constraint equations for this system using the given context (useful in case the number of constraints is dependent upon the current state (as might be the case with a system modeled using piecewise differential algebraic equations). More...
 
Eigen::VectorXd EvalConstraintEquations (const Context< T > &context) const
 Evaluates the constraint equations for the system at the generalized coordinates and generalized velocity specified by the context. More...
 
Eigen::VectorXd EvalConstraintEquationsDot (const Context< T > &context) const
 Computes the time derivative of each constraint equation, evaluated at the generalized coordinates and generalized velocity specified by the context. More...
 
Eigen::VectorXd CalcVelocityChangeFromConstraintImpulses (const Context< T > &context, const Eigen::MatrixXd &J, const Eigen::VectorXd &lambda) const
 Computes the change in velocity from applying the given constraint forces to the system at the given context. More...
 
double CalcConstraintErrorNorm (const Context< T > &context, const Eigen::VectorXd &error) const
 Computes the norm on constraint error (used as a metric for comparing errors between the outputs of algebraic equations applied to two different state variable instances). More...
 
void CalcTimeDerivatives (const Context< T > &context, ContinuousState< T > *derivatives) const
 Calculates the time derivatives xcdot of the continuous state xc. More...
 
void CalcDiscreteVariableUpdates (const Context< T > &context, const EventCollection< DiscreteUpdateEvent< T >> &events, DiscreteValues< T > *discrete_state) const
 This method is the public entry point for dispatching all discrete variable update event handlers. More...
 
void CalcDiscreteVariableUpdates (const Context< T > &context, DiscreteValues< T > *discrete_state) const
 This method forces a discrete update on the system given a context, and the updated discrete state is stored in discrete_state. More...
 
void CalcUnrestrictedUpdate (const Context< T > &context, const EventCollection< UnrestrictedUpdateEvent< T >> &events, State< T > *state) const
 This method is the public entry point for dispatching all unrestricted update event handlers. More...
 
void CalcUnrestrictedUpdate (const Context< T > &context, State< T > *state) const
 This method forces an unrestricted update on the system given a context, and the updated state is stored in state. More...
 
CalcNextUpdateTime (const Context< T > &context, CompositeEventCollection< T > *events) const
 This method is called by a Simulator during its calculation of the size of the next continuous step to attempt. More...
 
void GetPerStepEvents (const Context< T > &context, CompositeEventCollection< T > *events) const
 This method is called by Simulator::Initialize() to gather all update and publish events that are to be handled in StepTo() at the point before Simulator integrates continuous state. More...
 
void GetInitializationEvents (const Context< T > &context, CompositeEventCollection< T > *events) const
 This method is called by Simulator::Initialize() to gather all update and publish events that need to be handled at initialization before the simulator starts integration. More...
 
optional< PeriodicEventDataGetUniquePeriodicDiscreteUpdateAttribute () const
 Gets whether there exists a unique periodic attribute that triggers one or more discrete update events (and, if so, returns that unique periodic attribute). More...
 
std::map< PeriodicEventData, std::vector< const Event< T > * >, PeriodicEventDataComparatorGetPeriodicEvents () const
 Gets all periodic triggered events for a system. More...
 
void CalcOutput (const Context< T > &context, SystemOutput< T > *outputs) const
 Utility method that computes for every output port i the value y(i) that should result from the current contents of the given Context. More...
 
CalcPotentialEnergy (const Context< T > &context) const
 Calculates and returns the potential energy current stored in the configuration provided in context. More...
 
CalcKineticEnergy (const Context< T > &context) const
 Calculates and returns the kinetic energy currently present in the motion provided in the given Context. More...
 
CalcConservativePower (const Context< T > &context) const
 Calculates and returns the rate at which mechanical energy is being converted from potential energy to kinetic energy by this system in the given Context. More...
 
CalcNonConservativePower (const Context< T > &context) const
 Calculates and returns the rate at which mechanical energy is being generated (positive) or dissipated (negative) other than by conversion between potential and kinetic energy (in the given Context). More...
 
void MapVelocityToQDot (const Context< T > &context, const VectorBase< T > &generalized_velocity, VectorBase< T > *qdot) const
 Transforms a given generalized velocity v to the time derivative qdot of the generalized configuration q taken from the supplied Context. More...
 
void MapVelocityToQDot (const Context< T > &context, const Eigen::Ref< const VectorX< T >> &generalized_velocity, VectorBase< T > *qdot) const
 Transforms the given generalized velocity to the time derivative of generalized configuration. More...
 
void MapQDotToVelocity (const Context< T > &context, const VectorBase< T > &qdot, VectorBase< T > *generalized_velocity) const
 Transforms the time derivative qdot of the generalized configuration q to generalized velocities v. More...
 
void MapQDotToVelocity (const Context< T > &context, const Eigen::Ref< const VectorX< T >> &qdot, VectorBase< T > *generalized_velocity) const
 Transforms the given time derivative qdot of generalized configuration q to generalized velocity v. More...
 
std::string GetMemoryObjectName () const
 Returns a name for this System based on a stringification of its type name and memory address. More...
 
const InputPort< T > & get_input_port (int port_index) const
 Returns the typed input port at index port_index. More...
 
const OutputPort< T > & get_output_port (int port_index) const
 Returns the typed output port at index port_index. More...
 
int get_num_constraints () const
 Returns the number of constraints specified for the system. More...
 
const SystemConstraint< T > & get_constraint (SystemConstraintIndex constraint_index) const
 Returns the constraint at index constraint_index. More...
 
bool CheckSystemConstraintsSatisfied (const Context< T > &context, double tol) const
 Returns true if context satisfies all of the registered SystemConstraints with tolerance tol. More...
 
void CheckValidOutput (const SystemOutput< T > *output) const
 Checks that output is consistent with the number and size of output ports declared by the system. More...
 
template<typename T1 = T>
void CheckValidContextT (const Context< T1 > &context) const
 Checks that context is consistent for this System template. More...
 
VectorX< T > CopyContinuousStateVector (const Context< T > &context) const
 Returns a copy of the continuous state vector xc into an Eigen vector. More...
 
std::string GetGraphvizString () const
 Returns a Graphviz string describing this System. More...
 
int64_t GetGraphvizId () const
 Returns an opaque integer that uniquely identifies this system in the Graphviz output. More...
 
void FixInputPortsFrom (const System< double > &other_system, const Context< double > &other_context, Context< T > *target_context) const
 Fixes all of the input ports in target_context to their current values in other_context, as evaluated by other_system. More...
 
const SystemScalarConverterget_system_scalar_converter () const
 (Advanced) Returns the SystemScalarConverter for this object. More...
 
std::unique_ptr< System< AutoDiffXd > > ToAutoDiffXd () const
 Creates a deep copy of this System, transmogrified to use the autodiff scalar type, with a dynamic-sized vector of partial derivatives. More...
 
std::unique_ptr< System< AutoDiffXd > > ToAutoDiffXdMaybe () const
 Creates a deep copy of this system exactly like ToAutoDiffXd(), but returns nullptr if this System does not support autodiff, instead of throwing an exception. More...
 
std::unique_ptr< System< symbolic::Expression > > ToSymbolic () const
 Creates a deep copy of this System, transmogrified to use the symbolic scalar type. More...
 
std::unique_ptr< System< symbolic::Expression > > ToSymbolicMaybe () const
 Creates a deep copy of this system exactly like ToSymbolic(), but returns nullptr if this System does not support symbolic, instead of throwing an exception. More...
 
- Public Member Functions inherited from SystemBase
 ~SystemBase () override
 
void set_name (const std::string &name)
 Sets the name of the system. More...
 
const std::string & get_name () const
 Returns the name last supplied to set_name(), if any. More...
 
const std::string & GetSystemName () const final
 Returns a human-readable name for this system, for use in messages and logging. More...
 
std::string GetSystemPathname () const final
 Generates and returns a human-readable full path name of this subsystem, for use in messages and logging. More...
 
std::string GetSystemType () const final
 Returns the most-derived type of this concrete System object as a human-readable string suitable for use in error messages. More...
 
void ThrowIfContextNotCompatible (const ContextBase &context) const final
 Throws an exception with an appropriate message if the given context is not compatible with this System. More...
 
std::unique_ptr< ContextBaseAllocateContext () const
 Returns a Context suitable for use with this System. More...
 
int get_num_input_ports () const
 Returns the number of input ports currently allocated in this System. More...
 
int get_num_output_ports () const
 Returns the number of output ports currently allocated in this System. More...
 
const InputPortBaseget_input_port_base (InputPortIndex port_index) const
 Returns a reference to an InputPort given its port_index. More...
 
const OutputPortBaseget_output_port_base (OutputPortIndex port_index) const
 Returns a reference to an OutputPort given its port_index. More...
 
int get_num_total_inputs () const
 Returns the total dimension of all of the vector-valued input ports (as if they were muxed). More...
 
int get_num_total_outputs () const
 Returns the total dimension of all of the vector-valued output ports (as if they were muxed). More...
 
int num_cache_entries () const
 Returns the number nc of cache entries currently allocated in this System. More...
 
const CacheEntryget_cache_entry (CacheIndex index) const
 Return a reference to a CacheEntry given its index. More...
 
void CheckValidContext (const ContextBase &context) const
 Checks whether the given context is valid for this System and throws an exception with a helpful message if not. More...
 
 SystemBase (const SystemBase &)=delete
 
SystemBaseoperator= (const SystemBase &)=delete
 
 SystemBase (SystemBase &&)=delete
 
SystemBaseoperator= (SystemBase &&)=delete
 
const AbstractValueEvalAbstractInput (const ContextBase &context, int port_index) const
 Returns the value of the input port with the given port_index as an AbstractValue, which is permitted for ports of any type. More...
 
template<typename V >
const V * EvalInputValue (const ContextBase &context, int port_index) const
 Returns the value of an abstract-valued input port with the given port_index as a value of known type V. More...
 
const CacheEntryDeclareCacheEntry (std::string description, CacheEntry::AllocCallback alloc_function, CacheEntry::CalcCallback calc_function, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 Declares a new CacheEntry in this System using the least-restrictive definitions for the associated functions. More...
 
template<class MySystem , class MyContext , typename ValueType >
const CacheEntryDeclareCacheEntry (std::string description, ValueType(MySystem::*make)() const, void(MySystem::*calc)(const MyContext &, ValueType *) const, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 Declares a cache entry by specifying member functions to use both for the allocator and calculator. More...
 
template<class MySystem , class MyContext , typename ValueType >
const CacheEntryDeclareCacheEntry (std::string description, const ValueType &model_value, void(MySystem::*calc)(const MyContext &, ValueType *) const, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 Declares a cache entry by specifying a model value of concrete type ValueType and a calculator function that is a class member function (method) with signature: More...
 
template<class MySystem , class MyContext , typename ValueType >
const CacheEntryDeclareCacheEntry (std::string description, void(MySystem::*calc)(const MyContext &, ValueType *) const, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 Declares a cache entry by specifying only a calculator function that is a class member function (method) with signature: More...
 
DependencyTicket input_port_ticket (InputPortIndex index)
 Returns a ticket indicating dependence on the input port indicated by index. More...
 
DependencyTicket output_port_ticket (OutputPortIndex index)
 Returns a ticket indicating dependence on the output port indicated by index. More...
 
DependencyTicket cache_entry_ticket (CacheIndex index)
 Returns a ticket indicating dependence on the cache entry indicated by index. More...
 
int num_discrete_state_groups () const
 Returns the number of declared discrete state groups (each group is a vector-valued discrete state variable). More...
 
int num_abstract_states () const
 Returns the number of declared abstract state variables. More...
 
int num_numeric_parameters () const
 Returns the number of declared numeric parameters (each of these is a vector-valued parameter). More...
 
int num_abstract_parameters () const
 Returns the number of declared abstract parameters. More...
 
DependencyTicket discrete_state_ticket (DiscreteStateIndex index) const
 Returns a ticket indicating dependence on a particular discrete state variable (may be a vector). More...
 
DependencyTicket abstract_state_ticket (AbstractStateIndex index) const
 Returns a ticket indicating dependence on a particular abstract state variable. More...
 
DependencyTicket numeric_parameter_ticket (NumericParameterIndex index) const
 Returns a ticket indicating dependence on a particular numeric parameter (may be a vector). More...
 
DependencyTicket abstract_parameter_ticket (AbstractParameterIndex index) const
 Returns a ticket indicating dependence on a particular abstract parameter. More...
 

