Algodoo

They are so light that they are essentially helium balloons. That's cheating!!

If you can implement true PID control as you did in your Matt Balancing Spoon scene, then you will have a truly impressive scene!

Helium has a density of 0.005 kg/m2 in Algodoo. These devices have a minimum density of approximately 2.0 kg/m2. Your first statement that "They are so light that they are essentially helium balloons" is false.

What do you think about the code in the "update" event of the circles?

Sounds like you would be impressed with greater complexity, but a simpler solution may be more elegant. You will have to dig deeper to find out how this really works.

I will give you a hint. There is a "red herring" in this scene. Seems like you may have already found it.

[quote}Your first statement that "They are so light that they are essentially helium balloons" is false. [/quote]

OOPS! I was reading the value incorrectly. When I saw the value "2-80 kg/m2", which is the combined densities of both the circle and the box, for some dumb reason I was thinking it was a single density of "2^-80 kg/m2"! DUH!

[quote]What do you think about the code in the "update" event of the circles?
[/quote]

Very clever using the density value to correct the balance. It may not be the tight control that PID provides, but it does seem to work!

[quote] Sounds like you would be impressed with greater complexity, but a simpler solution may be more elegant. You will have to dig deeper to find out how this really works. [/quote]

Well, complexity does have its place, but I prefer the "Occam's Razor" philosophy of simple is better. I believe I did figure out how it works, and yes, it did require some digging. Again, very clever!

Regarding "Very clever using the density value to correct the balance. It may not be the tight control that PID provides, but it does seem to work!":

That code is bogus and doesn't do anything to help the balance. That code is the "red herring" that I mentioned before.

I don't believe you figured it out yet. Let me know if you give up and I will tell you the answer. Here is a hint: ABCDEFGHIKLMNOPQRSTUVWXYZ.

Got it! Attached circles hidden in collision layer J act as counter-balances. No control script needed. Did I get it this time?

Yes. That is the first time I put fake code in a scene. I thought it would be amusing to see if anybody would catch it. I figured that most users would not look for the code, and those that found the code would assume it worked. I figured (correctly) that you would be the only one (out of thousands of users) who would be inquisitive enough and dig deep enough to find out how it really works.

You fooled me because I had no reason to believe that you would put fake code in a scene. You are a talented engineer who has produced some clever designs and clever coding, and it looked like your fake code could actually work. That's why your fake code was so deceptive! Nice work. (I'll see if I can fool YOU some time in the future when you least expect it! )