# Ignition Physics

## API Reference

2.3.0
FreeGroup.hh File Reference
#include <ignition/physics/FeatureList.hh>
#include <ignition/physics/FrameSemantics.hh>
#include <ignition/physics/Geometry.hh>
#include <ignition/physics/detail/FreeGroup.hh>

Go to the source code of this file.

## Classes

class  SetFreeGroupWorldVelocity::FreeGroup< PolicyT, FeaturesT >
This class defines the FreeGroup concept, which represents a group of links that are not connected to the world with any kinematic constraints. This class also provides a rough definition of this FreeGroup linear and angular velocity in world frame. See FindFreeGroupFeature class documentation for more detail. More...

class  SetFreeGroupWorldPose::FreeGroup< PolicyT, FeaturesT >
This class defines the FreeGroup concept, which represents a group of links that are not connected to the world with any kinematic constraints. This class also provides a rough definition of this FreeGroup pose in world frame. See FindFreeGroupFeature class documentation for more detail. More...

class  FreeGroupFrameSemantics
This feature provides an interface between the Model and Link classes and the FreeGroup class, which represents a group of links that are not connected to the world with any kinematic constraints. A FreeGroup can represent a single connected group of links that forms a tree with the root of the tree connected to the world with a FreeJoint, but it can also represent a group of other FreeGroups. Each FreeGroup has 1 canonical link, whose frame is used for getting and setting properties like pose and velocity. If the FreeGroup is a single tree of connected links, the canonical link should be the root of that tree. If the FreeGroup contains multiple FreeGroups, the canonical link should be selected from one of the component FreeGroups. More...

class  SetFreeGroupWorldVelocity::Implementation< PolicyT >

class  SetFreeGroupWorldPose::Implementation< PolicyT >

class  SetFreeGroupWorldPose
This features sets the FreeGroup pose in world frame. However, while a physics engine with maximal coordinates can provide Link::SetWorldPose and similar functions for setting velocity regardless of the kinematic constraints on that link, this behavior for FreeGroup is not well defined and difficult to implement with generalized coordinates. The FreeGroup::SetWorldPose function should provide an analog to both Link::SetWorldPose and Model::SetWorldPose. More...

class  SetFreeGroupWorldVelocity
This features sets the FreeGroup linear and angular velocity in world frame. More...

## Namespaces

ignition

ignition::physics