CS 285: SOLID MODELING, Spring 2002
Assignment #4
Parametric Modeling with SLIDE
This assignment further introduces you to some of the power of SLIDE
and of procedural modeling in general.
A) Parameterized Sweeps
The first part of this assignment you can do by just pushing sliders,
but it is a good idea to also look at the sorce file
to see what it takes to achieve the observed results.
-
Run the SLIDE program
SweepTube1.slf
and manipulate the various sliders to study their effect.
-
Create a twisted torus with an elliptical cross section;
choose the twist so that the tube closes on itself.
-
Increase the sweep angle to 720 degrees and adjust twist, radius, ellipticity, etc
so that a self-intersecting object results in which all surface intersections
occur at a steep angle (close to 90 degrees).
-
Now thicken the surface with the "surface offset" module,
and make it "semi-transparent" by expressing the surface as a grid
with solid square grid meshes
(Example: Moebius band).
Readjust the prameters so that all strut intersections are avoided.
With such a model one should be able to visualize more clearly how the surface penetrates itself,
and convey the notions that mathematicians have about such surfaces,
i.e., that you are not allowed to switch from one "sheet" to the other at such intersection lines.
-
Finally fine-tune all the parameters available to make a nice model
that could be manufactured on the Z-corp machine.
Change all the initial preset parameters on the various sliders
to those values that yield your prefered model,
so that when you next start up this program,
your design shows up without any further adjustments needed.
(For things that you cannot "freeze" in this manner, leave comments at the header of the file.)
-
Also capture your design visually using the screen saver
and make a JPG image of the display window.
-
Send me an e-mail with your parameter settings in the body
and with the JPG immage as an attachement before the deadline.
Sample Solution
B) Construct a Parameterized Bell
Your task is to design a curved (metal) surface of finite thickness
that has a good chance to sound good when struck and used as a bell.
There should be from 1 to 3 parameters that affect the shape of the bell.
Let yourself be inspired by this collection of
pictures and references,
but keep your shape simple!
You may compose your bell from primitives such as partial spheres and/or tori,
you can use spline patches, or you can use subdivision surfaces.
You may first design a thin (mathematical) surface in the desired shape
and then thicken it with the procedures demonstrated in part A of this assignment,
or else you may define its complete surface explicitly (allowing to vary its thichness).
Make sure you end up with a viable B-rep for fabrication.
Create a SLIDE file with all parameters set to their preferred values.
Also, capture your design pictorially using the screen saver.
Please-mail picture and SLIDE-file before the deadline.
These two tasks should be done individually by everyboy in the course.
I want to make sure that everybody gets comfortable with SLIDE,
and also has a chance to show their own bell-designs.
The Deadline is Tuesday, Feb. 12, 2002, 6am.
What you should also do
Study the
SLIDE documentation on the web.
After reading some of the background information,
familiarize yourself with the
SLIDE Language Specification, in particular with the
"Geometry" statements
and with the first five ""Geometry Node" statements,
"object" through "torus,"
as well as with the "polyline" and "sweep" commands.
You may also look at additional SLIDE example files in ../CODE .
PREVIOUS < - -
- - > CS 285 HOME < - -
- - > CURRENT LECTURE < - -
- - > NEXT
Page Editor:
Carlo H. Séquin
