Revolve aims to be a flexible robot evolution framework, providing C++ and Python libraries to create, simulate and manage robots in the Gazebo robot simulator.

The most elaborate component of Revolve is the robot body framework. It is heavily inspired by the robot structure als employed by Robogen. The framework works by specifying a body space using a revolve.spec.BodyImplementation. This boils down to specifying a number of predefined body parts, each of which defines a number of inputs (i.e. sensors), outputs (i.e. motors) and attachment slots, which are locations where other body parts connect. Parts can also specify any number of configurable numeric parameters. A body part is physically represented by a subclass of the revolve.build.sdf.BodyPart class, and can in turn consist of many components that give the part its physical behavior. These components are specified using the classes in the sdfbuilder library, which is a thin convenience wrapper over SDF itself (direct XML can also be used with little effort).

Given a specification, a robot body can be constructed by Revolve from a revolve.spec.msgs.Body class, which is specified in Google Protobuf for flexibility. This class specifies a tree structure, starting with a root node extending to other body parts through its attachment slots. A revolve.build.sdf.BodyBuilder class is capable of turning a combination of such a robot and a body specification into an SDF file that can be directly used in Gazebo.

Revolve also ships with some simple generator classes, which can generate arbitrary robot bodies from scratch given a set of constraints.

For the details, see wiki pages.