Tag Archives: illusion

Bulge Illusion with Python Turtle (Source Code Included)

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This is another Akiyoshi illusion. It feels like the center is bulging.

Bulge Illusion

Source Code:

import turtle

screen = turtle.Screen()
screen.setup(800,800)
screen.setworldcoordinates(-8,-8,8,8)
screen.tracer(0,0)
screen.title('Bulge Illusion - PythonTurtle.Academy')
turtle.hideturtle()
turtle.speed(0)

color1 = 'light sky blue'
color2 = 'firebrick'
screen.bgcolor(color2)

def draw_square(x,y,size,c):
    turtle.up()
    turtle.goto(x-size/2,y-size/2)
    turtle.seth(0)
    turtle.color(c)
    turtle.begin_fill()
    for _ in range(4):
        turtle.fd(size)
        turtle.left(90)
    turtle.end_fill()
    
def draw_board():
    for x in range(-7,8,2):
        for y in range(-7,8,2):
            draw_square(x,y,1,color1)
    for x in range(-6,8,2):
        for y in range(-6,8,2):
            draw_square(x,y,1,color1)
            

def draw_diag(x,y):
    c = color2 if (x+y)%2 == 0 else color1
    if x*y > 0:
        draw_square(x-0.3,y+0.3,0.3,c)
        draw_square(x+0.3,y-0.3,0.3,c)
    elif x*y < 0:
        draw_square(x+0.3,y+0.3,0.3,c)
        draw_square(x-0.3,y-0.3,0.3,c)

def draw_straight(x,y):
    c = color2 if (x+y)%2 == 0 else color1
    if y>0:
        draw_square(x-0.3,y-0.3,0.3,c)
        draw_square(x+0.3,y-0.3,0.3,c)
    elif y<0:
        draw_square(x-0.3,y+0.3,0.3,c)
        draw_square(x+0.3,y+0.3,0.3,c)
    elif x>0:
        draw_square(x-0.3,y-0.3,0.3,c)
        draw_square(x-0.3,y+0.3,0.3,c)
    elif x<0:
        draw_square(x+0.3,y-0.3,0.3,c)
        draw_square(x+0.3,y+0.3,0.3,c)
        
def draw_bulge():
    for x in range(-6,7):
        for y in range(-6,7):
            if abs(x)+abs(y)<=7:
                draw_diag(x,y)
                if x==0 or y==0: draw_straight(x,y)
    x,y = -5,-3
    for i in range(3):
        draw_diag(x,y)
        draw_diag(-x,-y)
        draw_diag(x,-y)
        draw_diag(-x,y)
        x += 1
        y -= 1
draw_board()
draw_bulge()
screen.update()

Rolling Illusion with Python Turtle (Source Code Included)

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Akiyoshi made this original rolling illusion. It feels like the cylinders are rolling. You may want to how to draw oval or ellipse for this project.

Rolling Illusion with Python Turtle

Source code:

import turtle
import math

screen = turtle.Screen()
screen.setup(1100,1000)
screen.setworldcoordinates(-620,-550,680,550)
screen.tracer(0,0)
screen.title('Roller Illusion - PythonTurtle.Academy')
turtle.hideturtle()
turtle.speed(0)
n=100
# parametric equation to draw ellipses
def ellipse(cx,cy,a,b,c1,c2,c3):
    t = -math.pi/2
    x = cx+a*math.cos(t)
    y = cy+b*math.sin(t)
    turtle.up()
    turtle.goto(x,y)
    turtle.down()
    turtle.pencolor(c1)
    turtle.fillcolor(c3)
    turtle.begin_fill()
    for i in range(n//2):
        x = cx+a*math.cos(t)
        y = cy+b*math.sin(t)
        turtle.goto(x,y)    
        t += 2*math.pi/n
    turtle.pencolor(c2)
    for i in range(n//2):
        x = cx+a*math.cos(t)
        y = cy+b*math.sin(t)
        turtle.goto(x,y)    
        t += 2*math.pi/n
    turtle.end_fill()

def rolling_column(x,size):
    for y in range(-400,500,100):
        ellipse(x,y,size,35,'white','black','dark orange')
        
def rolling_column2(x,size):
    for y in range(-400,500,100):
        ellipse(x,y,size,35,'black','white','dark orange')

def rolling():
    rolling_column(-450,10)
    rolling_column(-410,13)
    rolling_column(-360,16)
    rolling_column(-300,19)
    rolling_column(-240,16)
    rolling_column(-190,13)
    rolling_column(-150,10)

    rolling_column2(-130,10)
    rolling_column2(-90,13)
    rolling_column2(-40,16)
    rolling_column2(20,19)
    rolling_column2(80,16)
    rolling_column2(130,13)
    rolling_column2(170,10)

    rolling_column(190,10)
    rolling_column(230,13)
    rolling_column(280,16)
    rolling_column(340,19)
    rolling_column(400,16)
    rolling_column(450,13)
    rolling_column(490,10)
    
turtle.color('steel blue')
turtle.up()
turtle.goto(-1000,-1000)
turtle.down()
turtle.begin_fill()
turtle.seth(0)
for _ in range(4):
    turtle.fd(2000)
    turtle.left(90)
turtle.end_fill()
turtle.pensize(3)
rolling()
screen.update()
# the following generates high quality image
filename="rolling_illusion.eps" 
ts = turtle.getscreen()
ts.getcanvas().postscript(file=filename)