Porting Xonotic to idTech 4

When switching engines, compatibility with current assets is clearly needed, as otherwise this is not "porting", but
"starting from scratch". As far as I can tell, this rules out anything not derived from the Quake family of engines.

I had no issues porting assets from DP/id Tech 4 to UE4. Regardless what engine you switch to, you'd have to rewrite materials/shaders/particles. As for models/textures - it's almost straight re-export. If using UE4, BSP can be directly imported, so maps can be brought in directly and only lighting/entities would have to be tweaked.

If I were to be asked, for Xonotic, I'd strongly advise against using an engine with anything but a free (GPL, MIT, BSD etc.) license. Back when I was still actively involved, a lot of contributors cared deeply about the "free-as-in-freedom"-part of this project - and I don't have the impression this changed much.

That's where the problem lies. If you think it's a blessing, you are plain wrong. It's a curse in modern days.

Back in time, where there were no freely available high end engines / tools, that was a blessing indeed. It was easier to find ideologically driven people to fill in teams in free projects.

Not so much nowadays. It's easier to find a contributing artist/programmer/scripter for UE4/Unity based games than for obscure ancient tech.

Also note that I think that I'd seriously miss NetRadiant.

Don't miss it. Use it. UE4 has a plugin that allows direct import of Quake1/2/3/Doom 3/HL2 BSPs. So you map with existing CSG tools (Net/GTK/DarkRadiant/Hammer) and bring it to UE4.

Throwing away more than a decade of code and assets for the benefit of switching to a more modern (but non-libre) engine looks much too risky for Xonotic IMO, though.)

That's true. That's why it makes more sense to finish Xonotic 1.0 with DP and then start with Xonotic 2.0 using UE4 (or Source).

I would definitely be happy if someone took Storm Engine 2 and finished the job I started (especially fixing multiplayer). However, that's not going to happen, ever.

It's really nice that UE4 can import a lot of stuff. However, I'd *guess* that the import is "one-way" only, meaning that while you can import BSP files, there's no way back into NetRadiant, meaning that after this point you are bound to the Unreal tools if you don't want to repeat the tweaking-after-import every single time you change something in NetRadiant. It's certainly a useful bridge to have, but I guess it's one-way.

Also the licensing terms are really problematic: https://www.unrealengine.com/previous-ve...-resources

Can I release a UDK game as open source?

The rights to develop and release a game for free are contained in the end-user license agreement (EULA). The EULA is also the license that governs the release of your game as it's built on UDK. You can't release your UDK project under terms other than the UDK EULA (like GPL, LGPL, open source, etc.). You don't have the right to encumber the UDK with terms that we have not already granted to you.

Or something from the EULA:

5. Ownership. As between the parties, Epic or its suppliers (as described in Section 1) own the title, copyright, and other intellectual property rights in the UDK, including all derivative works of the UDK.

So basically, the EULA is viral as the GPL, but without the copyleft. For me, this is killing it right there. I'd feel no incentive whatsoever to contribute to a codebase licensed as this (unless this was the way I'd earn my money, which it thankfully isn't).


Again, for free-as-in-beer or commercial projects UDK looks like a really good option, but I just don't see it fitting Xonotic, which in parts is defined by its open-source libre nature.

I don't see how GPL is relevant to a good free game. GPL is a religion, in this case. It's not a benefit for the project, at all. Free is free. People download it, play it, enjoy it, come back and/or contribute. GPL is irrelevant when it comes to the product.

So no, licensing only becomes problematic when you put GPL license and Stallmanship above product and its users. Otherwise EULA and non-GPL terms don't matter. You can distribute your free game made with UE4 anywhere. People don't care what you coded and if it's under GPL. They just want to play the game, for free, and perhaps share it with friends. There is nowhere UE4's license/EULA prevents that.

Btw, UDK is obsolete. I am not sure why you quote its EULA here.

UE4's EULA is here: https://www.unrealengine.com/eula

You own all content you make and IP is yours, except for the engine. And if you never made your code available to Epic, they don't own it (it doesn't count as "Contribution").

So yeah, if you guys are bound by ideology, better stay with DP (or spend years switching to another GPL engine). MIght as well make a FAQ where you clearly outline this, so everyone is aware.

