Le 16-01-06 00:48, Mike Horvath a écrit :
> How do I create a spiral tube, like a spring? Like this:
>
> http://www.f-lohmueller.de/pov_tut/animate/anim16e.htm
>
> but a single object, not a union of spheres?
>
> Thanks!
>
>
> Mike

It can be done as an isosurface. In fact, there are two builtin 
functions that does just that.

In function.inc, those are: f_helix1() and f_helix2()

The various parameters controll the shape of the spiral, it's spacing 
and some other aspects. Those are some of the functions using the 
largest number of parameters.
The extent of the shapes generated are dependent on the contained_by 
object. Use a box just whide enough to contain the spiral and as long as 
needed.
Take some time to experiment.

If you want to use that shape in an animation similar to the linked one, 
you need to adjust the length of the box at the same time that you 
adjust the pitch of the helix.

If the amplitude of the sooilationsis relatively small, and the spring 
far/small enough, it may be possible to use some scalling, but the 
profile of the "whire" will also change.




Alain

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