Project 07 – Yugyeong Lee

sketch

//Yugyeong Lee
//Section B
//yugyeonl@andrew.cmu.edu
//Project-07

var nPointsA= 600;
var nPointsB= 200;
var nPointsC= 800;
var x;
var y;
var constrainX;

function setup() {
    createCanvas(480, 480);
}

function draw() {
	//ghosted background changing color based on mouseX
	var constrainX = constrain(mouseX, 0, width); //constraining mouseX in the page
	var r = map(constrainX, 0, width, 100, 39);
	var g = map(constrainX, 0, width, 43, 15);
	var b = map(constrainX, 0, width, 107, 54);
    background(r, g, b, 40);
    //Hypotrochoid & Ellipse
    push();
    translate(width/2, height/2);
    drawHypotrochoid();
    drawEllipse();
    pop();
    //Ranunculoid (only appears if mouseX is on left three quarter of page)
    if (constrainX < 3*width/4) {
   		push();
    	translate(width/2, height/2);
    	//mapping the angle of rotation based on mouseX
    	var angle = map(constrainX, 0, width, 0, 4 * TWO_PI);
		rotate(angle);
    	drawRanunculoid();
    	pop();
    }
}

function drawHypotrochoid() {
    constrainX = constrain(mouseX, 0, width); //constraining mouseX in the page
	var n = map(constrainX, 0, width, 0, .5);
    var a = 225;
    var b = n*a;
    var h = constrain(mouseY/2, 0, b);

    noFill();
    //change strokeWeight based on mouseX
    var s = map(constrainX, 0, width, .1, 2);
    //change stroke color based on mouseX
    var c = map(constrainX, 0, width, 255, 100);
    stroke(c)
    strokeWeight(s);
	beginShape()
		for (var i = 0; i < nPointsA; i++) {
			var t = map(i, 0, nPointsA, 0, 6*TWO_PI);
			x = (a - b)*cos(t) + h*cos((a - b)/b*t);
			y = (a-b)*sin(t) + h*sin((a-b)/b*t);
			vertex(x, y);
		}
	endShape(CLOSE);
 }

 function drawRanunculoid() {
    constrainX = constrain(mouseX, 0, width); //constraining mouseX in the page
    var a = 30;
    noStroke();
    //change fill oppacity based on mouseX
    var opacity = map(constrainX, 0, width, 10, 50);
    fill(255, 255, 255, opacity);
	beginShape()
		for (var i = 0; i < nPointsB; i++) {
			var t = map(i, 0, nPointsB, 0, TWO_PI);
			x = a*(6*cos(t)-cos(6*t));
			y = a*(6*sin(t)-sin(6*t));
        	ellipse(x, y, 5, 5); //ellipse at each points
		}
	endShape(CLOSE);
 }

function drawEllipse() {
    constrainX = constrain(mouseX, 0, width); //constraining mouseX in the page
    var a = 270;
    var b = 270;
    noFill();
	beginShape()
		for (var i = 0; i < nPointsC; i++) {
			var t = map(i, 0, nPointsC, 0, 6*TWO_PI);
			x = a*cos(t);
			y = b*sin(t);
			//ellipse at random position x and y range
        	ellipse(x+random(-50, 50), y+random(-50, 50), 3, 3);
		}
	endShape(CLOSE);
 }

I used three different curves for this interactive design: hypotrochoid, ranunculoid, and ellipse. The final product is interactive in that not only does the design react to position Y of the mouse location, the curves, the angle it rotates, stroke weight, stroke color, stroke opacity and background color all react to position X of the mouse location. Because of the circular movement of the other two curves, I wanted to create a “night-sky-with-blinking-stars” effect through creating an ellipse in which points are randomly positioned within a limited range with white blinking circles. The color palette was also chose to reflect the night sky atmosphere.

how Hypotrochoid & Ranunculoid works