private void createBody(World world, View view) { BodyDef bodyDef = new BodyDef(); bodyDef.setType(BodyType.DYNAMIC); bodyDef.position.set(pixelsToMeters(view.getX() + view.getWidth() / 2) , pixelsToMeters(view.getY() + view.getHeight() / 2)); Shape shape = null; Boolean isCircle = (Boolean) view.getTag(R.id.mobike_view_circle_tag); if(isCircle != null && isCircle){ shape = createCircleShape(view); }else{ shape = createPolygonShape(view); } FixtureDef fixture = new FixtureDef(); fixture.setShape(shape); fixture.friction = friction; fixture.restitution = restitution; fixture.density = density; Body body = world.createBody(bodyDef); body.createFixture(fixture); view.setTag(R.id.mobike_body_tag,body); body.setLinearVelocity(new Vec2(random.nextFloat(),random.nextFloat())); }