The procedures referred to in these problem express patterns that vary according to conditions. The problems have you modify an existing procedure from chapter 4. Problem 5 requires that you completely develop a procedure from scratch.

The first four problems are based on the procedure to draw red and white tiles from Chapter 4.

You will modify the procedure to draw the following patters. The modification of problem 1 is trivial:

Problem 1. Modify the procedure to draw tiles in chapter five such that the following pattern (trivial). Save your procedure under project file tilev1.gct.

Problem 2. Simplify the procedure to draw tiles of problem 1 so as to draw the following pattern Save your procedure under project file tilev2.gct.

Problem 3. Modify the procedure to draw tiles in problem 2 so as to draw following pattern. Save your procedure under project file tilev3.gct.

Extra Credit Problem 4. Assume that the procedure of problem 3 produces a panel within a larger pattern of panels. Redevelop the procedure such a patterns of some number of rows and columns of panels is produced.Save your procedure under project file tilev4.gct.

Problem 5. Develop a procedure on your own to draw any decorative, tile or other architectural pattern that varies according to conditional and/or logical operators. The pattern can be a tile pattern or border patter or some combination of the two. The Greek Fret patten below was generated by such a procedure. It is more challenging than the tile patterns above due to the assymetry of the geometry in a few cases. For example, compare the middle shape of the top line with the middle shape of the bottom line in the figure below. They are oriented in the same direction, not a mirror of each other around the center-line of the whole pattern. This is typical of a number of frets within the pattern, and thus more challenging than a repetition of single pattern.

Greek Fret Border Pattern (Procedure written after Jones, 1865)

What you need hand in:

1. Save your GC script files  into your "submit" sub-directory under a folder "exer4".

2. Send email to Earl Mark ejmark@Virginia.edu and to both David Malda dcm9b@virginia.edu and Michael Plehn mep4d@virginia.edu that describes the work you have done. Submit a few paragraphs documenting your research and any observations you may have made.

Feel free to visit or email me should you be in need of assistance.

What is to come:
In the coming weeks we shall consider how geometry may be developed in 3D as a consideration of more extensive embedding of procedures within procedures. We will extend this to consider how such a sub procedure approach reflects an effective abstracttion of the top level procedure.