Friends

class SceneGraphTester
 
template<typename >
class SceneGraph
 
class QueryObject< T >
 
void DispatchLoadMessage (const SceneGraph< double > &)
 Dispatches an LCM load message based on the registered geometry. More...
 

Additional Inherited Members

- Static Public Member Functions inherited from System< T >
template<template< typename > class S = ::drake::systems::System>
static std::unique_ptr< S< AutoDiffXd > > ToAutoDiffXd (const S< T > &from)
 Creates a deep copy of from, transmogrified to use the autodiff scalar type, with a dynamic-sized vector of partial derivatives. More...
 
template<template< typename > class S = ::drake::systems::System>
static std::unique_ptr< S< symbolic::Expression > > ToSymbolic (const S< T > &from)
 Creates a deep copy of from, transmogrified to use the symbolic scalar type. More...
 
- Static Public Member Functions inherited from SystemBase
static DependencyTicket all_sources_ticket ()
 Returns a ticket indicating dependence on every possible independent source value, including time, state, input ports, parameters, and the accuracy setting (but not cache entries). More...
 
static DependencyTicket nothing_ticket ()
 Returns a ticket indicating that a computation does not depend on any source value; that is, it is a constant. More...
 
static DependencyTicket time_ticket ()
 Returns a ticket indicating dependence on time. More...
 
static DependencyTicket accuracy_ticket ()
 Returns a ticket indicating dependence on the accuracy setting in the Context. More...
 
static DependencyTicket q_ticket ()
 Returns a ticket indicating that a computation depends on configuration state variables q. More...
 
static DependencyTicket v_ticket ()
 Returns a ticket indicating dependence on velocity state variables v. More...
 
static DependencyTicket z_ticket ()
 Returns a ticket indicating dependence on all of the miscellaneous continuous state variables z. More...
 
static DependencyTicket xc_ticket ()
 Returns a ticket indicating dependence on all of the continuous state variables q, v, or z. More...
 
static DependencyTicket xd_ticket ()
 Returns a ticket indicating dependence on all of the numerical discrete state variables, in any discrete variable group. More...
 
static DependencyTicket xa_ticket ()
 Returns a ticket indicating dependence on all of the abstract state variables in the current Context. More...
 
static DependencyTicket all_state_ticket ()
 Returns a ticket indicating dependence on all state variables x in this system, including continuous variables xc, discrete (numeric) variables xd, and abstract state variables xa. More...
 
static DependencyTicket xcdot_ticket ()
 Returns a ticket for the cache entry that holds time derivatives of the continuous variables. More...
 
static DependencyTicket xdhat_ticket ()
 Returns a ticket for the cache entry that holds the discrete state update for the numerical discrete variables in the state. More...
 
static DependencyTicket configuration_ticket ()
 Returns a ticket indicating dependence on all the configuration variables for this System. More...
 
static DependencyTicket velocity_ticket ()
 (Advanced) Returns a ticket indicating dependence on all of the velocity variables, but not the configuration variables for this System. More...
 
static DependencyTicket kinematics_ticket ()
 Returns a ticket indicating dependence on all of the configuration and velocity state variables of this System. More...
 
static DependencyTicket all_parameters_ticket ()
 Returns a ticket indicating dependence on all parameters p in this system, including numeric parameters pn, and abstract parameters pa. More...
 
static DependencyTicket all_input_ports_ticket ()
 Returns a ticket indicating dependence on all input ports u of this system. More...
 
- Protected Member Functions inherited from LeafSystem< T >
 LeafSystem ()
 Default constructor that declares no inputs, outputs, state, parameters, events, nor scalar-type conversion support (AutoDiff, etc.). More...
 
 LeafSystem (SystemScalarConverter converter)
 Constructor that declares no inputs, outputs, state, parameters, or events, but allows subclasses to declare scalar-type conversion support (AutoDiff, etc.). More...
 
virtual void DoValidateAllocatedLeafContext (const LeafContext< T > &context) const
 Derived classes that impose restrictions on what resources are permitted should check those restrictions by implementing this. More...
 
DoCalcWitnessValue (const Context< T > &context, const WitnessFunction< T > &witness_func) const final
 Derived classes will implement this method to evaluate a witness function at the given context. More...
 
void AddTriggeredWitnessFunctionToCompositeEventCollection (Event< T > *event, CompositeEventCollection< T > *events) const final
 Add event to events due to a witness function triggering. More...
 
void DoCalcNextUpdateTime (const Context< T > &context, CompositeEventCollection< T > *events, T *time) const override
 Computes the next update time based on the configured periodic events, for scalar types that are arithmetic, or aborts for scalar types that are not arithmetic. More...
 
BasicVector< T > * DoAllocateInputVector (const InputPort< T > &descriptor) const override
 Allocates a vector that is suitable as an input value for descriptor. More...
 
AbstractValueDoAllocateInputAbstract (const InputPort< T > &descriptor) const override
 Allocates an AbstractValue suitable as an input value for descriptor. More...
 
void GetGraphvizFragment (std::stringstream *dot) const override
 Emits a graphviz fragment for this System. More...
 
void GetGraphvizInputPortToken (const InputPort< T > &port, std::stringstream *dot) const final
 Appends a fragment to the dot stream identifying the graphviz node representing port. More...
 
void GetGraphvizOutputPortToken (const OutputPort< T > &port, std::stringstream *dot) const final
 Appends a fragment to the dot stream identifying the graphviz node representing port. More...
 
virtual std::unique_ptr< ContinuousState< T > > AllocateContinuousState () const
 Returns a ContinuousState used to implement both CreateDefaultContext and AllocateTimeDerivatives. More...
 
virtual std::unique_ptr< DiscreteValues< T > > AllocateDiscreteState () const
 Reserves the discrete state as required by CreateDefaultContext. More...
 
virtual std::unique_ptr< AbstractValuesAllocateAbstractState () const
 Reserves the abstract state as required by CreateDefaultContext. More...
 
virtual std::unique_ptr< Parameters< T > > AllocateParameters () const
 Reserves the parameters as required by CreateDefaultContext. More...
 
int DeclareNumericParameter (const BasicVector< T > &model_vector)
 Declares a numeric parameter using the given model_vector. More...
 
