A parametric 2D logarithmic spiral should be easy to do.
A less aesthetic, parametric 3D logarithmic spiral with sines, cosines, and exponentials is easy to do.

Escargot with 3D logarithmic spirals of constant curvature and torsion, turned out to be a lot more mathematically involved, and harder to program, than I thought.
Yoshida, and also Gur Harary describe how to do it.

Does MoI currently have any Log-Aesthetic Curves, such as described by Yoshida, and Levien?
Is there any Dormand-Prince or other Runge-Kutta algorithm accessible in MoI?
I have found a few on the web.

Also, it seems like the Euler Spiral would make a good building block?

EDIT: Ignore. Works good now, without my dumb bugs.

Well, my Logarithmic2D spiral crashes MoI, both version 2 and 3Beta.

Seems to be a problem with the Math.exp() function?
In MoI2 the curve/line is going to infinity it seems.

Hi Brian,

> Does MoI currently have any Log-Aesthetic Curves, such as
> described by Yoshida, and Levien?

I'm not aware of any...

- Michael

> Well, my Logarithmic2D spiral crashes MoI, both version
> 2 and 3Beta.
>
> Seems to be a problem with the Math.exp() function?
> In MoI2 the curve/line is going to infinity it seems.

Is it following the same general pattern as the other function curve scripts?

But definitely trying to go off to infinity or very large numbers will be problematic - if you have an infinite curve you need to narrow the points you generate on it to some more localized sub range.

If you'd like to post the script I can take a look at it - sounds like it may need some debugging.

For debugging purposes you can put in calls to moi.ui.alert( 'message' ); to pop up a message box showing a string, or you can also call moi.log( 'message' ); which will write a message to the debug log. To see the debug log output hold down the Ctrl key and click on the "MoI" title text in the upper-right corner of the window when it is maximized (near the window minimize/maximize/close buttons), and choose "Show log" on the debug menu that pops up.

- Michael

Thank you Michael.
I'll try some debugging.
Crashing only occured when trying to see more of the infinite curve...

After correcting a few simple bugs, (failing to name variables properly),
now have a parametric 2D Logarithmic Spiral.
Ran a simple Sweep with two circles.
The script is of the same pattern as other simple parametric scripts, based upon the ToroidalHelix Script.
Just plug in the proper simple parametric equations.

To use the script, just unzip it and copy the two files to the MoI3Beta command subdirectory. (Same subdirectory as MoI2. (Currently))
Then set up shortcut key under MoI3 options icon. (Can also do shortcut key under MoI2 options icon, for MoI2 usage.)


It might be nice to distribute the points more uniformly, not cluster them in the middle.

Bemfarmer,

When are you going to cut some of these cool models/scripts? I hope you haven't been neglecting your Hybrid... :)

Bob K

Deleted.
Anyway, MoI is the greatest program.

Thanks bemfarmer, for another useful script!!!

Made a 2 turn red logarithmic spiral, then did tab Rebuild.
Rebuild really cleaned up and reduced the point count.

Then did an overlaying 3 turn blue logarithmic spiral.

The two spirals are very nearly the same.
Zooming in shows a slight difference in the two curves.

Made some 2D marbles.

Hypnotic!

A quick "yin & yang", 2D log spiral, using the superb, and incredibly easy to use MoI program!
:-)

WONDERFUL! Great use of Moi 2d toolset.

The Lollipop Guild would be proud! :-)

Awesome creation!