bd.position = new Vec2(cx, cy);
bd.fixedRotation = true;
bd.type = BodyType.DYNAMIC;
Body b = getWorld().createBody(bd);
b.createFixture(fd).setUserData(LIQUID_INT);
MassData md = new MassData();
md.mass = massPerParticle;
md.I = 1.0f;
b.setMassData(md);
b.setSleepingAllowed(false);
liquid[i] = b;