For the final MP, in an effort to allow you room for some creativity, you have a choice of two possible assignements:

1.  Create a 3D Particle System
   
   Write a simple particle system using WebGL to handle the display. Particle systems are typically used to model fine-grained physical effects like fire, smoke, and water.
   ​We will do something simpler and just render a system of bouncing spheres in 3D. The specifics of how you implement the following features are up to you...write an app that you think is fun...
   1. Your program will render a set of spheres bouncing around an invisible (or visible if you wish...) 3D box. You could use a box with corners (-1,-1,-1) to (1,1,1) for example.
      When a sphere hits one of the walls in the box, it should reflect in physically realistic manner.  
   2. You should keep an array or list of particles. Each particle will have a postion P and velocity V. Both of these quantities will be three-dimensional quantities.
      1. It is acceptable to render all the spheres with a uniform radius and color, however...
      2. ...you can include other attributes if you like. For example, you could have each sphere have an individual color or radius or alpha value....
   3. You only need to generate one sphere mesh...you simply draw that mesh in multiple different spots each frame.
      1. You can use some of the code from the HelloSolarSystem3.html demo that is one the course website....grab the code to generate and draw a sphere.
   4. Your user interface should allow you to create spheres using a mouse click or key press. Each creation event should create X spheres, where X is some number of your choosing.
      1. The spheres should be genereated with a random position and velocity. You will need to bound those values to be reasonable (e.g. position inside the box).
      2. You will also need a reset button that will remove all existing spheres from the scene.
   5. After rendering a frame showing the current position of the spheres, you will need to update the position and velocity of each sphere.
      1. Update the position using the current velocity and Euler Integration
      2. Update the velocity using the set of forces you are implementing (e.g. gravity and friction) 
   6. Implement 2 forces that affect the spheres: gravity and friction. If you want to violate physics for funand have the spheres gain velocity after hitting walls, you can do that as well. 
       
2. Turn your Terrain Code into a 3D Game
   
   ​Write a simple 3D game in which you fly around your terrain and try to collect spheres that fall from the sky. The spheres are dropped from random positions. They need not go straight-down...
   they can have more complicated initial velocities, but should fall in accordance with a gravitational force.
   1. You should implement at least 2 types of spheres:
      1. Ones that you colllect, which are designated by being a certain color
      2. Ones that causes you to lose all your collected spheres if it hits you. Again, use color to designate these spheres
   2. The spheres should fall in accodance with a gravitational force
   3. When spheres reach a certain altitude they should disappear
   4. Keep track of the number of spheres collected and display that number
   5. Perform collision detection between your plane (the eyepoint) and spheres...you collect spheres by colliding with them
   6. You can add any other features you like to.... ​​

You will upload your files to compass in a zipped folder with name ${NetID}_MP4.zip. Include all of the files necessary for your application to run locally. Name your webpage Spheres.html

Rubric:

Feature	Points	Description
Interactive UI	1pt	Implement the UI functionality described above
Phong or Blinn-Phong Shading	1pt	Make sure the scene is well-lit. You can use the same Phong or Blinn-Phong shaders you used in previous MPs
Forces	2pt	Implement the required forces
Euler Integration	2pts	Use Euler Integration to compute new particle positions
Sphere Collision Detection	2pts	Correctly test for the required sphere collisons
Documentation	1pt	Have your webpage explain the program interface
Comment your code	1pt	Comment your code