Jisoo Geum – Project 07 – Curves

sketch

// Jisoo Geum
// Section B
// jgeum@andrew.cmu.edu 
// Project-07
var x;
var y; 
var bR; // big radius outside 
var r; // smaller radius inside 
var d; // distance from the center of the interior circle 
var mx; // mouseX
var my; // mouseY 

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

function draw() {
    background(255,0,0);
    translate(width/2, height/2);
    noFill();
    mx = constrain(mouseX,0, width);
// draw a Hypotrochoid with ellipses 
        strokeWeight(1);
        stroke(255);
        for (var a = 0; a < 2*TWO_PI; a ++){ // a is angle 
            bR = 50; // big radius 
            r = map( mx, 0, width, 10, 65 ); // small radius
            d = map( mx, 0, width, 10, 100 ); // distance 
            x = (bR-r)*cos(a) + d*cos( ((bR-r)/r)*a ) ;
            y = (bR-r)*sin(a) - d*sin( ((bR-r)/r)*a ) ;
        ellipse(0,0,x*5,y*7);
        }

// draw Nephroid
            strokeWeight(0.25);
            stroke(255);
            for (var a = 0; a < 10*TWO_PI; a ++){ // a is angle 
                bR = map( mx, 0, width, 0, 130 ); // big radius  
                x = bR*((3*cos(a)) -  (cos(3*a))) ;
                y = bR*((3*sin(a)) -  (sin(3*a))) ;
            ellipse(0,0,x*30,y*15);
            }

// draw Hypotrochoid 
    beginShape();
        strokeWeight(.75);
        stroke(255);
        for (var a = 0; a < 25*TWO_PI; a ++){ // a is angle 
            bR = 200;   // big radius 
            r = map( mx, 0, width, 10, 130 ); // small radius
            d = map( mx, 0, width, 10, 300 ); // distance 
            x = (bR-r)*cos(a) + d*cos( ((bR-r)/r)*a ) ;
            y = (bR-r)*sin(a) - d*sin( ((bR-r)/r)*a ) ;
        vertex(x,y);
        }
    endShape();

}

I first went to WolframMathworld website too look for shapes that I found interesting. I eventually decided to use the equations for hypotrochoid and nephroid since I thought the combination of roulette and plane curves would make a good contrast.  Although the curves in the final iteration didn’t turn out as I thought, I thought that the shapes were still interesting.

These are the process images before I adjusted the limits in the for loops and the parameters of vertex & shapes. If I could change anything from the final design, I would adjust the map()  more so that the movement would look more organized.