1. Create a folder /lib/
2. Right Click on /lib, select Import
3. Select General / File System
4. Choose the directory of jbox2d.jar
5. Import the file jbox2d.jar
6. Right click on the project and select “Properties”
7. Click on “Java Build Path” and select the “Libraries” tab
8. Click on “Add JARs…” and pick the file jbox2d.jar

It is important to keep two things in mind:

• Axis orientations: the coordinate (0, 0) with the G1 is typically the upper left corner of the screen, while (0, 0) in Box2D is the bottom left corner of the screen.
• The other thing are dimensions: Box2D works fine with dimensions from 0.1 to 10 times the typical earth dimensions such as density, friction, gravity, …. Internally the engine is using meters and we will need to convert them to pixels. If we say, 1 meter shall be 10 pixels, that function could look like this: