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Havok Releases Free Version For PC Developers
An anonymous reader writes "Havok has released the free version of its widely-used physics and animation engine (but without source code), including tools that integrate with Autodesk 3ds Max and Maya. Developers may use Havok for free for non-commercial games, middleware, and academic projects. Here are the SDK and tools."
As others have pointed out, its going to be hard to integrate this with other FOSS libraries. Even though Ogre is LPGL and not GPL, I don't think its possible. But we do have ODE (Open Dynamics Engine) to work with. It'd be interesting to see how Havok compares to ODE.
True, I think you could integrate this with BSD code. How many game libraries are available in BSD though? I think most of them tend to be GPL or LGPL. Ogre is LGPL as is Crystal Space. OpenTNL (game networking) has both LGPL and commercial licenses.
Of course, you could probably integrate this with a slew of commercial engines.
I'd say GPL restricts certain freedoms for the sake of others that are, in the opinion of the FSF, more important. Not a big deal from my perspective.
Why would OSS want Havok? We already have Bullet, it's actually Free Software, and widely integrated. This release of Havok is due to the Free Software physics libraries gaining traction in the commercial game development world and eating into Havok's market.
The thing is, the Havok free license requires you to distribute your whole software package as binary only. That's incredibly un-friendly to Open Source. Sure, there could potentially be an open source license which doesn't require shared libraries you link to be open source as well (actually, in reading the GPL, I think you could make the case that you could even distribute your software under the GPL if it links to proprietary libraries, because in as much as those libraries are not really part of your program, they wouldn't have to be covered by the GPL), but even if you used such a license for your software, you STILL couldn't link your software with Havok, because the Havok license *requires* you to NOT distribute source code to people. The Havok license is FAR, FAR more restrictive and obnoxious than the GPL ever was or will be.
How is it possible to write GPL code for windows, then? All windows software links to proprietary win32 libraries.
What I want to know is: how does it compare to the existing Open Source physics libraries, such as Bullet (which was made by an ex-Havok developer)?
Warning: It's been a few months since I've touched physics engines... so maybe things have changed somewhat since then.
ODE's solver is horrendously slow compared to commercial physics packages. The plus side is that it has a more physically accurate solver... which unfortunately most games simply do not need. ODE is geared towards physical SIMULATIONS, whereas Novodex/PhysX and Havok are built more towards *looking* physically correct, as opposed to being *actually* correct. The difference is in the scale of physics problem they can solve. Havok has proven itself able to crack thousands of interacting rigid body objects, while ODE buckles on the same hardware.
As for Bullet, I really don't know... It's a very young project and I haven't had much experience with it.
They don't want anyone to profit from the free version.
It would be entirely possible for someone to use a hypothetical GPL version to make a commercial game; they would have to distribute the full source code to the game engine, of course, but the artwork, soundtrack, gameplay, etc could all remain non-free, so the game as a whole would be commercially viable.
Of course, it's true that only a tiny minority of commercial developers would be interested in that kind of business model, so maybe the open-source game development community should get together and petition Havok to go the extra mile. Maybe they don't understand the protections the GPL would give them, or just hadn't thought of it. It can't hurt to ask, right?