Week 3 | I’ve come to bargain!

Check out the sketch here!

Concept & Inspiration

This weekend, a lot of things happened. Because some unfortunate things happened, I decided to re-watch a few Marvel movies. After this I got an inspiration for Week 3’s assignment to create an eye that looks like Dormamu’s, the main antagonist of Doctor Strange.

Sketch

How it works

A particle class called Particle takes a few arguments (position, velocity, color). Overall, the class defines the behavior of a particle in the sketch. It contains a display() method that checks whether the particle is in a certain position, within a certain distance from the attractor, and whether it should be reflected or not. The particle’s path is visualized as a line between its current and previous positions.

class Particle {
  constructor(pos, v, color) {
    this.pos = pos; //Current Position
    this.pos_before = pos; //Previous Position
    this.v = v; //Velocity
    this.a = createVector(0, 0); //Acceleration, starting at 0,0
    this.color = color; //Color
  }
display() {
push();
stroke(this.color.x, this.color.y, this.color.z); //Stroke color based on XYZ
line(this.pos.x, this.pos.y, this.pos_before.x, this.pos_before.y); //Line from current to prev. pos this gives a trail effect.
pop();

If a particle comes into contact with an attractor (the one in the middle), a reflection occurs:

1. The particle is moved to the surface of the attractor by adjusting its position vector.
2. The velocity vector is  (multiplied by -1), and the particle is slightly rotated to simulate a reflection angle.
3. The velocity is also scaled down by multiplying 0.9 to simulate some loss of energy upon reflection.

The main sketch sets up the canvas, initializes particles, and controls their movement under the influence of gravity and collision dynamics. A central attractor is created as a rotating ring of gravitational points. Particles are randomly spawned outside the central attractor and move according to gravitational forces. Each particle reacts to the gravitational field by accelerating toward attractor points, and each particle can reflect off the surfaces of attractors if they collide.

Challenges and things to improve

I wanted to create a particle simulation that does not rely on particle systems. As an alternative, I relied mostly on arrays. Due to this, some calculations required me to deep dive into a bit of mathematics more than I initially planned. Also, initially, I wanted to make two eyes, but having two attractors provided to break the entire simulation, perhaps part of n-body problem characteristics. Thus, I did not want to go further into that concept.

Resources Used

Mutual Attraction – Daniel Shiffman

Inverse Square Law – Derek Owens

angleBetween – p5.js

rotate – p5.js