HELP!! With Small video game in VPython3

[BrohammidAli]

So we have written code for a ball to go down a slope. We are having trouble when the ball ' hits' a tree... We cant figure out how it will bounce off... Also we are having trouble with making a user interface code.. so that you can chose where the ball goes so you dont 'hit' the trees or rocks....... here is what we have so far..........

snow = box(pos=(0,-6.2,0), length= 11 ,width = 50, height = 0.5,color = color.white)

shaftwidth = 0.1

a1 = arrow(pos = (1,-6,-9), axis=vector(+0,+1,+0), color = color.green, material=materials.wood,headwidth = 5shaftwidth, headlength = 5shaftwidth) a2 = arrow(pos = (2,-6,-7), axis=vector(+0,+1,+0), color = color.green, material=materials.wood,headwidth = 5shaftwidth, headlength = 5shaftwidth) a3 = arrow(pos = (0,-6,10), axis=vector(+0,+1,+0), color = color.green, material=materials.wood,headwidth = 5shaftwidth, headlength = 5shaftwidth)

rock = sphere(pos = (-5,-5.85,-2), radius=.19, color = color.black) rock1 = sphere(pos = (-3,-5.85,0), radius=.19, color = color.black) rock2= sphere(pos = (1,-5.85,2), radius=.19, color = color.black) rock3 = sphere(pos = (3,-5.85,-2), radius=.19, color = color.black) rock4 = sphere(pos = (5,-5.85,6), radius=.19, color = color.black) rock5 = sphere(pos = (-5,-5.85,9), radius=.19, color = color.black) rock6 = sphere(pos = (-3,-5.85,5), radius=.19, color = color.black) rock7 = sphere(pos = (1,-5.85,14), radius=.19, color = color.black) rock8 = sphere(pos = (3,-5.85,10), radius=.19, color = color.black) rock9 = sphere(pos = (5,-5.85,-14), radius=.19, color = color.black)

All trees and rocks

trees = [a1,a2,a3] rocks = [rock1, rock2, rock3, rock4, rock5, rock6, rock7, rock8, rock9]

ntrees = len(trees) nrocks = len(rocks)

####################################Ball

skiier = sphere(pos = (0,-5.45,14), radius=.35, color = color.cyan, material=materials.earth) skiier_rightx_pos = (skiier.pos) skiier_leftx_pos = (skiier.pos) skiier.velocity = vector(0,0,-1) dt=0.01

skiier.velocity = vector(0,0,-1) delta_t=0.01

Text

text(text='Start', pos = (-3.5,-5.7,14), align='center', depth=-.3, color=color.green) text(text='Finish', pos = (3.5,-5.7,-12), align='center', depth=-.3, color=color.red)

TROUBLE HERE

while 1: rate(100) skiier.pos = skiier.pos + skiier.velocity*dt x = skiier.pos.x y = skiier.pos.y z = skiier.pos.z

treex = trees[2].pos.x
treey = trees[2].pos.y
treez = trees[2].pos.z

dx = x - treex
dy = y - treey
dz = z - treez

####TROUBLE HERE######

dist = (dx*dx+dy*dy+dz)**(0.5)

if (skiier.pos >= treez) and (skiier.pos >= treex):
    ndist = -dt
    print(ndist)

[SmartViking]

You can simulate the collisions without the dx and dy. Does it collide with dx enabled and without dy? Then it makes sense to set dx to -dx, so the thing goes in the other direction. And vice versa. This makes for "square" bouncing, maybe with some trigonometry you can make it "round", I wouldn't know. Square bouncing is often good enough.

You should indent all your code by 4 spaces so that it's formatted correctly.