HW 3: Solar System
PAT 204/504: Creative Coding (Fall 2025)
Due at 11:59pm ET on September 29
Instructions
- Please submit both your code and your final rendering. You will receive zero credit if the code is missing.
- All assignments must be completed on your own. You are welcome to exchange ideas with your peers, but this should be in the form of concepts and discussion, not in the form of writing and code.
- Provide proper citations/references for any external resources you use in your writing and code.
- Submit your work to Gradescope.
- Late submissions will be accepted for up to a week with 1 point deducted per day.
Q1: Sun, Earth, and Moon (2 points)
Let’s build a sun-earth-moon system! You’re provided a template sketch below, which will render a simple sun-earth model:
Now, your task is to add the moon! The moon should rotate around the earth:
Template Sketch for Q1
boolean saveFrames = false;
float theta = 0;
float radius = 120;
float speed = 0.02;
color c = #93E8FF;
float x, y;
void setup() {
// Create a 400x400 canvas
size(400, 400);
// Set a all-black background
background(0);
// Set the frame rate to 30 fps
frameRate(30);
}
void draw() {
// Fading effect
noStroke();
fill(0, 100);
rect(0, 0, height, width);
// Sun
fill(#FFCC00);
circle(200, 200, 20);
// Earth
theta -= speed;
x = cos(theta) * radius + 200;
y = sin(theta) * radius + 200;
fill(c);
circle(x, y, 10);
// Save the current for making a GIF
if (saveFrames) {
saveFrame("frames/###.png");
}
}
Q2: Solar System (3 points)
Let’s build a solar system! You’re provided a template sketch along with a template for the Star class (“Star.pde”). Now, your task is to complete the template sketch and implement a solar system with 5+ planets.
Feel free to design your solar system with any color palette and speed/radius combination you like. Note that each planet must start from a random angle, which you should initialize in the constructor function of the Star class.
Template Sketch for Q2
boolean saveFrames = false;
Star[] stars = new Star[1];
void setup() {
// Create a 400x400 canvas
size(400, 400);
// Set a all-black background
background(#142034);
// Set the frame rate to 30 fps
frameRate(30);
// Initialize the stars
stars[0] = new Star(30, 0.18, #edafb8);
// YOUR CODE HERE
}
void draw() {
// Fading effect
noStroke();
fill(#142034, 50);
rect(0, 0, height, width);
// Sun
fill(#eebb00);
circle(200, 200, 10);
// Iterate over the stars
for (Star star: stars) {
// Update the star position
star.update();
// Show the star
star.show();
}
// Save the current for making a GIF
if (saveFrames) {
saveFrame("frames/###.png");
}
}
Template Star Class
// Star.pde
class Star {
float radius;
float speed;
color c;
float theta;
float x, y;
// Constructor
Star( /* YOUR CODE HERE */ ) {
// YOUR CODE HERE
}
// Show the star
void show() {
// YOUR CODE HERE
}
// Update the star position
void update() {
// YOUR CODE HERE
}
}