CS594 Computer Graphics Lab 2

Objectives

• To expand your software with new functions with well thought out designs and high quality implementation.
• To understand and implement ambient, diffuse and specular lighting conditions and flat/smooth shading.
• To understand and implement basic polygon texture mapping techniques.
• To understand and implement environment mapping.
• To understand and be able to use pixel data functionality of OpenGL.
• To understand at least one image format, and be able to read such formatted images.

Assignment Description

The basic steps you will go through in this lab include:

• Obtain per-vertex normal by computing cross products. Make sure that all the normals across the triangle mesh are pointing outwards. (How do you find out and store the neighborhood information?)
• Implement ambient, diffuse and specular components with glMaterial class function calls. A table of known material properties of a range of material types, from brass to copper, gold, emerald, jade and rubber, have been provided under the class directory (~huangj/CS594F08/materials_ogl.htm)
• Implement smooth shading.
• Understand at least one image format, suggested formats are *.rgb, *.bmp and *.targ. Implement your own routine to load images from disk into memory for texture mapping purposes. (please look under class directory: ~huangj/CS594F08/RGBfiles)
• Use a simple cube of unit size.  Do a basic polygon texture map on all 6 faces with any image you would like to use. (How would you store the texture coordinates?)
• Use a simple sphere, map a global map onto the sphere. Please try to use both color and opacity channels to create an earth model with the continents being opaque (alpha = 1.0) and the oceans being none opaque (alpha < 1.0).
• Understand and implement environment mapping with OpenGL automatic texture coordinate generation functions.
• Implement cubic environment mapping without using OpenGL automatic texture coordinate generation function, but instead, try to generate your texture coordinates.
• Use procedural texture to apply solid texturing of marble to any model of your choice (better with object in sculpture flavors) (Where would you store 3D texture coordinates?) The related source code is located under ~huangj/CS594F08/Marble. You should first use the given function to compute a 3D texture and load that into memory (page 372, red book, ed 1.2). And then use 3D texture coordinates to performance the texture mapping.

Extra credit

Try to arrange a scene with the models that you have access to. (We will talk about scene graph in the later half of the semester. But with not too many object, it is doable without using scene graphs.)

• Create a scene where a Buddha or a sculpture is standing in front of a mirror in a room with texture mapped floor. 30%
• Create a solar system filled with texture mapped earths.(yes, 9 earths around the sun). 10%
• Anything else you would like to do. Please run it by me before you do it, so that I have an idea how much extra credit I would be giving out.

Deadline

Tuesday, October 14, 2008

Detailed Lab Setup Information

Please consult TA's

Suggested Strategy

The assignment description is meant as a brief guidance of what steps you need to go through. It is highly desirable for you to have a big picture and seriously spend a couple hours designing your software, and think about the trade off that you would face,  BEFORE you actually go implement anything.  You should not only consider performance, readability, maintainability but also possibilities for further development of new functions as key issues in your design.  This would end up saving you a lot of time later on, because of less number of patches you have in your code and a much more efficient debugging process in result.

During your implementation, an incremental way of development is always helpful with debugging too. As usual, it is strongly suggested that you start early on this lab. There are a lot of stuff involved in this lab.

Happy rendering!