6.837 - Project #5

Ground Rules for all projects:
In this last project you are asked to make two changes to the ray tracer given in class.
  1. Add refraction to the illumination model.
    • Refraction is discussed in Hearns & Baker pp. 530-531
    • The last two parameters of the surface model kt and nt should be interpreted as follows; kt is the fraction of the transmitted ray's intensity that is reflected to the eye, nt is the ratio of the surrounding material's index of refraction to the object's index of refraction. For example, if you want to simulate a spherical water drop the index of refraction for water is approximately 1.33. If we assume the surrounding material is air then its index of refraction is 1. So when a ray strikes the outside of the object the term used in the equation given in the book is computed as follows.

      And when a ray inside of an object exits it then the term used in the book is computed as follows.
      Note: The Object shader tells the Surface shader whether the ray is entering or exiting the object with its "inside" flag
    • You don't have to explicitly compute angles and their cosines as shown in the book. You can use various dot products to get these values.


  2. Add your own primitive. For example
    • cone tipX tipY tipZ baseX baseY baseZ baseRadius
    • cylinder topX topY topZ baseX baseY baseZ Radius
    • torus centerX centerY centerZ orbitX orbitY orbitZ Radius
    • triangle aX aY aZ bX bY bZ cX cY cZ
    • others
  3. You may optionally do any of the following
    • Add more primitives
    • Incorporate bounding volumes or spatial subdivision
You should start with this version of the code. When you turn in you project I expect to see an exmple applet and a new scene file that displays transparency as well as your new primitive.