POV-Ray : Newsgroups : povray.general : Re: Is there a math formula for making... : Re: Is there a math formula for making... Server Time
4 Aug 2024 22:14:32 EDT (-0400)
  Re: Is there a math formula for making...  
From: Tim Nikias
Date: 1 Feb 2003 19:32:07
Message: <3e3c6707@news.povray.org>
Well, the circumferance (no idea if that was written
correctly) of a circle is 2*pi*Radius.
So, divide that by the diameter of any given cylinder,
and place these along the circle.
This is a very crude method, and you'll probably end
up having the cylinders overlap slightly, or somewhat
apart, making them somewhat larger/smaller (by a given
percentage probably dependant on amount of cylinders
in total, that's trial and error, I guess).

So, lets see:
You've got a cylinder with diameter 3 (radius 1.5 = diameter 3),
and you want it 80% smaller, that's 2.4 diameter for the
new cylinders.
So, 1.5 radius of initial cylinder + 1.2 radius of next cylinder,
that equals a circle with radius of 2.7.
2*pi*2.7 = 16.96.
16.96 divided by 2.4 (diameter of new cylinders) = 7.069,
roughly 7.
You'll have 7 cylinders to be placed in the next circle, so divide
360 degrees by 7 and place them with that much apart in angle
(using something like rotate y*360/7*Cylinder_Number or so),
and perhaps need to increase the radius of them a bit to have them
touch.
Apply the same thing for the next circle:
Initial radius of 1.2 times 80%, add that to the radius of 2.7
we have right now, multiply that with 2*pi, and divide by
Init_Radius*80% (this is rough code ;-) and place em. Repeat...

Hope it's clear what I'm trying to say. If not, just ask again, if
need arises, I might even write the script for ya.

Regards,
Tim


--
Tim Nikias
Homepage: http://www.digitaltwilight.de/no_lights/index.html
Email: Tim### [at] gmxde

> I couldn't explain the request within the subject line so I'll try to
> explain it here.  I am trying to create several sets of cylinders. The first
> cylinder is located dead center <0,0,0> and has a radius of 1.5.  I want to
> place smaller (maybe 80% or so smaller) cylinders around the outside edge so
> that the cylinders all touch each other and touch the middle cylinder.
> (perhaps nine or so.) Then I want to make another set outside the last of
> cylinders (a little smaller still) that all touch each other and the
> cylinders below them.  I want to get smaller and smaller cylinders until
> they are very small (perhaps 0.1 or so) at a distance of +6 from center.  I
> am including a small (very poor) drawing of what I'm trying to accomplish
> (although I want the cylinders to go all the way around.)
>
> Is there some math formula that would correctly create these?
>
> Patrick (math impaired) Dugan
>
>
>
>


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