To do these exercises you must run DX and the parametric surface program. When the image window appears, click on the Windows menu of the Image window and select the Open VIsual Program Editor (VPE) item. The program source should appear.

Remember that you can get help in DX on any module by selecting the "context sensitive help" item from the help menu, then clicking the left mouse button on a module.

• New Shapes
  Modify the control panel by typing in new expressions for x,y and z to produce:
  • A Ram's Horn
    w*.5*cos(2*pi*v)+w
(1+w*.5*sin(2*pi*v))*cos(2*pi*w)
(1+w*.5*sin(2*pi*v))*sin(2*pi*w)

  • A Helical Surface
    cos(2*pi*v)*w
sin(2*pi*v)*w
v

  • A Cylinder
    sin (2*pi*v)
cos (2*pi*v)
w

  • A Cone
    sin (2*pi*v)*w
cos (2*pi*v)*w
w

• Add a caption showing the x,y and z expressions.
  
  1. Add the following modules (refer to the program fragment for module placement):
     1. A Collect module from the Structuring catagory. Break the connection between the Normals and Image module and connect the new Collect module.
     2. A List module from the Structuring catagory. Add two inputs to it by typing cntl-A twice. Set the first input to {"X, Y, Z expressions"}
     3. Three Receiver modules from the Special catagory. Open each one and set their Notation fields to x y and z respectively.
     4. A Caption module from the Annotation catagory.
  2. Connect the modules as shown in the link above.
  3. Execute the program by selecting the Execute Once item from the Execute menu.

  The program will generate an image with a caption.

• Draw the polygon edges instead of a smooth surface.
  
  1. Add the following modules (refer to the program fragment for module placement):
     1. A ShowConnections module from the Realization catagory.
     2. A Tube module from the Annotation catagory.
  2. Connect the modules as shown in the link above.
  3. Execute the program by selecting the Execute Once item from the Execute menu.

  The program should generate an image with each connection shown (and with the control panel modified for a helical surface).