Hi all.
The background of my story is that many years ago I was about to write a game based on the same idea as "Bad Piggies". I was coding in my spare time, thus development was slow and finally guys from Rovio overtook me. I'm not sure about the future of my game now, but if it is going to be abdandoned, then maybe it is a good idea to share some of my work.
Core component I was focused on was a physics engine. At the time I started to develop I was not happy with physics engines I had tested and I decided to write my own one. To my surprise literature was somewhat evasive (or maybe I searched not good enough) on aspects of dynamics I was interested in. For example I was not able to find how to deal with collisions of multuple bodies at multiple collision points or how to assure conservation of energy in the system after collision. I decided to derive formulas on my own. It was fun and I ended up with a bit of theory on which my engine could stand. A piece about collision handling was put into LaTeX and the resulting pdf is what I would like to share in this post. The rest depends on your feedback; I hope that your reaction will help me make further decisions.
Note: Project is hosted on sourceforge, but the code there is pretty old. Major update is waiting on my local drive, but I would like to hear opinions before moving on. I don't know if project makes any sense to anyone.
[attachment=14778:GPX_collisionHandling.pdf]
Paper was reviewed by my dog, so sorry for any kind of typos, bugs or bad grammar ;)