Spirograph Project

I am trying to make a Spirograph drawing program using the formulas found here:


I am pretty sure I copied the formulas correctly, but all my program does is draw a circle. Anyone have any ideas? Thanks!
Here is the project.

May I see what you have so far in your project?

EDIT- Here is the project.

It works for me.

It also works for me, but sometimes it doesn't finish. Maybe you can improve that... :slight_smile:

The results you get depend critically on the ratios between those three slider values. Here's the best I've done so far, just putzing around:
Google%20Chrome001
(I'm too lazy to read the Wikipedia article to see what values they used for that animated gif.)

But anyway, a more Snap!ly way would be to use nested sprites:
Google%20Chrome002
All of the sprites are forever-TURNing, some clockwise and some counterclockwise. The one named "dot" has its rotation center at the black-dot end. The green dot at its outer end is the one whose pen is down.

The problem with doing it by drawing costumes, as I did, is that it's hard to get precise control of the (relative) sizes of the circles and the black rod. So one could argue for drawing a circle of a precise size and turning the picture into a costume.

I forgot to mention that I already solved the problem, it was just a plus were there should be a minus.

About your idea of making circles and nested sprites, If you look in the List section, there is a block labeled "old ideas" that is my attempt to draw costumes with a pen. Drawing them worked fine, and the rotation centers looked correct, but when I tried to animate it, the circles did not move correctly. My plan was to have one sprite move the circle and another on just draw them.

I have the red and blue circles turning ccw, but the black rod turning cw. But I think more important is that I clicked the little gray circle in the sprite corral icon for the blue circle.