template<template< typename > class U = BasicVector>
const U< T > & GetNumericParameter (const Context< T > &context, int index) const
 Extracts the numeric parameters of type U from the context at index. More...
 
template<template< typename > class U = BasicVector>
U< T > & GetMutableNumericParameter (Context< T > *context, int index) const
 Extracts the numeric parameters of type U from the context at index. More...
 
int DeclareAbstractParameter (const AbstractValue &model_value)
 Declares an abstract parameter using the given model_value. More...
 
template<typename EventType >
void DeclarePeriodicEvent (double period_sec, double offset_sec)
 Declares that this System has a simple, fixed-period event specified with no custom callback function, and its attribute field contains an Event<T>::PeriodicAttribute constructed from the specified period_sec and offset_sec. More...
 
template<typename EventType >
void DeclarePeriodicEvent (double period_sec, double offset_sec, const EventType &event)
 Declares that this System has a simple, fixed-period event specified by event. More...
 
void DeclarePeriodicDiscreteUpdate (double period_sec, double offset_sec=0)
 Declares a periodic discrete update event with period = period_sec and offset = offset_sec. More...
 
void DeclarePeriodicUnrestrictedUpdate (double period_sec, double offset_sec=0)
 Declares a periodic unrestricted update event with period = period_sec and offset = offset_sec. More...
 
void DeclarePeriodicPublish (double period_sec, double offset_sec=0)
 Declares a periodic publish event with period = period_sec and offset = offset_sec. More...
 
template<typename EventType >
void DeclarePerStepEvent (const EventType &event)
 Declares a per-step event using event, which is deep copied (the copy is maintained by this). More...
 
template<typename EventType >
void DeclareInitializationEvent (const EventType &event)
 Declares an initialization event by deep copying event and storing it internally. More...
 
void DeclareContinuousState (int num_state_variables)
 Declares that this System should reserve continuous state with num_state_variables state variables, which have no second-order structure. More...
 
void DeclareContinuousState (int num_q, int num_v, int num_z)
 Declares that this System should reserve continuous state with num_q generalized positions, num_v generalized velocities, and num_z miscellaneous state variables. More...
 
void DeclareContinuousState (const BasicVector< T > &model_vector)
 Declares that this System should reserve continuous state with model_vector.size() miscellaneous state variables, stored in a vector Cloned from model_vector. More...
 
void DeclareContinuousState (const BasicVector< T > &model_vector, int num_q, int num_v, int num_z)
 Declares that this System should reserve continuous state with num_q generalized positions, num_v generalized velocities, and num_z miscellaneous state variables, stored in a vector Cloned from model_vector. More...
 
void DeclareContinuousState (std::unique_ptr< BasicVector< T >> model_vector, int num_q, int num_v, int num_z)
 Declares that this System should reserve continuous state with num_q generalized positions, num_v generalized velocities, and num_z miscellaneous state variables, stored in the a vector Cloned from model_vector. More...
 
void DeclareDiscreteState (int num_state_variables)
 Declares that this System should reserve discrete state with num_state_variables state variables. More...
 
int DeclareAbstractState (std::unique_ptr< AbstractValue > abstract_state)
 Declares an abstract state. More...
 
template<class MySystem >
SystemConstraintIndex DeclareEqualityConstraint (void(MySystem::*calc)(const Context< T > &, VectorX< T > *) const, int count, const std::string &description)
 Declares a system constraint of the form f(context) = 0 by specifying a member function to use to calculate the (VectorX) constraint value with a signature: More...
 
SystemConstraintIndex DeclareEqualityConstraint (typename SystemConstraint< T >::CalcCallback calc, int count, const std::string &description)
 Declares a system constraint of the form f(context) = 0 by specifying a std::function to use to calculate the (Vector) constraint value with a signature: More...
 
template<class MySystem >
SystemConstraintIndex DeclareInequalityConstraint (void(MySystem::*calc)(const Context< T > &, VectorX< T > *) const, int count, const std::string &description)
 Declares a system constraint of the form f(context) ≥ 0 by specifying a member function to use to calculate the (VectorX) constraint value with a signature: More...
 
SystemConstraintIndex DeclareInequalityConstraint (typename SystemConstraint< T >::CalcCallback calc, int count, const std::string &description)
 Declares a system constraint of the form f(context) ≥ 0 by specifying a std::function to use to calculate the (Vector) constraint value with a signature: More...
 
virtual void DoPublish (const Context< T > &context, const std::vector< const PublishEvent< T > * > &events) const
 Derived-class event handler for all simultaneous publish events in events. More...
 
virtual void DoCalcDiscreteVariableUpdates (const Context< T > &context, const std::vector< const DiscreteUpdateEvent< T > * > &events, DiscreteValues< T > *discrete_state) const
 Derived-class event handler for all simultaneous discrete update events. More...
 
virtual void DoCalcUnrestrictedUpdate (const Context< T > &context, const std::vector< const UnrestrictedUpdateEvent< T > * > &events, State< T > *state) const
 Derived-class event handler for all simultaneous unrestricted update events. More...
 
const InputPort< T > & DeclareVectorInputPort (const BasicVector< T > &model_vector, optional< RandomDistribution > random_type=nullopt)
 Declares a vector-valued input port using the given model_vector. More...
 
const InputPort< T > & DeclareAbstractInputPort (const AbstractValue &model_value)
 Declares an abstract-valued input port using the given model_value. More...
 
template<class MySystem >
std::unique_ptr< WitnessFunction< T > > DeclareWitnessFunction (const std::string &description, const WitnessFunctionDirection &direction_type, T(MySystem::*calc)(const Context< T > &) const) const
 Constructs the witness function with the given description (used primarily for debugging and logging), direction type, and calculator function; and with no event object. More...
 
std::unique_ptr< WitnessFunction< T > > DeclareWitnessFunction (const std::string &description, const WitnessFunctionDirection &direction_type, std::function< T(const Context< T > &)> calc) const
 Constructs the witness function with the given description (used primarily for debugging and logging), direction type, and calculator function; and with no event object. More...
 
template<class MySystem >
std::unique_ptr< WitnessFunction< T > > DeclareWitnessFunction (const std::string &description, const WitnessFunctionDirection &direction_type, T(MySystem::*calc)(const Context< T > &) const, void(MySystem::*publish_callback)(const Context< T > &, const PublishEvent< T > &) const) const
 Constructs the witness function with the given description (used primarily for debugging and logging), direction type, calculator function, and publish event callback function for when this triggers. More...
 
template<class MySystem >
std::unique_ptr< WitnessFunction< T > > DeclareWitnessFunction (const std::string &description, const WitnessFunctionDirection &direction_type, T(MySystem::*calc)(const Context< T > &) const, void(MySystem::*du_callback)(const Context< T > &, const DiscreteUpdateEvent< T > &, DiscreteValues< T > *) const) const
 Constructs the witness function with the given description (used primarily for debugging and logging), direction type, calculator function, and discrete update event callback function for when this triggers. More...
 
template<class MySystem >
std::unique_ptr< WitnessFunction< T > > DeclareWitnessFunction (const std::string &description, const WitnessFunctionDirection &direction_type, T(MySystem::*calc)(const Context< T > &) const, void(MySystem::*uu_callback)(const Context< T > &, const UnrestrictedUpdateEvent< T > &, State< T > *) const) const
 Constructs the witness function with the given description (used primarily for debugging and logging), direction type, calculator function, and unrestricted update event callback function for when this triggers. More...
 
template<class MySystem >
std::unique_ptr< WitnessFunction< T > > DeclareWitnessFunction (const std::string &description, const WitnessFunctionDirection &direction_type, T(MySystem::*calc)(const Context< T > &) const, const Event< T > &e) const
 Constructs the witness function with the given description (used primarily for debugging and logging), direction type, and calculator function, and with an object corresponding to the event that is to be dispatched when this witness function triggers. More...
 
std::unique_ptr< WitnessFunction< T > > DeclareWitnessFunction (const std::string &description, const WitnessFunctionDirection &direction_type, std::function< T(const Context< T > &)> calc, const Event< T > &e) const
 Constructs the witness function with the given description (used primarily for debugging and logging), direction type, and calculator function, and with an object corresponding to the event that is to be dispatched when this witness function triggers. More...
 
template<class MySystem , typename BasicVectorSubtype >
const OutputPort< T > & DeclareVectorOutputPort (const BasicVectorSubtype &model_vector, void(MySystem::*calc)(const Context< T > &, BasicVectorSubtype *) const, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 Declares a vector-valued output port by specifying (1) a model vector of type BasicVectorSubtype derived from BasicVector and initialized to the correct size and desired initial value, and (2) a calculator function that is a class member function (method) with signature: More...
 
template<class MySystem , typename BasicVectorSubtype >
const OutputPort< T > & DeclareVectorOutputPort (void(MySystem::*calc)(const Context< T > &, BasicVectorSubtype *) const, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 Declares a vector-valued output port by specifying only a calculator function that is a class member function (method) with signature: More...
 
const OutputPort< T > & DeclareVectorOutputPort (const BasicVector< T > &model_vector, typename LeafOutputPort< T >::CalcVectorCallback vector_calc_function, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 (Advanced) Declares a vector-valued output port using the given model_vector and a function for calculating the port's value at runtime. More...
 
template<class MySystem , typename OutputType >
const OutputPort< T > & DeclareAbstractOutputPort (const OutputType &model_value, void(MySystem::*calc)(const Context< T > &, OutputType *) const, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 Declares an abstract-valued output port by specifying a model value of concrete type OutputType and a calculator function that is a class member function (method) with signature: More...
 
template<class MySystem , typename OutputType >
const OutputPort< T > & DeclareAbstractOutputPort (void(MySystem::*calc)(const Context< T > &, OutputType *) const, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 Declares an abstract-valued output port by specifying only a calculator function that is a class member function (method) with signature: More...
 
template<class MySystem , typename OutputType >
const OutputPort< T > & DeclareAbstractOutputPort (OutputType(MySystem::*make)() const, void(MySystem::*calc)(const Context< T > &, OutputType *) const, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 Declares an abstract-valued output port by specifying member functions to use both for the allocator and calculator. More...
 
const OutputPort< T > & DeclareAbstractOutputPort (typename LeafOutputPort< T >::AllocCallback alloc_function, typename LeafOutputPort< T >::CalcCallback calc_function, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 (Advanced) Declares an abstract-valued output port using the given allocator and calculator functions provided in their most generic forms. More...
 
- Protected Member Functions inherited from System< T >
virtual void DoGetWitnessFunctions (const Context< T > &, std::vector< const WitnessFunction< T > * > *) const
 Derived classes can override this method to provide witness functions active for the given state. More...
 
SystemConstraintIndex AddConstraint (std::unique_ptr< SystemConstraint< T >> constraint)
 Adds an already-created constraint to the list of constraints for this System. More...
 
const EventCollection< PublishEvent< T > > & get_forced_publish_events () const
 
const EventCollection< DiscreteUpdateEvent< T > > & get_forced_discrete_update_events () const
 
const EventCollection< UnrestrictedUpdateEvent< T > > & get_forced_unrestricted_update_events () const
 
void set_forced_publish_events (std::unique_ptr< EventCollection< PublishEvent< T >>> forced)
 
void set_forced_discrete_update_events (std::unique_ptr< EventCollection< DiscreteUpdateEvent< T >>> forced)
 
void set_forced_unrestricted_update_events (std::unique_ptr< EventCollection< UnrestrictedUpdateEvent< T >>> forced)
 
 System (SystemScalarConverter converter)
 Constructs an empty System base class object, possibly supporting scalar-type conversion support (AutoDiff, etc.) using converter. More...
 
const InputPort< T > & DeclareInputPort (PortDataType type, int size, optional< RandomDistribution > random_type=nullopt)
 Adds a port with the specified type and size to the input topology. More...
 
const InputPort< T > & DeclareAbstractInputPort ()
 Adds an abstract-valued port to the input topology. More...
 
virtual void DoCalcTimeDerivatives (const Context< T > &context, ContinuousState< T > *derivatives) const
 Override this if you have any continuous state variables xc in your concrete System to calculate their time derivatives. More...
 
virtual T DoCalcPotentialEnergy (const Context< T > &context) const
 Override this method for physical systems to calculate the potential energy currently stored in the configuration provided in the given Context. More...
 
virtual T DoCalcKineticEnergy (const Context< T > &context) const
 Override this method for physical systems to calculate the kinetic energy currently present in the motion provided in the given Context. More...
 
