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Hey everyone
I’ve begun to write smth like air hockey and for now stuck cause the ball stays on its place but prints that the position is changing. I can’t figure why, seems i’ve written it just like the paddles that can move

Here’s the code, about a 100 lines

from scene import *
import math
import random


sw, sh = get_screen_size()[0], get_screen_size()[1]


class Ball(SpriteNode):
    def __init__(self, r=11, v=(1, 1), parent=None, *args, **kwargs):
        self.size = (r*2, r*2)
        self.v = Vector2(*v)
        self.r = r
        self.ball_speed = 10
        self.angle = random.uniform(0, 2*math.pi)
        SpriteNode('pzl:BallGray', color='purple', parent=parent, *args, **kwargs)



class Game(Scene):
    def setup(self):
        self.background_color = 'black'
        board_shape = ui.Path.rounded_rect(0, 0, sw-30, sh-30, 15)
        board_shape.line_width = 4
        self.board = ShapeNode(board_shape, position=(sw/2, sh/2), 
                          stroke_color='#723d04', fill_color='#acacac',
                          z_position=-1, parent=self)

        self.left_player = SpriteNode('pzl:PaddleBlue', position=(-420, 0),
                                      parent=self.board)
        self.left_player.rotation = math.pi/2

        self.right_player = SpriteNode('pzl:PaddleRed', position=(420, 0),
                                       parent=self.board)
        self.right_player.rotation = math.pi/2

        self.right_touch, self.left_touch = (0, 0), (0, 0)

        self.spawn_ball()


    def update(self):
        print(self.ball.position)
        x, y = self.ball.position + self.ball.v
        self.ball.position = Point(x, y)


    def touch_began(self, touch):
        touch_loc = self.board.point_from_scene(touch.location)
        if touch_loc in self.left_player.frame:
            self.left_touch = touch.touch_id
        elif touch_loc in self.right_player.frame:
            self.right_touch = touch.touch_id


    def touch_moved(self, touch):
        if self.right_touch != (0, 0) or self.left_touch != (0, 0):
            self.move_paddle(touch)


    def touch_ended(self, touch):
        touch_id = touch.touch_id
        if touch_id == self.right_touch:
            self.right_touch = (0, 0)
        elif touch_id == self.left_touch:
            self.left_touch = (0, 0)


    def move_paddle(self, user_touch):
        paddle = None
        touch_id = user_touch.touch_id
        delta_y = user_touch.location.y - user_touch.prev_location.y
        if touch_id in self.left_touch:
            paddle = self.left_player
        elif touch_id in self.right_touch:
            paddle = self.right_player

        if paddle:  
            x, y = paddle.position
            if delta_y > 0:
                paddle.position = x, min(y + delta_y, sh/2 - 70)
            elif delta_y < 0:
                paddle.position = x, max(y + delta_y, -sh/2 + 70)


    def spawn_ball(self):
        self.ball = Ball(position=(0, 0), parent=self.board)
        self.ball.v = (math.cos(self.ball.angle), math.sin(self.ball.angle))



run(Game())

@Karina, very nice and clear code.

In Ball __init__, you have to call

super().__init__('pzl:BallGray', color='blue', parent=parent, *args, **kwargs)

... on the last line. What you have there now creates and places another SpriteNode, not tied to self.ball at all.

@mikael thanks) why have I overlooked that

Spam above.
by the way, don't forget to present you new hockey game after its release.