CS1400-Semester-Project (Physics Simulation)

Semester Project for CS1400

This project is a highly configurable physics engine that can take a JSON config file and construct an environment with both static and dynamic forces.

How to run:

1. Head over to releases

2. Download the latest release .jar file

3. Run with the following command

java -jar PhysSim.1.0.jar

This will launch a window for a simple projectile motion demo.

If you want to access the dynamic environments, you can add the following argument:

-env:projectile.json

Currently, there are two examples built into the program, projectile.json and orbit.json

You can make your own environment configs and run it similarly by having the jar and JSON files in the same folder.

JSON File Structure:

{ } The root tag
 | - [ ] constants: A list of constants that can be used in the forces
 |    | - ( ) name: The name of the constant, use the name in force strings
 |    ∟ - ( ) value: The value of the constant
 ∟ - [ ] objects: A list of objects in the environment
      | - ( ) name: The name of the object
      | - { } initial_values: The initial values of the object
      |    | - ( ) mass: The mass of the object
      |    | - [ ] position: A list of floats representing a 3D position
      |    |    | - ( ) x: The x position component
      |    |    | - ( ) y: The y position component
      |    |    ∟ - ( ) z: The z position component
      |    ∟ - [ ] velocity: A list of floats representing a 3D velocity
      |         | - ( ) x: The x velocity component
      |         | - ( ) y: The y velocity component
      |         ∟ - ( ) z: The z velocity component
      ∟ - [ ] forces: A list of forces acting on the object
           | - ( ) name: The name of the force
           ∟ - [ ] force: A list of floats or strings representing a 3D force
                | - ( ) x: The x force component (Can be a float or a string)
                | - ( ) y: The y force component (Can be a float or a string)
                ∟ - ( ) z: The z force component (Can be a float or a string)

Example:

Below is a simple projectile motion simulation of an object with a mass of 5kg, initial velocity of (20, 40, 0) m/s, and a gravitational force acting on it proportional to its mass.

{
  "constants": [
    {
      "name": "g",
      "value": -9.81
    }
  ],
  "objects": [
    {
      "name": "projectile",
      "initial_values": {
        "mass": 5,
        "position": [0, 0, 0],
        "velocity": [20, 40, 0]
      },
      "forces": [
        {
          "name": "gravity",
          "force": [0, "g * projectile.mass", 0]
        }
      ]
    }
  ]
}