One thing that's not so good about having the script code in the .htm side though is I guess you won't get script error dialogs displayed for any errors like you will in the .js file one, so that can make development a bit more tricky.

- Michael

Here is the hypotrochoid script, without sliders.
It is like the epitrochoid script, with a few changes to +'s and -'s.

Edit: Re-uploaded corrected copy of Hypotrochoid script. The old one appears to have been
the epi version. No one complained :-)

- Brian

There was a script query in the Geomagic forum about umbilic torus.
Uploaded the corrected script to the prior post.
Used the hypotrochoid script to form a deltoid. R = 9, r = 3, d = 3.
Drew a big circle and unwrapped it for a baseline.
Used twist and flow to make an umbilic torus. I'll guess that it is not distorted? May try a complete
script to check accuracy.

- Brian

The _Epitrochoid script does not properly place "corner" points on variations which have "cusp" points, such as the nephroid, etc.
Interpcurce just makes a sharp curve. Also some curves are drawn "twice"?

Hi Brian,

For fun I've created Epitrochoid.nod. See to work OK though I'm sure that it can be make much fancier by those more skilled than I am.

Oh, and I've also created Hypotrochoid.nod (or Spirograph.nod)

Mike.

Hi Mike,
You have made some nice nodes.


For radius settings 2, 1, 1, the nephroid, the "cusps" are not quite right, so maybe some refinement could be done. (?)

- Brian

Brian, I'm afraid that I don't understand in what way they are not right.

Below is a composite image of MoI output using radii 2, 1 and 1 and a grab from a Wikipedia page: https://en.wikipedia.org/wiki/Nephroid

Look pretty similar to me, or am I barking up the wrong tree?

Mike.

Hi Mike,

It is not very important. Just came up when I wanted an actual half nephroid.
I was just observing that zooming way in to a cusp point shows a hairpin turn, rather than a corner point, a result of interpcurve.
Identifying the cusp points, and ending the interpcurve there, would result in a "corner."

For example, for 3 cusps in an angle of 2 PI, the ratio of a/b = 3. Numcycles = 1/3 becomes 2PI/3 inside the js code, and yields one lobe.
Numcycles could be changed from an integerValue to numericValue.
Circular array, or 3 interpcurves would yield the full curve...


A ranunculoid has 5 cusps.

- Brian

No sure that I've fully understood the point that you are making, Brian.
Nonetheless it has made me see that the .nod needs to be able to input multiples of pi with much greater accuracy.
So the birth of Epitrochoid2.nod
Mike.

Hi Mike,

Have you seen AL2000 (Speedy) post:

http://moi3d.com/forum/index.php?webtag=MOI&msg=7777.355

He investigates similar curve forms using CV manipulation via vectors transformation.
In the absence of a mathematical formula, he follows a mechanical logic to achieve a similar result,
As a consequence it offers greater parametric control.
If you have not already seen it, I thought you might find instructive, as I did:

http://moi3d.com/forum/index.php?webtag=MOI&msg=7777.366

James

Thanks, James, it's very impressive.

CV manipulation?

Looks like I'll need to widen my maths knowledge to begin to understand the strategy of this .nod.
And it'll be weeks or months before I've nutted out the function of many of the nodes used.

Mike.

Hi Mike

Sorry, by CV (control vertices), I mean "points".

James

Thanks for Trochoid.nod - not quite so intimidating.

Hi Mike,

To help with analysis of nod file, I've relabelled several of the nodes,
& simplified the steps by using "progression" & "extract"
rather than "interp" & "splitPts".

The vectors tips can be seen as points on the minor circle
that rotates as it orbits the origin along the path of the major circle.

Let me know if this needs further clarification.

James

For the trochoid or trochoid2 nod, please explain why the line and cone "vectors" cannot be erased.

If saved and reloaded they can be erased.

- Brian

Hi Brian

to remove vectors set visibility of "rotateVec" to "No".
See attached

James

Thank you very much, James, I'll study this tomorrow.
Mike.

Hi James.
The visibility works, but once the bVectors have been applied, it is impossible to delete them from the MoI screen, even after nod is exited.
Is there some code running in the background?

- Brian

Hi Brian,

>>Is there some code running in the background?<<

I can't say; this is perhaps a question for Karsten.
He is the author of the vector nodes.

James

Thank you James.