Advanced Programming Techniques - Learning LibGDX Game Development - page 325

Physics body editor
The creation of bodies for images with complex shapes can be a very time-consuming
task. The Physics Body Editor, created by Aurélien Ribon, lets you build bodies in
a graphical editor and comes with many useful features, such as decomposition
of concave shapes into convex polygons, tracing outlines of images, and a built-in
collision tester.
Check out the official project website at https://code.google.com/p/box2d-
editor/ . A screenshot from the project's website that shows the editor in action
is as follows:
Adding Box2D
From LibGDX 1.0.0 onward, Box2D is separated from gdx.jar and moved to a new
extension. However, if you are using the Gradle-based setup tool, you can simply
check the Box2D box and generate your project.