Author Archive

Double Engine – contacts and friction

Thursday, October 7th, 2010

I’ve been working on the physics module of the Double Engine for the past week and after lots of trouble, it finally works the way I wanted.
I started by following the contact forces tutorial on My Physics Lab, but the method wasn’t working for me, even the simplified Gauss-Seidel I found here.
Fortunately, I was lucky enough to get help from Scott Lembcke, the author of the Chipmunk Physics Library, who was kind enough to answer all my questions on the TIGsource forums. His answers, together with his paper and the source of Chipmunk, helped me get rid of all my problems and to generally fix my code. Big thanks to you Scott :)

In the video below, you can see how friction (thanks to it the ball can roll around instead of just sliding) and contacts (the objects can now stack without interpenetrating each other) work.

It feels so good to have this working properly. Now that this is finally done, we can begin development of our second game, more info soon!

Trajectory 1.1 update

Monday, August 16th, 2010

A few days have passed and I noticed the game really lacks some sort of a single player gameplay, so I added a simple AI with three difficulty settings. Download and enjoy.

Trajectory for Windows

Trajectory for Linux

Now that was short and straight to the point ;)

Trajectory 1.0 finally released

Friday, August 13th, 2010

Whew, finally it is finished. There may be problems with running it in fullscreen (on Windows) but when in windowed mode it should be all right. The controls and resolution could be easily changed through the menu, you have to restart the game for resolution changes to take effect. In case you mess something up and the game won’t start, try removing the ‘conf’ file.
Specifics on how to play the game are also in the game menu.

Trajectory for Windows

Trajectory for Linux

Just download the package, unpack it and run ‘trajectory’.
Leave comments if you have anything to say about the game :)

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