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Subject: 
Re: Modeling String
Newsgroups: 
lugnet.cad
Date: 
Wed, 10 Apr 2002 04:06:21 GMT
Viewed: 
439 times
  
In lugnet.cad, Larry Pieniazek writes:
In lugnet.cad, Jason S. Mantor writes:
I'm working on a program that simlulates strings as braided coils and lots
of splines in POV-RAY.  I'm tyring to get the catenary curves right so it
looks like it's tension is supporting it's weight....   Hopefully, I'll get
some time to finish it next week : )

Well I just slapped together a primitive to simulate twisted string bits but
am not all that pleased with it.

The string I have in mind to model will be so tight that a straight line
will be fine, no need for catenary curves (although it sure SOUNDS neat...,
or at least close enough for POVray purposes.

What are you using for primitives to model the individual sections of
string? I used a square section that was twisted 45 degrees from one end to
the other but that may not have been enough sides to get a good look. (my
first ever "primitive" Yaay!)

Perhaps we could also have parts, like the hose segments so you have a
"String End" and "String section" (for want of better names). These could
possibly be cylinders with a "wound" or "braided" pattern on them, the end
section having 1 closed end (maybe with a little fraying!). You can add them
end-to-end to get the length you want, with a nice pattern all along it.
Then maybe Fredrik (or someone else) could even change his ldraw-mode
http://www.math.uio.no/~fredrigl/technic/ldraw-mode/ to do catenaries as
well as beziers 8?)

You might also want a "String knot" part.

ROSCO



Message has 1 Reply:
  Re: Modeling String
 
(...) Incidentally, I have considered it. But so far I have concluded that the mathematics are too complicated for an analytical solution. And I am a bit tired of programming numerical optimalization.. Fredrik (22 years ago, 10-Apr-02, to lugnet.cad)

Message is in Reply To:
  Re: Modeling String
 
(...) Well I just slapped together a primitive to simulate twisted string bits but am not all that pleased with it. The string I have in mind to model will be so tight that a straight line will be fine, no need for catenary curves (although it sure (...) (22 years ago, 10-Apr-02, to lugnet.cad)

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