Box2D Forums

Just read an article claiming that you attended some sort of conference where the Rovio(Angry Birds creators) were doing Q&A. In which you stood and exclaimed that you created their physics engine.
That must've took guts.

You have awesome points in my book.

Original Article

How'd it feel? What'd the creators have to say? Will you be recognized for your hard work that brought them success?

This story really made me smile! Thanks for all of your hard work Erin. Box2D is truly a wonderful library, and I've always thought it was ridiculous that Rovio never even gave it so much as a mention. FWIW, Box2D gets a credit in my game, since without it my game would not have been possible.

Just to be clear, I did not declare that Angry Birds uses Box2D or demand that they give me credit.

The Q&A went something like this:
Erin: "Hi Peter, could you tell me which physics engine Angy Birds uses?"
Peter: "Box2D"
Erin: "Great. Would you consider giving credit to Box2D in your game?"
Peter: "Yes, of course"
Erin: "Thank you! By the way, I am Erin Catto the creator of Box2D"
Peter: "Great! I would like to talk to you after the session"

So I really tried to ask this in the nicest way possible and Peter was very friendly. Angry Birds is a great game and I have a lot of respect for Rovio.

Sometimes credit for Box2D slips through the cracks and I do not have any bad feelings towards Rovio. I am proud that my work could be part of such a successful game.

The question has come up about the Box2D license, which is zlib. The license requests credit, but it is not required. Thus Rovio did not do anything wrong. So why doesn't Box2D use the MIT license which requires credit? The reason is that some game companies are really touchy about using open source software for legal reasons. So I've been told that some companies will not use any open source software that is more restrictive than zlib. So I try to meet this requirement because I would like to make it easy to use Box2D.

So I want to encourage developers to give credit to Box2D, but at an absolute level it is not required. Yes, the world is not perfect.

Finally, the success of Box2D is not due to me alone. Box2D has a great community that has given me valuable feedback over the years to steadily improve Box2D. And of course, Box2D would be nothing without all the great games you folks have made with it. Thank you!

I really appreciate that credit is not required. In 2010 I did a number of contract projects for clients that would not put any credits in the games. My clients know i use box2d but when the game gets integrated into their site or virtual world there is no place for credits.

In my license work where i list my self in the credits, box2d (and wck) are always right on the list with me.

actually it might be fun to have an official box2d splash screen, or logo for posting on the credits screen.

Just out of curiosity, what does motivate you to work on Box2D Erin? If you walked away from this community, it would be hard for anyone to fill your shoes...

If you take money out of the picture, why would anyone create a video game? I'm guessing many game developers they would say they want to make a creative expression and that they enjoy bringing pleasure to other people's lives. For me it is not so different. I just happen to have an aptitude for writing physics engines.

I also want to say thanks for not having to put credit in the game, because otherwise I wouldn't be able to use it for work projects.

On the other hand, I feel that Box2D gets nowhere near enough credit, and so, when I release my own games that use Box2D (one of them very soon), I'll be making sure I explain that most things were made possible by Box2D.