It's not expressly stated on the FAQ, probably because it's not a very frequently asked question The last questions on the FAQ page do a nice job of illustrating why keeping Xonotic free (and independant!) was and is very important to its founders and pretty much everyone who has been involved with it since.
Besides, most people who know about the GPL will consider a project like Xonotic, where not only the engine but also ALL assets are covered by the GPL, a project driven by a certain amount of conviction.

Personally I would rather not have a Xonotic than have a Xonotic that is not free. The developers past and present that I know largely feel the same way. This is one of those hobbies that only costs money. Except maybe, for the only person so far who agrees with you

Which also means that this product does not have to be made. Yours does, as you are an indie developer and you want to try and make some money. Your product would probably not even exist without you as the driving force behind it. So I absolutely understand your choices for your own projects, they seem logical to me. Furthermore I applaud your efforts to make good games in the current gaming market. Make some awesome things and have fun with it, please!

What I do not applaud is the seemingly condescending attitude towards the choices that the team behind Xonotic has made. "Praying to Richard Stalman" and terms like "religious" make it look like you think we have all lost our collective minds. I can assure you that quite the opposite is true.

My support for the GPL is certainly not about religion or being particularly fond of Richard Stallmann. For me, in the context of games, this is mostly a question of reducing dependencies, increasing the chance of longevity and empowering the community. For instance, I have reasons to believe that I can play Doom (1993), Quake, Quake II and Quake III for as long as I live. For Unreal Tournament 99 and 2004 the situation is much less clear, and the Linux ports already suffer from such severe bitrot that it's an adventure to get those running on modern systems, so I avoid proprietary stuff where possible.

I love GPL for the exact same reason why some hate it: It guarantees that anything open-source stays open-source forever! I'm a bigger fan of LGPL personally as it's a bit less restrictive, but this is definitely the side of things I enjoy most.

If you want to experience the true wonders of relying on proprietary software, Windows 10 is a great example you can start with! Upgrade now, and experience the full benefits of: Microsoft logging your pressed keys, Microsoft listening to you in your own home via your microphone (courtesy of Cortana), updates you can't verify forcefully being installed on your machine, your computer restarting by itself while you're working on something, Microsoft having the ability to remotely shut down your machine if it so pleases, and much more. What's that? You were using Windows 7 or 8 back when we considered Windows sane and safe? Too bad! You will be forcefully sent to a Windows 10 installer in a few months, because the owners of your OS said so.

So yeah: Build your game on an engine owner by a mega-corporation, and be surprised once you find out that your game ultimately belongs to them, and they'll do what they want with it through its engine

My support for the GPL is certainly not about religion or being particularly fond of Richard Stallmann. For me, in the context of games, this is mostly a question of reducing dependencies, increasing the chance of longevity and empowering the community. For instance, I have reasons to believe that I can play Doom (1993), Quake, Quake II and Quake III for as long as I live. For Unreal Tournament 99 and 2004 the situation is much less clear, and the Linux ports already suffer from such severe bitrot that it's an adventure to get those running on modern systems, so I avoid proprietary stuff where possible.

That's understandable. If I had a programmer to help me finish Storm Engine 2, I would have probably not switched to UE4.

If DP got direct light source and cascaded shadow maps, and a few minor enhancements (not even rendering eye candy), I would probably still used it too.

However, there lies the core issue - all these open source engine (mostly ID tech) run original games just fine. When it comes to projects built from scratch or mods doing something outside of the scope of original games, those projects/mods need a programmer who sees it through and willing to support it. The problem is that there are only a few such programmers. They only work on their own projects and not willing to contribute to any other projects that use the same engine (or they are limited to one of the aspects of the engine). That doesn't help engine to evolve beyond certain point and at the end of the day, the longevity of said engine is limited.

So whether it's FOSS engine or commercial engine, they are both going to limit developers at certain point (lack of support and advancements with FOSS engine, and license change or whatever for commercial engines).

The point is (unrelated to GPL really) that UE4 has the tools and talent pool that allows you to get your game (free or not) to where it should be in a much shorter period of time. Whether other engines (which happened to be GPL, but easily could have been closed sourced) don't have such tools and talent pool.

Anyhow, it veers off to GPL vs non-GPL subject, which isn't the topic

Note that I don't hate GPL per se. I made Steel Storm using DP and GPL tools, working on Linux. That experience opened my eyes, and that's why I generally advocate against GPL engines when there is a good alternative in the form of UE4/Source/Unity/CryEngine.

I don't know how serious people are about this, but I would be very interested in helping port the game over to UE4. If this becomes a major thing, I'm definitely onboard.

I don't know how serious people are about this, but I would be very interested in helping port the game over to UE4. If this becomes a major thing, I'm definitely onboard.

If you read page 3 and 4 of this thread you'll see it's not going to happen.

The only way to make it happen is to start Xonotic 2 from scratch using UE4.

We could use UE4, it supports Linux, Mac, Windows, Steam OS. But UE4 isn't Open Source...

We could use UE4, it supports Linux, Mac, Windows, Steam OS. But UE4 isn't Open Source...

That's why I suggested to start a new game from scratch, by the devs who don't really care about FOSS ideology.

OK so we all agree then: some hypothetical devs might make a game that is not Xonotic, with diffferent assets and in a different non-FOSS engine.

Maybe Illfonic could help?

OK so we all agree then: some hypothetical devs might make a game that is not Xonotic, with diffferent assets and in a different engine.

Well, can't they still call it Xonotic 2 ? For sure they can make it competitive FPS game with similar mechanics. Just not sure about the name.

Please no! Not this nightmare again! Stop it!

As mentioned earlier there is some ongoing development regarding a Daemon-Engine port: https://gitlab.com/xonotic/daemon In my humble opinion this is the most sane way to update Xonotic's engine. It stays FOSS and keeps compatibility to all previously used tools while upgrading the code base and opening new possibilities for better graphics.

OK so we all agree then: some hypothetical devs might make a game that is not Xonotic, with diffferent assets and in a different engine.

Well, can't they still call it Xonotic 2 ? For sure they can make it competitive FPS game with similar mechanics. Just not sure about the name.

Why bother with a "2". Might as well just call it "Xonotic" and let it use our existing xonotic.org domain name. We can just change the free software Xonotic's name to something else.

Just kidding! That stuff would never happen.

/s

I can't believe you're trying to imply that turning Xonotic into a proprietary game would be a good idea. I hope you realize the irony of that suggestion.

I can't believe you're trying to imply that turning Xonotic into a proprietary game would be a good idea.

Just because it's not under GPL doesn't mean it's proprietary.

Either way, just sayn'

So anyway, I realized I did not know a lot about UE4 at all so I did a bit of reading.

What it seems to boil down to is that Epic Games are releasing a game engine and dressing it up as a kindness to the world, when in fact it's just another way to make money for them. They want people to make games so that if they are in luck and it does well commercially, they can reap the benefits in the form of royalties. Is that a somewhat accurate description?

Yes, i think its pretty much like what Valve does - instead of making their own games and selling them they just sell others people's games.

I can't believe you're trying to imply that turning Xonotic into a proprietary game would be a good idea.

Just because it's not under GPL doesn't mean it's proprietary.

Either way, just sayn'

I said nothing about GPL, so I'm not sure what you're talking about there. The UE4 engine is proprietary, and you can't say that a game is free software if it depends on a proprietary engine.

I appreciate that you're trying to share your experience as a game developer, but you haven't explained why you think it applies to Xonotic as a free software project. If the only things that matter to you are profit, adoption and convenience for contributors, your advice makes sense, but you're neglecting that the free software aspect of the project takes priority over that. It's unfortunate that FLOSS game engines and tools aren't as powerful as their proprietary alternatives, but that's no reason to give up on software freedom.

I think your advice is misplaced. Please try to understand the constraints we're working with instead of pretending they don't exist. Or at least, understand that if they don't matter to you, they still matter to our developers and many of our players.

What it seems to boil down to is that Epic Games are releasing a game engine and dressing it up as a kindness to the world, when in fact it's just another way to make money for them. They want people to make games so that if they are in luck and it does well commercially, they can reap the benefits in the form of royalties. Is that a somewhat accurate description?

