I thought LGPL licenses were bad. But Ogre is LGPL right? And it's being used in the Torchlight game. I wanted to use Cal3D for character animation. But I also want to be able to eventually go commercial too.

It depends on what you mean by "bad". If you don't want to allow your users to upgrade and re-link the LGPLed library with your program, then yes its "bad".

GPL is "bad" that you have to release the source code to everything the GPL code touches. Usually not a good thing with commerical software. LGPL is similar but if you link to the LGPL code as a dll and make the source to the LGPL available then its fine. With Ogre all of the code is in the various dlls and the source is freely available online so thats why they can get away with it.

Though with GPL you could release all the source code for free and then charge for the art assets. If your game is single player then them cheating is not really an issue.

Quote: Original post by 3DModelerMan
I thought LGPL licenses were bad. But Ogre is LGPL right? And it's being used in the Torchlight game. I wanted to use Cal3D for character animation. But I also want to be able to eventually go commercial too.

Both GPL and LGPL licensed software are used commercially quite alot, the GPL however requires you to release the sourcecode of anything that links with the GPL code under a compatible license (While this doesn't prevent you from selling the software the license allows any of your customers to make their own copies and sell at a lower price which tends to push the price towards $0 which basically means that you need a different business model to make it profitable (Selling the data is one option that can work fairly well since the Data isn't considered a derived work)). an MMO style game would also work just fine with GPL licensed code since you are primarily selling a service and you can still keep the server code secret since you're not distributing it to anyone.

However, even with a working business model you will probably end up giving alot of code away for free to potential competitors, If its worth it or not depends mostly on how much GPL licensed code you're using and how much work you spend modifying or adding to it.

This however means that in general you don't want to use GPL licensed libraries since a library is almost never a significant enough portion of your software for it to be worth the price of having to hand over all your code to the end user, The LGPL however makes no such requirements, it only requires you to allow the end user to replace / modify the library in question and you to provide the source to the version of the library you're using under the LGPL license)) (Normally this is done by linking dynamically, allthough it is possible to use static linking aswell without violating the license if you provide the tools needed to re-link the software) (The requirements of the LGPL can be a problem aswell in some cases if you don't want your end users to be allowed to modify any part of the software)

Ogre is "dual licensed". That is, for a fee you can buy a license that allows you to make modifications to the Ogre library without requiring that you release those changes (as you would be required to do if you used the LGPL license).

I can't say which version Runic used for Torchlight, but it wouldn't surprise me if they used the alternative license.

Quote: Original post by Codeka
Ogre is "dual licensed". That is, for a fee you can buy a license that allows you to make modifications to the Ogre library without requiring that you release those changes (as you would be required to do if you used the LGPL license).

I can't say which version Runic used for Torchlight, but it wouldn't surprise me if they used the alternative license.

Its quite likely that they did, most usage of LGPL licensed libraries i've seen in commercial games have been unmodified versions of smaller libraries such as SDL. (When you only have to give away code that is publicly available allready the cost of using LGPL libraries are fairly low)

Oh so you mean as long as I dynamically link the library it'll be fine? Then if I do manage to get a publisher and funding they won't turn me down for the fact that I'm using an LGPL library? I won't need to make modifications to the source code of Cal3D, so I won't have to release source code then right? As long as the DLL is included with the game? I mean it's only an animation system, if someone relinks it won't affect the gameplay too much, I was thinking of letting the game be moddable anyway.

Quote: Original post by 3DModelerMan
Oh so you mean as long as I dynamically link the library it'll be fine?

Generally, yes. There can be complications, see the GNU GPL faq for more detail.

Quote: Then if I do manage to get a publisher and funding they won't turn me down for the fact that I'm using an LGPL library?

A publisher does not need to tell you why they are turning you down. If the publisher has a rule against LGPL then that is their own business. A publisher may instead require that you have the proper business insurance and contractually provide indemnification.

Quote: I won't need to make modifications to the source code of Cal3D, so I won't have to release source code then right? As long as the DLL is included with the game? I mean it's only an animation system, if someone relinks it won't affect the gameplay too much, I was thinking of letting the game be moddable anyway.

That one is more complex, and you will need to talk with your publisher and your lawyers about it.

Quote: Original post by Codeka
Ogre is "dual licensed". That is, for a fee you can buy a license that allows you to make modifications to the Ogre library without requiring that you release those changes (as you would be required to do if you used the LGPL license).

I can't say which version Runic used for Torchlight, but it wouldn't surprise me if they used the alternative license.

Note that the upcoming version of Ogre (already available in SVN) is licensed under the far more liberal BSD license.

Quote: Original post by 3DModelerMan
Oh so you mean as long as I dynamically link the library it'll be fine? Then if I do manage to get a publisher and funding they won't turn me down for the fact that I'm using an LGPL library? I won't need to make modifications to the source code of Cal3D, so I won't have to release source code then right? As long as the DLL is included with the game? I mean it's only an animation system, if someone relinks it won't affect the gameplay too much, I was thinking of letting the game be moddable anyway.

You are actually required to provide the sourcecode to the version of the library you're using even if the exact same version is available elsewhere, If you intend to direct your users to the official website for the library you need to make sure they are ok with it and that they will keep a copy of the version you're using for as long as you are going to sell and support your software)

Its defenitely a better idea to bundle the Cal3D sourcecode with your application installer or place it on the CD/DVD. (Then everyone who is entitled to recieving that code will get it without any additional work from your side)