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# How to animate the Problem of Apollonius?

edited November 2016

Hi! I'm totally new to Processing, I hope to get your support!

Basically, I'd like to recreate this:

From Wikipedia: In Euclidean plane geometry, Apollonius's problem is to construct circles that are tangent to three given circles in a plane. Three given circles generically have eight different circles that are tangent to them.

My aim is to make the three main circles move inside the window with a random pattern, maintaining tangent the 8 others circles.

I found this code that represent a particular case , in which a circle degenerated into a line: https://gist.github.com/FreedomGrenade/4afcff17982c7299e683

Can you help me?

Tagged:

• What have you tried so far? Where exactly are you stuck? What exactly are you confused about?

• There are plenty of solvers online - this Java solution is easy to understand and can be easily adapted for Processing.

• Just asking if someone has did this before, I'm new to this program. I'm taking some class at the University, I only know basic functions.

I would like to know if exists a simple way to create tangent circles to three main circles, I don't know how to do it!

• I would like to know if exists a simple way to create tangent circles to three main circles, I don't know how to do it!

and there we hit the problem. What is simple to one person is not for another.

For me the answer is yes, there is a simple solution based on modifying the code in the link I provided. Obviously that is not the case for you.

The difficulty of this problem is in three parts.

1) Understanding the algebraic method used to find the 8 solution circles.

2) Converting the algebraic solution to some source code

3) Creating a Processing sketch to show the solutions.

Just asking if someone has did this before

I suspect that is has but who knows. Do you want a full code solution? If so I could run one up for you although you will learn more if you do it yourself.