PolygonShape polygonShape = new PolygonShape();
polygonShape.setAsBox(1.1f, 1.1f);
polygonShape.m_radius = 1;
FixtureDef fixtureDef = new FixtureDef();
fixtureDef.shape = polygonShape;
fixtureDef.density = 1;
fixtureDef.friction = 0;
fixtureDef.restitution = 0;
fixtureDef.filter.categoryBits = category;