Gazebo Gazebo

API Reference

3.15.1

Migration from Gazebo-classic: Link API

When migrating plugins from Gazebo-classic to Ignition Gazebo, developers will notice that the C++ APIs for both simulators are quite different. Be sure to check the plugin migration tutorial to get a high-level view of the architecture differences before using this guide.

This tutorial is meant to serve as a reference guide for developers migrating functions from the sim::phyiscs::Link class.

If you're trying to use some API which doesn't have an equivalent on Ignition yet, feel free to ticket an issue.

Link API

Gazebo-classic's sim::physics::Link provides lots of functionality, which can be divided in these categories:

You'll find the Ignition APIs below on the following headers:

It's worth remembering that most of this functionality can be performed using the EntityComponentManager directly. The functions presented here exist for convenience and readability.

Properties

Most of Gazebo-classic's Link API is related to setting and getting properties. These functions are great candidates to have equivalents on Ignition Gazebo, because the Entity-Component-System architecture is perfect for setting components (properties) into entities such as links.


Classic Ignition
AddForce gz::sim::Link::AddWorldForce
AddForceAtRelativePosition TODO
AddForceAtWorldPosition TODO
AddLinkForce TODO
AddRelativeForce TODO
AddRelativeTorque TODO
AddTorque gz::sim::Link::AddWorldWrench
AddType ecm.CreateComponent<Type>(entity, Type())
Battery Use this system: gz::sim::systems::LinearBatteryPlugin
BoundingBox TODO
CollisionBoundingBox TODO
DirtyPose Not supported
FillMsg TODO
GetAngularDamping TODO
GetEnabled TODO
GetGravityMode TODO
GetId gz::sim::Link::Entity
GetInertial gz::sim::Link::WorldInertialPose / gz::sim::Link::WorldInertialMatrix
GetKinematic TODO
GetLinearDamping TODO
GetName gz::sim::Link::Name
GetSDF TODO
GetSDFDom TODO
GetSaveable Not supported
GetScopedName gz::sim::scopedName
GetSelfCollide See model API
GetSensorName See sensor API
GetType gz::sim::entityType
GetWorldEnergy TODO
GetWorldEnergyKinetic gz::sim::Link::WorldKineticEnergy
GetWorldEnergyPotential TODO
HasType sim::components::Link::typeId == entityTypeId(entity, ecm)
InitialRelativePose TODO
IsCanonicalLink gz::sim::Link::IsCanonical
IsSelected Selection is client-specific, not porting
IsStatic See model API
MoveFrame TODO
Print TODO
ProcessMsg TODO
RelativeAngularAccel TODO
RelativeAngularVel TODO
RelativeForce TODO
RelativeLinearAccel TODO
RelativeLinearVel TODO
RelativePose TODO
RelativeTorque TODO
RelativeWindLinearVel TODO
SDFPoseRelativeToParent TODO
SDFSemanticPose TODO
SetAngularDamping TODO
SetAngularVel TODO
SetAnimation TODO
SetAutoDisable TODO
SetCanonicalLink TODO
SetCollideMode TODO
SetEnabled TODO
SetForce TODO
SetGravityMode TODO
SetInertial TODO
SetInitialRelativePose TODO
SetKinematic TODO
SetLaserRetro TODO
SetLinearDamping TODO
SetLinearVel TODO
SetLinkStatic TODO
SetName TODO
SetPublishData TODO
SetRelativePose TODO
SetSaveable Not supported
SetScale TODO
SetSelected Selection is client-specific, not porting
SetSelfCollide TODO
SetState TODO
SetStatic TODO
SetTorque TODO
SetVisualPose See visual API
SetWindEnabled TODO
SetWindMode TODO
SetWorldPose TODO
SetWorldTwist TODO
StopAnimation TODO
TypeStr gz::sim::entityTypeStr
URI TODO
UpdateParameters TODO
VisualPose See visual API
WindMode gz::sim::Link::WindMode
WorldAngularAccel TODO
WorldAngularMomentum TODO
WorldAngularVel gz::sim::Link::WorldAngularVelocity
WorldCoGLinearVel TODO
WorldCoGPose TODO
WorldForce TODO
WorldInertiaMatrix gz::sim::Link::WorldInertialMatrix
WorldInertialPose gz::sim::Link::WorldInertialPose
WorldLinearAccel gz::sim::Link::WorldLinearAcceleration
WorldLinearVel gz::sim::Link::WorldLinearVelocity
WorldPose gz::sim::Link::WorldPose
WorldTorque TODO
WorldWindLinearVel TODO

Read family

These APIs deal with reading information related to child / parent relationships.

The main difference in these APIs across Gazebo generations is that on classic, they deal with shared pointers to entities, while on Ignition, they deal with entity IDs.


Classic Ignition
BatteryCount Use this system: gz::sim::systems::LinearBatteryPlugin
FindAllConnectedLinksHelper TODO
GetByName Use type-specific gz::sim::Link::*ByName
GetChild Use type-specific gz::sim::Link::*ByName
GetChildCollision gz::sim::Link::CollisionByName
GetChildCount Use type-specific gz::sim::Link::*Count
GetChildJoint TODO
GetChildJointsLinks See joint API
GetChildLink Not supported
GetCollision gz::sim::Link::CollisionByName
GetCollisions gz::sim::Link::Collisions
GetModel gz::sim::Link::ParentModel
GetParent gz::sim::EntiyComponentManager::ParentEntity
GetParentId gz::sim::EntiyComponentManager::ParentEntity
GetParentJoints TODO
GetParentJointsLinks See joint API
GetParentModel gz::sim::Link::ParentModel
GetSensorCount gz::sim::Link::SensorCount
GetVisualMessage See visual API
GetWorld gz::sim::worldEntity
VisualId gz::sim::Link::VisualByName
Visuals gz::sim::Link::Visuals

Write family

These functions deal with modifying the entity tree, attaching children to new parents.


Classic Ignition
AddChild TODO
AddChildJoint TODO
AddParentJoint TODO
AttachStaticLink TODO
AttachStaticModel TODO
CreateJoint TODO
CreateLink TODO
DetachAllStaticModels TODO
DetachStaticLink TODO
DetachStaticModel TODO
RemoveChild TODO
RemoveChildJoint TODO
RemoveChildren TODO
RemoveCollision TODO
RemoveJoint TODO
RemoveParentJoint TODO
SetCanonicalLink TODO
SetParent TODO
SetWorld TODO

Lifecycle

These functions aren't related to the state of a link, but perform some processing related to the link's lifecycle, like initializing, updating or terminating it.


Classic Ignition
Fini N/A
Init N/A
Load gz::sim::SdfEntityCreator::CreateEntities
LoadJoints gz::sim::SdfEntityCreator::CreateEntities
LoadPlugins TODO
Reset TODO
ResetPhysicsStates TODO
Update Entities are updated by systems
UpdateMass Entities are updated by systems
UpdateSurface Entities are updated by systems
UpdateWind Entities are updated by systems
OnPoseChange TODO

Others

Miscelaneous functions that don't fit the other categories. Most of them involve logic that should be performed from within a system.


Classic Ignition
GetNearestEntityBelow Requires a system
PlaceOnEntity Involves Requires a system
PlaceOnNearestEntityBelow Requires a system