CSE681 Lab 1

• We are not going to use OpenInventor this quarter. This is a change from recent previous 681 classes. This will change the labs and class notes.
• Professor Shen has some Lab Help pages that you might find useful. However, note that my lab assignments may or may not be the same as Dr. Shen's - so when he refers to something about a specific lab assignment, you need to relate that to my assignment. (But you'll have to ignore the OpenInventor stuff there).

Objective

Assignment & Requirements

• Call your program lab1.
• Use whatever classes and program organization you want - but the program should be documented and easily 'readable' by the grader.
• You can refer to the book, the web, other books, etc. to see code fragments for the various tasks you'll have to program - but write your own code. Questions concerning code will be on the midterm and final.
• Build a ray tracer that uses a pre-defined camera, intersects a single sphere of radius 10 centered at the origin, shades it according to the normal vector at the intersected point.
• To shade the sphere:
  • At the visible point of intersection, calculate the normal vector (vector from the center of the sphere to the intersection point),
  • normalize the normal vector
  • Use the z component of the normal vector to scale the color of the sphere.
• Default scene consists:
  • background color of (0.0 0.6 0.6)
  • no lights
  • ambient value of 0.2
  • one sphere
    • at (0,0,0)
    • radius of 10
    • color of (0.8 0.2 0.2)
  • camera
    • position at (0.0 0.0 30.0)
    • center-of-interest, or lookat point, of (0.0 0.0 0.0)
    • half angle of view of 45 degrees
    • aspect ratio of 1.0
    • hither and yon distances of 1.0 and 100.0
    • tilt angle of 0.0 degrees
    • resolution of 400 x 400
• When a ray intersects the sphere, compute the intensity of a point on a sphere thusly:
  • compute the normalized normal vector of the point on the sphere
  • set the intensity to the maximum of the ambient value and the z-component of the normal vector
• Write the image of the ray-traced scene out to a portable pixmap file, called output.ppm. In the PPM file, use 255 as the maximum color component.
• Submit the source code for your program. For example:

  submit c681aa lab1 lab1.c makefile
  

  Of course, you can break it up into multiple source files and submit those. For example:

  submit c681aa lab1 main.cpp camera.cpp sphere.cpp light.cpp makefile
  

  - just as long as the grader can make and execute your program, and then find the output in output.ppm:

  make
  lab1