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By KML Systems Ltd

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Amaze your friends by demonstrating your knowledge of the Hypotrochoid curve.

Artwork based on Hypotrochoid curves first became popular from the late 1960's onwards with the release of Spirograph®.

A Spirograph® set consists of a number of plastic gears and other shapes such as rings and straight bars. A pen placed through one of the holes in a gear piece will trace a curve as it moves against, and is constrained by, one of the other shapes.

One set of curves that can be produced using Spirograph® are known as Hypotrochoids.

TROCs is a program that will generate a hypotrochoid, or Spirograph®, curve.

These are curves created by tracing a point attached to a circle, at a specified distance from its center. The circle rolls around the inside of another circle which is fixed. Combining the radius of the 2 circles, and the position of the point, produces a curve which is often complex but aesthetically pleasing.

You can forget about the complexities of the Mathematics involved and concentrate on producing the curves and patterns by simply adjusting the values which control the appearance and shape of the final curve. Alternatively, use the random feature to generate a curve from one of more than 3 billion choices provided by this program.

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Customer Reviews

Fun toy! too fast to induce peace

What I liked: the enormous number of possibilities this app permits. I loved playing with each of the variables!

What I'd add/change:
I'd add a speed control in the "draw" function. I'd like to slow it down

I'd like to see the disks and frames with the gears moving in draw mode, or at least the option to see them. It's more like a real spirograph that way.

I like a lot of the features on a similar app, "finger spiro+" but what that app has in look and feel this app has in variables. I'd like to have the option to manipulate the gears myself, either via touch or gravity via the accelerometer. Maybe the gear could roll around the outer ring? Also, the old spirograph had non-circular inner gears too! You could add one or two of those.

Slow it down and it will help me relax more and induce peace. Softer color options, and the option to overlay multiple designs would also be cool.
One more thing. The real time changes of the image as on moves the variable sliders are cool, but i'd like the option to turn it off, enter all my parameters and then watch my creation as it slowly draws. Check out finger spiro+ and combine the good stuff about each! Overall I like it and I'll keep it, but I'm keeping the other one too. Thanks!


I'm way too high to do this

View In iTunes
  • $0.99
  • Category: Entertainment
  • Released:
  • Version: 1.0
  • Size: 0.1 MB
  • Language: English
  • Seller:

Compatibility: Requires iOS 2.0 or later. Compatible with iPhone, iPad, and iPod touch.

Customer Ratings

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