CPSC 102 (CS-2)

Course overview and objectives -

This is the second course offered to incoming computing majors at Clemson University.  Students construct a ray tracing system in a semester long project.  It assumes CPSC 101 as  a pre-requisite.  Instruction is delivered in three lecture hours and one two-hour closed lab per week.   Course objectives  are somewhat wide ranging.

At the conclusion of the course the successful student understand and be able to understand and be able to employ the following concepts in the construction of a non-trivial program consisting of tens of source modules and functions.

• Principles of incremental development and testing, including top down design,  bottom up implementation,  component testing and system testing.

• Using the Unix make system to manage the build process.

• Use of tools and techniques for detecting and correcting errors.

The student should also understand the follow elements of object oriented design and object oriented languages

• The role of inheritance is creating hierarchies of increasing specialization

• The role of polymorphism in creating default behaviors that can be readily overridden.

• The use of linked structures and function pointers in implementing an object oriented language.
  

Finally, the student should also have improved skills in the domain of computational thinking as demonstrated by
an understanding and application of:

• basic computational linear algebra in three-dimensional Euclidean space

• intermediate level ray tracing principles

• design of an aesthetically appealing virtual scene consisting of a multiple sources of illumination and visible object
  

In the first half of the course,  students construct a simple ray tracer using object oriented design but written in the C language.  Advanced elements of the C language are used as follows to motivate object orientation as follows:

• Inheritance is motivated by the use of hierarchies of structures of increasing specialization that are linked via void *  pointers. For example,  the struct object_type resides at the top of the visible object hierarchy.  Below it lie the struct plane_type and struct sphere_type specializations.   The struct tiled_plane_type is a further specialization of the struct plane_type.
  

• Polymorphism is motivated by the use of function pointers contained in the structure at the top of the hierarchy which point to a default handler that can be overridden when specialized behavior is needed.  For example,  the get_diffuse_reflectivity()  normally returns the "color" of a visible object,  but must be overridden in the implementation of the tiled_plane object which has two "colors".
  

• A set of C language functions for managing generic lists of visible objects,  illuminating objects (lights),  and reflective properties is also developed and used to motivate the ideas underlying constructors and destructors.  
  

• C++ classes,  constructors,  destructors,  polymophism, inheritance,  operator overloading and the standard I/O library.

• Reimplementation of the basic ray tracer in C++.

• Adding textured surfaces, specialized illumination sources,  and additional quadric surfaces and surfaces of revolution to the model.
  

Course notes -

Lecture notes for the first half of the course,  covering advanced C programming, introductory linear algebra and basic ray tracing principles,  may be found here.   Notes for the second half of the course in which the C++ language and intermediate ray tracing are introduced are found  here.   

Closed lab materials and assignments -

The lab assignments are tightly coupled to the project and commonly used to illustrate standalone development and testing of system components.   The assignments used in the last offering of the course may be found here.

Other assignments -

The assignments used in the last offering of the course may be found here. In this collection, files whose names begin sp are short programs typically involving component development. Those beginning with mp are the two major project  deliverables. .

An important aspect of the Τέχνη approach is the use of open ended assignments. The final ray tracer consists of a collection of optional components. These components encompass a significant range of difficulty and are presented in class in order of increasing difficulty. The average student who seeks to earn a C in the course is presented a path to doing that is not unduly challenging. However, the top students competing to earn A's are challenged to the fullest.

Required elements - worth 60 points

• Ambient lighting with planes & spheres 
• Diffuse lighting / shadows             

Optional features - worth up to 110 total points @ 5 points each

• Finite plane                            
• Texture mapped plane      
• Spotlight                
• Projecting texture  
• Specular reflection
• Specular glints       
• Anti-aliasing
• Finite tiled plane of arbitrary orientation 
• Partial transparency
• A non-quadric surface of revolution

Assessment -

Assessment of student work -

Components of student work are weighted according to the following grading regime:

Final Exam                       15%
Mid-Term exam               15%      
Major Programs                25%
Short Programs                 15%      
Daily quizzes                     20%
Lab Grade                          10%

Daily quizzes -

A short objective quiz is given at the end of every class. This quiz covers material from the previous class. Student feedback has been very positive over many years regarding the beneficial nature of this practice. Quizzes may be found here.

Assessing the effectiveness of the Τέχνη approach -

In the spring semester of 2009, a common set of attitudinal surveys were given comparing attitudes of the students in  the Τέχνη class at Clemson University with students in an objects-early Java based CS-2 classes at Western Carolina University and at UNC-Wilmington.