Bullet class is a 3D collision detection and physics library that is similar to Box2D (http://bulletphysics.org/mediawiki-1.5.8/index.php/Main_Page). LibGDX has a wrapper for
Bullet, but it has a steep learning curve due to the JavaCPP bridge. Please check out the official
Bullet manual at https://github.com/erwincoumans/bullet2/blob/master/Bullet_User_Manual.pdf?raw=true. The
Bullet package is an extension and needs to be added manually. Follow the same process that you followed for Box2D with the following details, and refresh the Gradle dependencies.
compile "com.badlogicgames.gdx:gdx-bullet-platform:$gdxVersion:natives-desktop" ...