virtual T DoCalcConservativePower (const Context< T > &context) const
 Override this method to return the rate at which mechanical energy is being converted from potential energy to kinetic energy by this system in the given Context. More...
 
virtual T DoCalcNonConservativePower (const Context< T > &context) const
 Override this method to return the rate at which mechanical energy is being generated (positive) or dissipated (negative) other than by conversion between potential and kinetic energy (in the given Context). More...
 
virtual void DoMapQDotToVelocity (const Context< T > &context, const Eigen::Ref< const VectorX< T >> &qdot, VectorBase< T > *generalized_velocity) const
 Provides the substantive implementation of MapQDotToVelocity(). More...
 
virtual void DoMapVelocityToQDot (const Context< T > &context, const Eigen::Ref< const VectorX< T >> &generalized_velocity, VectorBase< T > *qdot) const
 Provides the substantive implementation of MapVelocityToQDot(). More...
 
virtual int do_get_num_constraint_equations (const Context< T > &context) const
 Gets the number of constraint equations for this system from the given context. More...
 
virtual Eigen::VectorXd DoEvalConstraintEquations (const Context< T > &context) const
 Evaluates the constraint equations for the system at the generalized coordinates and generalized velocity specified by the context. More...
 
virtual Eigen::VectorXd DoEvalConstraintEquationsDot (const Context< T > &context) const
 Computes the time derivative of each constraint equation, evaluated at the generalized coordinates and generalized velocity specified by the context. More...
 
virtual Eigen::VectorXd DoCalcVelocityChangeFromConstraintImpulses (const Context< T > &context, const Eigen::MatrixXd &J, const Eigen::VectorXd &lambda) const
 Computes the change in velocity from applying the given constraint forces to the system at the given context. More...
 
virtual double DoCalcConstraintErrorNorm (const Context< T > &context, const Eigen::VectorXd &error) const
 Computes the norm of the constraint error. More...
 
Eigen::VectorBlock< VectorX< T > > GetMutableOutputVector (SystemOutput< T > *output, int port_index) const
 Returns a mutable Eigen expression for a vector valued output port with index port_index in this system. More...
 
- Protected Member Functions inherited from SystemBase
 SystemBase ()=default
 (Internal use only) Default constructor. More...
 
void AddInputPort (std::unique_ptr< InputPortBase > port)
 (Internal use only) Adds an already-constructed input port to this System. More...
 
void AddOutputPort (std::unique_ptr< OutputPortBase > port)
 (Internal use only) Adds an already-constructed output port to this System. More...
 
void AddDiscreteStateGroup (DiscreteStateIndex index)
 (Internal use only) Assigns a ticket to a new discrete variable group with the given index. More...
 
void AddAbstractState (AbstractStateIndex index)
 (Internal use only) Assigns a ticket to a new abstract state variable with the given index. More...
 
void AddNumericParameter (NumericParameterIndex index)
 (Internal use only) Assigns a ticket to a new numeric parameter with the given index. More...
 
void AddAbstractParameter (AbstractParameterIndex index)
 (Internal use only) Assigns a ticket to a new abstract parameter with the given index. More...
 
const CacheEntryDeclareCacheEntryWithKnownTicket (DependencyTicket known_ticket, std::string description, CacheEntry::AllocCallback alloc_function, CacheEntry::CalcCallback calc_function, std::set< DependencyTicket > prerequisites_of_calc={all_sources_ticket()})
 (Internal use only) This is for cache entries associated with pre-defined tickets, for example the cache entry for time derivatives. More...
 
const internal::SystemParentServiceInterface * get_parent_service () const
 Returns a pointer to the service interface of the immediately enclosing Diagram if one has been set, otherwise nullptr. More...
 
DependencyTicket assign_next_dependency_ticket ()
 (Internal use only) Assigns the next unused dependency ticket number, unique only within a particular system. More...
 
const AbstractValueEvalAbstractInputImpl (const char *func, const ContextBase &context, InputPortIndex port_index) const
 (Internal use only) Shared code for updating an input port and returning a pointer to its abstract value, or nullptr if the port is not connected. More...
 
void ThrowNegativePortIndex (const char *func, int port_index) const
 Throws std::out_of_range to report a negative port_index that was passed to API method func. More...
 
void ThrowInputPortIndexOutOfRange (const char *func, InputPortIndex port_index) const
 Throws std::out_of_range to report bad input port_index that was passed to API method func. More...
 
void ThrowOutputPortIndexOutOfRange (const char *func, OutputPortIndex port_index) const
 Throws std::out_of_range to report bad output port_index that was passed to API method func. More...
 
void ThrowNotAVectorInputPort (const char *func, InputPortIndex port_index) const
 Throws std::logic_error because someone misused API method func, that is only allowed for declared-vector input ports, on an abstract port whose index is given here. More...
 
void ThrowInputPortHasWrongType (const char *func, InputPortIndex port_index, const std::string &expected_type, const std::string &actual_type) const
 Throws std::logic_error because someone called API method func claiming the input port had some value type that was wrong. More...
 
void ThrowCantEvaluateInputPort (const char *func, InputPortIndex port_index) const
 Throws std::logic_error because someone called API method func, that requires this input port to be evaluatable, but the port was neither fixed nor connected. More...
 
const InputPortBaseGetInputPortBaseOrThrow (const char *func, int port_index) const
 (Internal use only) Returns the InputPortBase at index port_index, throwing std::out_of_range we don't like the port index. More...
 
const OutputPortBaseGetOutputPortBaseOrThrow (const char *func, int port_index) const
 (Internal use only) Returns the OutputPortBase at index port_index, throwing std::out_of_range we don't like the port index. More...
 
void InitializeContextBase (ContextBase *context) const
 This method must be invoked from within derived class DoAllocateContext() implementations right after the concrete Context object has been allocated. More...
 
- Static Protected Member Functions inherited from SystemBase
static void set_parent_service (SystemBase *child, const internal::SystemParentServiceInterface *parent_service)
 (Internal use only) Declares that parent_service is the service interface of the Diagram that owns this subsystem. More...
 

Detailed Description

template<typename T>
class drake::geometry::SceneGraph< T >

SceneGraph serves as the nexus for all geometry (and geometry-based operations) in a Diagram.