Eeh, that's Stallman's way to look at it

Epic makes top of the line engine and let you use it for free to release free games or commercial games. Obviously they get no profit from free games.

They do get 5% royalty from sales of your commercial game if sales exceed certain amount. So in other words your game needs to be quote successful in order for Epic to get paid.

They also have custom licenses (for AAA companies).

Don't forget you get free engine and you can make a game for PC/Mac/Linux/Android/iOS/PS4/XB1.

Regardless, it's not GPL, so no matter how good it is to 2M+ of developers (majority of which are indies and students) you FOSS people will still condemn it

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Yes, i think its pretty much like what Valve does - instead of making their own games and selling them they just sell others people's games.

Valve is a distributor. Epic isn't.

Valve provides engine (which is much crappier than UE4, but more mature and tied into Steam) and distribution platform, while Epic provides engine only.

Also, Epic has 3 games in development.

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Please try to understand the constraints we're working with instead of pretending they don't exist. Or at least, understand that if they don't matter to you, they still matter to our developers and many of our players.

Self-imposed constraints, but I understand. That's why I keep saying Xonotic is better off with the same engine (or that engine, Unvanquished uses, being adopted for Xonotic's QC VM) and not jumping around. However, people who work on Xonotic and want to dump DP, could easily go with UE4, if they are not bound by self-imposed FOSS constraints.

And id Tech 4 is a bad choice for Xonotic either way

Well, we should just call Illfonic maybe , or we should just make our own Engine.

So, I registered to reply to this.

Motorsep is mostly right.

Of course, if you guys choose to keep that GPL free-software thing as a kind of dogma, it's your good right. Of course that seriously limits your options because game development as a whole is moving away from that. Porting to another quake-like engine is, humbly speaking, a waste of man-hours. The engine is not even your main problem.

Respectfully, I opine that the lack of a distinct art direction or unified artistic vision is what's hurting you. Your maps and textures aren't bad per se, but they look like a jumbled collection of different ideas. This is a thing that's hurting the perception of the game more than whether it has awesome offsetmapping. You're looking for the problem in the technical field instead of in the art, art direction, game design and presentation fields. Technology won't really help you make the game look better. Having a unified artistic vision and pruning everything that strays from it might be more worthwhile.

I have often tried playing your game, and I'm still not sure what it actually wants to be and how it wants to present itself.

Also regarding darkplaces, it might be helpful to get on the good side of its original developers again... work is still being done on it, games are still being made on it. Some humble pie might be required, but man could it pay off.

/Respectfully

kneedeepinthedoomed

I have often tried playing your game, and I'm still not sure what it actually wants to be and how it wants to present itself.

kneedeepinthedoomed

Well majority of the servers are modified and not many people play Vanilla 1 because there are not that many NA players and 2 lots of players like Minsta+Hook which is totally different than vanilla weapons play.

I don't see the point of switching to another engine when the game is only a few release from 1.0.

For the record, NetRadiant is fully compatible with importing meshes and props in standard .obj and .ase formats. You can even use animated formats such as .md3 and .iqm, provided the engine supports them.
All models lack vis though, and so shouldn't be used for too much of the main structure of the map.

As for the whole GPL vs non-GPL thing; This is all heading towards a war between open source freedom and commercial success, and is all off topic to what Xonotic and its developers are capable of.

DarkPlaces may still receive a minor tweak from Havoc once or twice a year, but this is hardly enough to keep the engine alive, or working well enough to support Xonotic. divVerent has kept it functional for now, but we're basically beating a dead horse.
Daemon has active developers working constantly to make it a better engine, all we'll need to do is keep it compatible with Xonotic's requirements, probably via a minor fork if any changes are unacceptable by their team.
The cleaner code and better language of Daemon's may also encourage more developers to support it as it becomes more of an open engine for other games.

kditd, let me stress this again: software freedom matters to us. I don't know what you are trying to do with your charged language -- you are calling our free software ideals a "dogma", why not a philosophy or a movement? -- but it serves to show that you are misunderstanding one of our core values. Of course we could make it so much easier by breaking free from free software (eh) but this free software thing is how we work. And as Mario points out, that is not today's debate anyway.

I appreciate the rest of your comment, though.