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Topics: User Forum
Sep 1, 2009 at 1:06 PM

Hi, I've just released a Farseer project I've worked on for a while, called FreeGoo

It's a simple free clone of the game World Of Goo. Let me know what you think

with regards,


Sep 1, 2009 at 1:29 PM

World Of Goo is one of my favorite games. Nice to see a Farseer Physics Engine based clone out there. Keep up the good work.

Sep 1, 2009 at 2:19 PM

Yeah, World Of Goo is the funnest game I've played in years.

There are a couple of things that I'd like to see in freegoo that would make FreeGoo better - specifically, the collission code is too slow. I had to turn off inter-particle collission for sleeping particles, because if I turn it on the entire game slows right down. There is an old forum entry where someone outlines how you could make a sphere-sphere collission detection optimization, which would be great, but the forum code didn't work for me.

Anyway, thanks for a great physics engine!

with regards,


Sep 1, 2009 at 2:41 PM

Yer faster sphere vs sphere collsions are something that I have been wanting for a while too. It is in the works however for farseer 3.0 or 3.1 so we will have it soon.

However if you ever do figure out how to do circle on circle collsions please let me know. If i ever find out how I will let you know too.

Nice looking game by the way. The way the physics feels holds up well to the original.

Sep 1, 2009 at 3:31 PM

Thanks, I take it you got it running ok?

If I figure out how to make sphere/sphere collission, I'll let you know, but if it's coming with 3.0 or 3.1, I'll wait for that.


Sep 1, 2009 at 3:34 PM

Yer i got it running fine. Quite cool.

Yer farseer 3.0 or 3.1 i think will have it but you would have to ask genbox if it is planed for the first version of 3.0 or not.
Also it may be quite a while before we get farseer 3.0 i dont think there is a timeline yet so much as we are waiting for box 2d to finish some things first... but i would think around a month from now.


Sep 1, 2009 at 7:22 PM

That is correct. 3.0 will have real circles and it will be a lot faster than FPE <=2.x.

I can imagine that you have a lot of joints activated. I've never looked too much into the joints and thus there could be a couple of optimizations. Also, make sure to test the performance in release mode. Your game should be 2x faster in release mode.

To see different optimization techniques, take a look at my blog. Simply click the "optimization" tag to the right to see optimization related posts.

Sep 1, 2009 at 7:40 PM

Then I'm officially looking forward to 3.0 ;)

I'll also read up on optimizations, actually, the joints arent't the big killer in my case, I can manage quite a few joints, but once particles start interacting, I'm dead in the water.

Keep up the good work with the engine, it was really clean and nice to work with - I've previously worked extensively with ODE (I wrote the original dll importer to delphi for ODE) and Farseer is much cleaner. Though ODE has a C wrapper for C++ classes, so it's  bound to be messy.


Sep 1, 2009 at 7:46 PM

Simplicity is one of our main goals. We hope to keep 3.0 just as simple and clean and provide a fast and stable simulation.

I hope to see FreeGoo evolve (as Goo's does ;) ). Don't hesitate to ask about anything Farseer Physics Engine related.

Sep 1, 2009 at 7:52 PM

Oddly enough, I've never found that I had to ask about anything yet. And I don't consider that as a testament to my knowledge of physics engines, but instead of the usability of Farseer! Oh, I did create a joint of my own. It didn't work that well. After a while, I figured out that one of your original joints did _exactly_ the same thing, only better. Guess it teaches me to read the manual, eh?

So.. you're from Denmark? Nice country, though your languange is decidedly strange...

cheers from sweden,


Sep 1, 2009 at 8:00 PM

hehe, took me a long time to write that manual. Even tho it seems you know how to do stuff yourself, the manual is a great reference book.

Yes, I'm from Denmark. It's pretty nice country - and you are right; the language is very strange indeed. I like British a lot more. (even tho I write American here)

Sep 2, 2009 at 2:20 AM
Edited Sep 2, 2009 at 2:21 AM

Wow! i'm very impressed, it seems like a great start to a free version of one of the greatest puzzle (i think it's puzzle...) games around!