from visual import *
ball = sphere(pos=(-5,0,0), radius = 0.5, color=color.cyan)
wallR = box(pos=(6,0,0),size=(0.2, 12, 12), color=color.green)
wallL = box(pos=(-6,0,0),size=(0.2, 12, 12), color=color.green)
wallU = box(pos=(0,6,0),size=(12, 0.2, 12), color=color.red)
wallD = box(pos=(0,-6,0),size=(12,0.2, 12), color=color.red)
wallF = box(pos=(0,0,-6),size=(12,12,0.2), color=color.white)
ball.velocity=vector(20,5,-7)
vscale=0.1
varr = arrow(pos=ball.pos, axis=ball.velocity*vscale, color = color.yellow)
ball.trail = curve(color = ball.color)
deltat=0.005
t=0
scene.autoscale = False
while True:
    rate(100)
    if ball.pos.x > wallR.pos.x or ball.pos.x < wallL.pos.x:
        ball.velocity.x = -ball.velocity.x
    if ball.pos.y > wallU.pos.y or ball.pos.y < wallD.pos.y:
        ball.velocity.y = -ball.velocity.y
    if ball.pos.z > 6 or ball.pos.z < wallF.pos.z:
        ball.velocity.z = -ball.velocity.z    
    ball.pos = ball.pos + ball.velocity*deltat
    ball.trail.append(pos=ball.pos)
    t = t + deltat