Object

class eagerx.core.entities.Object

Baseclass for objects.

Use this baseclass to implement objets that consist of sensors, actuators, and/or engine states.

Users must call make() to make the object subclass’ specification.

Subclasses must implement the following methods:

• make()

For every supported Engine, an implementation method must be added. This method must have the same signature as example_engine():

• pybullet() (example)

• ode_engine() (example)

• …

example_engine(spec, graph)

An example of an engine-specific implementation of an object’s registered sensors, actuators, and/or states.

See engine how engine specific parameters can be set/get.

This method must be decorated with eagerx.core.register.engine() to register the engine implementation of the object.

Note

This is an example method for documentation purposes only.

Parameters:

• spec (ObjectSpec) – A (mutable) specification.

• graph (EngineGraph) – A graph containing the object’s registered (disconnected) sensors & actuators. Users should add nodes that inherit from EngineNode, and connect them to the sensors & actuators. As such, the engine nodes become the engine-specific implementation of the agnostic sensors & actuator definition.

Return type:

None

classmethod info(method=None)

A helper method to get info on a method of the specified subclass.

Parameters:

method (Union[List[str], str, None]) – The registered method we would like to receive info on. If no method is specified, it provides info on the class itself.

Return type:

str

Returns:

Info on the subclass’ method.

abstract classmethod make(*args, **kwargs)

An abstract method that makes the specification (also referred to as spec) of this object.

See ObjectSpec how sensor/actuator/engine state parameters can be set.

This method should be decorated with:

• eagerx.core.register.sensors() to register sensors.

• eagerx.core.register.actuators() to register actuators.

• eagerx.core.register.engine_states() to register engine states.

Parameters:

• args (Any) – Arguments to the subclass’ make function.

• kwargs (Any) – Optional Arguments to the subclass’ make function.

Returns:

A (mutable) spec that can be used to build and subsequently initialize the entity (e.g. node, object, …).