Through SceneGraph, other systems that introduce geometry can register that geometry as part of a common global domain, including it in geometric queries (e.g., cars controlled by one LeafSystem can be observed by a different sensor system). SceneGraph provides the interface for registering the geometry, updating its position based on the current context, and performing geometric queries.

Only registered "geometry sources" can introduce geometry into SceneGraph. Geometry sources will typically be other leaf systems, but, in the case of anchored (i.e., stationary) geometry, it could also be some other block of code (e.g., adding a common ground plane with which all systems' geometries interact). For dynamic geometry (geometry whose pose depends on a Context), the geometry source must also provide pose values for all of the geometries the source owns, via a port connection on SceneGraph.

The basic workflow for interacting with SceneGraph is:

  • Register as a geometry source, acquiring a unique SourceId.
  • Register geometry (anchored and dynamic) with the system.
  • Connect source's geometry output ports to the corresponding SceneGraph input ports.
    • Implement appropriate Calc* methods on the geometry output ports to update geometry pose values.

Inputs

For each registered geometry source, there is one input port for each order of kinematics values (e.g., pose, velocity, and acceleration). If a source registers a frame, it must connect to these ports (although, in the current version, only pose is supported). Failure to connect to the port (or to provide valid kinematics values) will lead to runtime exceptions.

pose port: An abstract-valued port providing an instance of FramePoseVector. For each registered frame, this "pose vector" maps the registered FrameId to a pose value. All registered frames must be accounted for and only frames registered by a source can be included in its output port. See the details in FrameKinematicsVector for details on how to allocate and calculate this port.

Outputs

SceneGraph has two output ports:

query port: An abstract-valued port containing an instance of QueryObject. It provides a "ticket" for downstream LeafSystem instances to perform geometric queries on the SceneGraph. To perform geometric queries, downstream LeafSystem instances acquire the QueryObject from SceneGraph's output port and provide it as a parameter to one of SceneGraph's query methods (e.g., SceneGraph::ComputeContact()). This assumes that the querying system has access to a const pointer to the connected SceneGraph instance. Use get_query_output_port() to acquire the output port for the query handle.

lcm visualization port: An abstract-valued port containing an instance of PoseBundle. This is a convenience port designed to feed LCM update messages to drake_visualizer for the purpose of visualizing the state of the world's geometry. Additional uses of this port are strongly discouraged; instead, use an appropriate geometric query to obtain the state of the world's geometry.

Working with SceneGraph

LeafSystem instances can relate to SceneGraph in one of two ways: as a consumer that performs queries, or as a producer that introduces geometry into the shared world and defines its context-dependent kinematics values. It is reasonable for systems to perform either role singly, or both.

Consumer

Consumers perform geometric queries upon the world geometry. SceneGraph serves those queries. As indicated above, in order for a LeafSystem to act as a consumer, it must:

  1. define a QueryObject-valued input port and connect it to SceneGraph's corresponding output port, and
  2. have a reference to the connected SceneGraph instance.

With those two requirements satisfied, a LeafSystem can perform geometry queries by:

  1. evaluating the QueryObject input port, and
  2. passing the returned query object into the appropriate query method on SceneGraph (e.g., SceneGraph::ComputeContact()).

Producer

All producers introduce geometry into the shared geometric world. This is called registering geometry. Depending on what exactly has been registered, a producer may also have to update kinematics. Producers themselves must be registered with SceneGraph as producers (a.k.a. geometry sources). They do this by acquiring a SourceId (via SceneGraph::RegisterSource()). The SourceId serves as a unique handle through which the producer's identity is validated and its ownership of its registered geometry is maintained.

Registering Geometry

SceneGraph cannot know what geometry should be part of the shared world. Other systems are responsible for introducing geometry into the world. This process (defining geometry and informing SceneGraph) is called registering the geometry. The source that registers the geometry "owns" the geometry; the source's unique SourceId is required to perform any operations on the geometry registered with that SourceId. Geometry can be registered as anchored or dynamic.

Dynamic geometry can move; more specifically, its kinematics (e.g., pose) depends on a system's Context. Particularly, dynamic geometry is fixed to a frame whose kinematics values depend on a context. As the frame moves, the geometries fixed to it move with it. Therefore, to register dynamic geometry a frame must be registered first. These registered frames serve as the basis for repositioning geometry in the shared world. The geometry source is responsible for providing up-to-date kinematics values for those registered frames upon request (via an appropriate output port on the source LeafSystem connecting to the appropriate input port on SceneGraph). The work flow is as follows:

  1. A LeafSystem registers itself as a geometry source, acquiring a SourceId (RegisterSource()).
  2. The source registers a frame (GeometrySource::RegisterFrame()).
    • A frame always has a "parent" frame. It can implicitly be the world frame, or another frame registered by the source.
  3. Register one or more geometries to a frame (GeometrySource::RegisterGeometry()).
    • The registered geometry is posed relative to the frame to which it is fixed.
    • The geometry can also be posed relative to another registered geometry. It will be affixed to that geometry's frame.

Anchored geometry is independent of the context (i.e., it doesn't move). Anchored geometries are always affixed to the immobile world frame. As such, registering a frame is not required for registering anchored geometry (see GeometrySource::RegisterAnchoredGeometry()). However, the source still "owns" the anchored geometry.

Updating Kinematics

Registering dynamic geometry implies a contract between the geometry source and SceneGraph. The geometry source must do the following:

  • It must provide, populate, and connect two output ports: the "id" port and the "pose" port.
  • The id port must contain all the frame ids returned as a result of frame registration.
  • The pose port must contain one pose per registered frame; the pose value is expressed relative to the registered frame's parent frame. As mentioned above, the iᵗʰ pose value should describe the frame indicated by the iᵗʰ id in the id output port.

Failure to meet these requirements will lead to a run-time error.

Template Parameters
TThe scalar type. Must be a valid Eigen scalar.

Instantiated templates for the following kinds of T's are provided:

  • double
  • AutoDiffXd

They are already available to link against in the containing library. No other values for T are currently supported.

Constructor & Destructor Documentation

SceneGraph ( const SceneGraph< T > &  )
delete
SceneGraph ( SceneGraph< T > &&  )
delete

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SceneGraph ( const SceneGraph< U > &  other)
explicit

Constructor used for scalar conversions.

