Square with diagonal lines that interact with each other in one point.
A diagonal line inside of the square divides it in two equal diagonal parts. Inside of the diagonal section are diagonal lines drawn with equal distances on the height with same distance on the width. On the other end interact all lines in the same point. This makes the square looks like it is open and shows at the same time like it would have depth inside of it.
function setup() {
var canvas = createCanvas(500, 500);
canvas.parent('sketch');
background(255);
stroke(1);
noFill();
smooth();
rect(200,200,100,100);
var y = 200;
while (y < 300){
line(300, 200, 200, y);
y += 5;
}
}
function draw() {
}