vp balls

vpballs.py

import random
import vpython as vp

class Game:
    size = 20

class Ball(vp.sphere):
    def __init__(self):
        p  = vp.vector(random.uniform(0, Game.size),
                       random.uniform(0, Game.size),
                       random.uniform(0, Game.size))
        c = vp.vector(random.random(),
                      random.random(),
                      random.random())
        r = random.uniform(0.1, 1)
        super().__init__(pos=p, color=c, radius=r)
        self.speed = random.uniform(0.1, 15)
        self.move = vp.vector(random.uniform(-1,1),
                         random.uniform(-1,1),
                         random.uniform(-1,1))
    
    def update(self, dt):
        self.pos += self.move * dt * self.speed
        if self.pos.x < 0:
            self.pos.x = 0
            self.move.x *= -1
        if self.pos.y < 0:
            self.pos.y = 0
            self.move.y *= -1
        if self.pos.z < 0:
            self.pos.z = 0
            self.move.z *= -1
        if self.pos.x > Game.size:
            self.pos.x = Game.size
            self.move.x *= 1
        if self.pos.y > Game.size:
            self.pos.y = Game.size
            self.move.y *= 1
        if self.pos.z > Game.size:
            self.pos.z = Game.size
            self.move.z *= 1

balls = []
for _ in range(10):
    balls.append(Ball())

while True:
    vp.rate(60)
    for b in balls:
        b.update(1/60)