Four Point Curves: This should be specified by a
sequence of control points entered using mouse clicks. On each left
click, the current click point should be recorded as control point i,
starting at 0. In a right click, erase the last point that was
input by the mouse. You code only needs to support a maximum of
30 control points. Be sure to print to stdout the x,y and i
values of a control point
when it is registered, the i value when a control point is
deleted, and warning messages when the user exceeds the bounds of i.
You will be implementing the Four
Point Scheme from the first two slides of Lecture 10.
***NEW*** There should be
least four control points before you perform subdivision, although
once there are four control points, your code should refine the user's
iteration 0 control points to the current subdivision depth
automatically and then draw the result. The last control point
should be connected by an edge to the first control point, forming a
closed loop so that all control points are subdivideable. Draw
the user's iteration 0 control points using glBegin(GL_POINTS) in one
color, and then, in a different color, draw the lines connecting
the fully refined control points using glBegin(GL_LINE_LOOP).***END NEW***
You will add key bindings to increase and decrease the level of
refinement (see Key Bindings Section). Print a message to stdout
displaying the new subdivision level when the user presses the related
button to change the value.
Here are the files of simple polyhedra that you will be working with. Here is a note on the format followed in these files. These polyhedra are very similar to the VRML objects from Project 1. You should write a simple routine to read in a file in this face-index format for use with your program. ***NEW*** Draw the fully refined surface either by iterating through the faces of the surface and using glBegin(GL_POLYGON) with different colors per vertex, or by iterating through the faces and using glBegin(GL_LINE_LOOP) to produce a wireframe. Use whichever method best demonstrates the subdivision process. ***END NEW***
You will add key bindings to increase and decrease the
level of subdivision refinement. Also, you will add two keys to
cycle through the five different polyhedra that you are given (see Key
Bindings Section). Print a message to stdout displaying the new
subdivision level or polyhedra name when the user presses the related
button to change the value.
Bindings: The following list contains all of the key bindings
that are required for this assignment. If you add any additional
keys, document your additions in the README file.
Here is some starter code that prints the pixel coordinates of where the mouse was clicked ***NEW*** and provides some basic memory management routines for the data in the Four Point Scheme. To build the project, type "make". ***END NEW***
Written Questions for Each Team Member (20% of the
1. Give one similarity and
one difference between recursive
and fractals in the way they generate objects.
2. What is the limit curve
when the Four Point Scheme is applied to a square? Assume that
vertices are spaced out equally on the perimeter of the square and that
there are at least 3 vertices on every side of the square (i.e. there
can be internal vertices within a side). What is the limit
surface when the Catmull-Clark Subdivision Scheme is applied to a
cube? What can you say happens to sharp corners in general when
these two subdivision schemes are applied?
3. Describe how you would
design a wide range of smooth 3-D models with holes if all you have are
a 2-D sketching system for line segments (like the one from this
project), a surface subdivider, and the ability to create surfaces of
rotation from 2-D models. Provide pseudocode.
What and How to Submit
Your program should compile and run on the Taylor or Painter basement machines. Then submit the following files:
The project3.txt file should also be a plain text file which should
answers to the above "Questions Related to the Project". Each group
member needs to create their own version of this file themselves and
then submit their own version electronically (see the turnin directions
You should grab the image of an interesting subdivision curve you generated and call it project3.jpg. You may do this by using xv command on Taylor/Painter basement machines. Save it as gif or jpeg file. Here is a note on how to grab a window using xv.
Each group should submit their code using:
--submit djeu cs354_project3_code [source code,
Makefile, README, project3.jpg, any additional files]
And each persons in the group should submit their written answers
--submit djeu cs354_project3_written project3.txt
Here is a note on how to use the turnin program.
OpenGl Reference book
Neider, Davis and Woo, "OpenGL Programming Guide" Second Edition, Addison-Wesley
Lecture 10 Notes on the CS354 Course