It should only be used to convert from double to other scalar types.

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~SceneGraph ( )
inlineoverride

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Member Function Documentation

void ExcludeCollisionsBetween ( const GeometrySet setA,
const GeometrySet setB 
)

Excludes geometry pairs from collision evaluation by updating the candidate pair set C = C - P, where P = {(a, b)}, ∀ a ∈ A, b ∈ B and A = {a₀, a₁, ..., aₘ} and B = {b₀, b₁, ..., bₙ} are the input sets of geometries setA and setB, respectively.

This does not preclude collisions between members of the same set.

Exceptions
std::logic_errorif the groups include ids that don't exist in the scene graph.

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void ExcludeCollisionsWithin ( const GeometrySet set)

Excludes geometry pairs from collision evaluation by updating the candidate pair set C = C - P, where P = {(gᵢ, gⱼ)}, ∀ gᵢ, gⱼ ∈ G and G = {g₀, g₁, ..., gₘ} is the input set of geometries.

Exceptions
std::logic_errorif the set includes ids that don't exist in the scene graph.

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const systems::OutputPort<T>& get_pose_bundle_output_port ( ) const
inline

Returns the output port which produces the PoseBundle for LCM communication to drake visualizer.

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const systems::OutputPort<T>& get_query_output_port ( ) const
inline

Returns the output port which produces the QueryObject for performing geometric queries.

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const systems::InputPort< T > & get_source_pose_port ( SourceId  id)

Given a valid source id, returns a pose input port associated with that id.

This port is used to communicate pose data for registered frames.

Exceptions
std::logic_errorif the source_id is not recognized.

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SceneGraph& operator= ( const SceneGraph< T > &  )
delete
SceneGraph& operator= ( SceneGraph< T > &&  )
delete
GeometryId RegisterAnchoredGeometry ( SourceId  source_id,
std::unique_ptr< GeometryInstance geometry 
)

Registers a new anchored geometry G for this source.

This hangs geometry G from the world frame (W). Its pose is defined in that frame (i.e., X_WG). Returns the corresponding unique geometry id.

Parameters
source_idThe id for the source registering the frame.
geometryThe anchored geometry G to add to the world.
Returns
The index for the added geometry.
Exceptions
std::logic_errorIf the source_id does not map to a registered source or a context has been allocated.

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FrameId RegisterFrame ( SourceId  source_id,
const GeometryFrame frame 
)

Registers a new frame F on for this source.

This hangs frame F on the world frame (W). Its pose is defined relative to the world frame (i.e, X_WF). Returns the corresponding unique frame id.

Parameters
source_idThe id for the source registering the frame.
frameThe definition of the frame to add.
Returns
A newly allocated frame id.
Exceptions
std::logic_errorIf the source_id does not map to a registered source or if a context has been allocated.

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FrameId RegisterFrame ( SourceId  source_id,
FrameId  parent_id,
const GeometryFrame frame 
)

Registers a new frame F for this source.

This hangs frame F on another previously registered frame P (indicated by parent_id). The pose of the new frame is defined relative to the parent frame (i.e., X_PF). Returns the corresponding unique frame id.

Parameters
source_idThe id for the source registering the frame.
parent_idThe id of the parent frame P.
frameThe frame to register.
Returns
A newly allocated frame id.
Exceptions
std::logic_error1. If the source_id does not map to a registered source,
  1. If the parent_id does not map to a known frame or does not belong to the source, or
  2. a context has been allocated.
GeometryId RegisterGeometry ( SourceId  source_id,
FrameId  frame_id,
std::unique_ptr< GeometryInstance geometry 
)

Registers a new geometry G for this source.

This hangs geometry G on a previously registered frame F (indicated by frame_id). The pose of the geometry is defined in a fixed pose relative to F (i.e., X_FG). Returns the corresponding unique geometry id.

Parameters
source_idThe id for the source registering the geometry.
frame_idThe id for the frame F to hang the geometry on.
geometryThe geometry G to affix to frame F.
Returns
A unique identifier for the added geometry.
Exceptions
std::logic_error1. the source_id does not map to a registered source,
  1. the frame_id doesn't belong to the source,
  2. the geometry is equal to nullptr,
  3. a context has been allocated.

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GeometryId RegisterGeometry ( SourceId  source_id,
GeometryId  geometry_id,
std::unique_ptr< GeometryInstance geometry 
)

Registers a new geometry G for this source.

This hangs geometry G on a previously registered geometry P (indicated by geometry_id). The pose of the geometry is defined in a fixed pose relative to geometry P (i.e., X_PG). By induction, this geometry is effectively rigidly affixed to the frame that P is affixed to. Returns the corresponding unique geometry id.

Parameters
source_idThe id for the source registering the geometry.
geometry_idThe id for the parent geometry P.
geometryThe geometry G to add.
Returns
A unique identifier for the added geometry.
Exceptions
std::logic_error1. the source_id does not map to a registered source,
  1. the geometry_id doesn't belong to the source,
  2. the geometry is equal to nullptr, or
  3. a context has been allocated.
SourceId RegisterSource ( const std::string &  name = "")

Registers a new source to the geometry system.

The caller must save the returned SourceId; it is the token by which all other operations on the geometry world are conducted.

This source id can be used to register arbitrary anchored geometry. But if dynamic geometry is registered (via RegisterGeometry/RegisterFrame), then the context-dependent pose values must be provided on an input port. See get_source_pose_port().

Parameters
nameThe optional name of the source. If none is provided (or the empty string) a unique name will be defined by SceneGraph's logic.
Exceptions
std::logic_errorif a context has already been allocated for this SceneGraph.
See also
GeometryState::RegisterNewSource()

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bool SourceIsRegistered ( SourceId  id) const

Reports if the given source id is registered.

Parameters
idThe id of the source to query.

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Friends And Related Function Documentation

void DispatchLoadMessage ( const SceneGraph< double > &  )
friend

Dispatches an LCM load message based on the registered geometry.

It should be invoked after registration is complete, but before context allocation.

Parameters
scene_graphThe system whose geometry will be sent in an LCM message.
Exceptions
std::logic_errorif the system has already had its context allocated.
friend class QueryObject< T >
friend
friend class SceneGraph
friend
friend class SceneGraphTester
friend

The documentation for this class was generated from the following files: