Hello, this week wasn't easy, I spent most of it in bed, drinking hot tea and trying to get healthy. The rest of it was spent by cooperation on the release preparations, which basically means bugfixing. Yea, and I also had to do the first steps of my wedding preparations, oh didn't I tell you? Now you know :)

Hello, We had a lovely surprise waiting us this Monday, one of our fans had sent us a delicious cake: It didn't last very long... Thank you very much Conn! It certainly helped with the bug fixing push this week.

Taipei Game Show 2018 (Twinsen) After a long 14 hour flight back, Albert, kovarex and I arrived back from Taipei, after our attendance at the Taipei Game Show. Jitka started her vacation by staying there to visit the Taiwan island. We stayed there for 7 days (2 days in the business area, 3 days in the convention area and 2 days of free time where we visited the city). In the business area we met many potential business partners and got way too many business cards. We made some friends among the other indie developers and tried all kinds of fun, weird, interesting and some bad indie games. The convention area was very crowded, with 350,000 visitors slowly trying to make their way through the fairly small convention hall. I can't speak for the others, but I still enjoyed myself. Even though it was crowded, most of the games were in Chinese, and I only got to try one AAA game, there is something about being surrounded by games, gamers, and game developers that makes me feel great. Our booth was in the indie area. We had many people coming to try the game but also many fans wanting to speak with us and congratulate us for making a great game. AndrewIRL who lived there for a few years, invited us for dinner to "the best restaurant in the city", and we were not disappointed. Factorio is not an easy game to demo, since it takes at least 30 minutes to kind of understand what the game is about. But having the trailers looping on the screen, and having subtitles for the gameplay trailer meant that the people got a fair idea about what the game is about and how complex it is. While not the best, we had people start by playing the campaign. Most of them were leaving after the first level but some of them were also getting addicted and playing for multiple hours. We gave free Steam keys to some of the people who were more engaged with the game. It was a learning experience to see people play the game for the first time and to see the most common problems with the campaign, the interaction, the UI and the Traditional Chinese translation. The days were super exhausting though, many of us collapsing at the accommodation and sleeping for 10 hours. Luckily we had 2 more days to relax and enjoy the city before flying back. We mostly split up and each of us visited what they were most interested in, with me going through the electronics markets and riding a rented bike through the rainy streets. To give credit where credit is due, I'd like to thank the game show for inviting us and sponsoring our booths, and Razer for conveniently lending us the laptops we used to demo the game. Financially there is no point in us going to a game show, our attendance did not bring us any extra sales in Asia, as expected. The point of going there, for us, is to visit the show floor, play and see random games, make gamer friends, meet fellow developers, meet big fans of the game and maybe make some business partners. Since many of you mentioned PAX and some of us are interested in going there, we are trying to see if we can attend PAX East this year (April 5-8th). So you might have another opportunity to come and take selfies with some of the Factorio devs. From left to right: Jitka, Albert, Twinsen, kovarex.

The beacon is one of the last entities left to convert to HR. As always, before 'just re-rendering' we take the chance to re-think the concept and modernize it. This post will try to go a bit deeper in the process of redesigning such an entity.

Electric mining drill redesign Ernestas & V453000 The electric mining drill is one of the older designs still in the game, and we have had our eye on it for a long time as a candidate for redesign. We would have loved to rework the mining drill in 0.15 when we added high resolution graphics and the pipe patch for it, but we had many nuclear related graphics to do for 0.15, so we just did the necessary minimum and postponed the full redesign. Now was finally the time we could unleash Ernestas onto it.

Hello, we have shown some bigger things recently, so it is time to also show some smaller things, because the bigger things wouldn't shine that good without the smaller things working properly!

Fluid mixing saga Dominik Hello Factorians, Today I would like to talk to you about my favourite subject - fluid mixing and its prevention. It is a new mechanic introduced in 0.17 that seemed quite simple at first, but has been giving me nightmares ever since. A while ago I took on the task of updating the fluid system (FFF-260). The way it works in 0.16 is that the fluid boxes (the thing that holds the fluid and is contained in entities like pipes or refineries) had no organisation whatsoever except their connections. They would sit there and do nothing and then once per update send fluid somewhere. It had it's issues especially with symmetry, and when you happened to put some fluid where it did not belong, you could end up requiring major demolition works. My task was to develop a better algorithm to move the fluids, and a very very optional side task I had in mind was to do something about the fluids getting to wrong places and mixing. We started by organizing the fluid boxes into systems (connected FBs make a system) managed by a special fluid manager, and optimizing the heck out of it (FFF-271). Soon after, I started working on the new algorithm and anti fluid-mixing. Until then nobody really considered preventing the fluid mixing seriously as it did not seem possible. But when I thought about it, it did not seem that hard. The idea is to simply not allow any action that would lead to fluids getting where they are not supposed to go. When you build a steam pipeline, you should not need nor want it to touch another fluid. In principle, it would only require a few quite realistic mechanisms: A connected block of fluid boxes would either be fluid-free, or it would be locked to one fluid. Two such blocks can connect only if they are compatible - either one has no fluid lock, or they have the same fluid. An assembler can only set a recipe if it is compatible with the fluid locks on its fluid boxes. Have a migration from old saves that can contain mixing. By creating the fluid systems right before, number 1 was almost finished and we only needed to assign the lock. It would be set either by a fluid, or by a 'filter', which is a fluidbox that is set to use a fluid - such as a water pump using water, or assembler having some inputs/outputs given by a recipe. After a while I had both the fluid algorithm and the mixing done (FFF-274). The mixing was not that easy (like 5x more complicated) but it worked pretty well. As for the fluid algorithm, V453000 and Twinsen found some issues with waves on a macro scale, and because it was right before releasing the 0.17 experimental, we decided to hold it off on it for the time being (we have a new version now that seems okay, but has to wait for 0.17 becoming stable first). The mixing made it through though and seemed quite finished. It turned out that the work on it was at most one tenth complete. Some difficulties appeared already before the initial release, but that was only a hint of what would come later. One by one, then ten by ten, bugs started coming. The problem is that as often as not, they were not just little issues with simple fixes. Instead, over and over, they turned the current solution on its head and the code had to be completely rewritten in order to account for the new case. As of now, almost exactly half a year and many rewrites later, it is still not fully bug free. The number one issue was with Assembling machines. It turned out that their code was pretty messy and does not simply allow the checks I needed, so it had to be refactored. The next problem was that the check was not only required when setting a recipe on an existing assembler - as I naively thought - but in about one million different situations I would not dream existed. Building a fixed recipe assembler. Reviving an assembler. Rotating. Blueprint of an assembler. Blueprint with a recipe and a rotation placed over a ghost with a non-default rotation during a full moon. Teleport. Script building. Copy-paste settings. Any combination of these. Pretty much every case would go through different paths in the code and behave entirely differently. Fixing one would break another and so tons of tests had to be written. When these cases finally worked, it turned out that doing these operations when they fail (e.g. can’t rotate because it would cause mixing) brings another wave of issues. And then mods come and the complexity multiplies. All this, although in a more simple form, had to be done for all other entities that can use fluid too, such as inserters (mods...). Another number one issue are underground connections. When playing, you would not think twice about them but on a closer look they are all but simple. They have this (cough) uncomfortable feature (want to shoot myself) that you can build another underground pipe between them (or take it out) and a complex reconnection logic jumps in. It means that based on building order, connections are established and reestablished differently. This is a big thing when building a blueprint with many pipes, or loading a save game. But the largest issue is one tiny corner case with huge implications. Have two underground pipes that have different fluids, but are split by a third, and it gets removed. Until now mixing was theoretically completely avoidable, but here it was and there was nothing to stop it. As a result, a new concept is introduced - a blocked connection. An underground connection that would normally connect but can’t. Establishing it is the easier part. But when does it get fixed? An entity miles away gets rotated, that splits a fluid system, disconnecting the blocked connection from a fluid filter on the other side, and the connection should unblock. But even something as simple as a rotation contains fluid fixes and re-establishing of fluid boxes and if it fails, it still fixes the blocked connection in the process and it can’t be undone... You get the picture. And we are still talking about underground pipes, while anything can have underground connections, including said assemblers, which the previous code did not consider at all. The complexity just goes deeper and deeper, and Rseding is probably right that we should have never gone this way at all. So the bug fixing has been basically running in circles - clearing one batch of bugs, thinking that those were the last ones and the ordeal is finally over, only to find another batch (ideally from some bizzare modder idea) a few days later. Many times I wished that mods never existed. Nor multiplayer, or any players at all for that matter. About two months ago all seemed really fine, with basically no reports and just a few crashes in the automated crash reports. At that moment another nightmare materialized in the form of a talented volunteer bug tester named boskid, who took on a personal crusade to break the fluids to dust (I actually imagine him sitting in his dark room with evil laughter, dreaming about making my next day worse than the previous). In all seriousness, he has done a great deal of work with his bug testing, creating bizzare modded cases and testing scripts, and deserves a big thanks. He is actually coming to our offices next week, so follow the news for reports of developers falling out of windows. An example of a nice configuration he found (and I can’t fix). The whole time we were taking the offensive approach to mixing - crash the game when it happens - so that we know about bugs to fix them. Recently we have decided to put a stop to it and have the mixing automatically fix itself once it is detected, eyeing the end of this episode. Right now I have 3 mixing bugs on the list and I am sure those are the last, and mixing will be done (lying to myself is a way to cope with it) and the new fluid algorithm can come soon after :).

The main menu rework Twinsen Up until I looked at the source code, I was always confused about the differences between "Start campaign", "New game" and "Scenarios". New game seems like the same thing as "Scenarios"->"Freeplay", but are there any differences? We then later added a few more bonus scenarios, but they are hidden in the scenarios menu, with no explanation about what each is, what to expect or if it works in multiplayer. I believe it's very important to communicate to new players information about the game's content. It's also important to show that freeplay is the intended way to play. So all this prompted me to rework the main menu a bit. I started with the structure. The structure always seemed odd to me, compared to what I'm used to from other games. Important options like "Load game" are lost among options that are never used (like "Replay game"). So I came up with a new structure. It looks like this: Continue Single player New game Load game Multiplayer Host new game Host saved game Browse public games Browse LAN games Connect to address Map Editor New scenario Convert save Settings ... Mods About The first new thing to notice is the "Continue" button. Since "start the game and continue my last save" is probably the most common thing players will do, it makes sense that there is an option for this right at the top of the main menu. The button will contain the name of your latest save. Pressing it will immediately load the game and get you in game. Due to implementation complications, for now it only handles save games and it will NOT connect you to the last server you played on if your last play session was multiplayer, but I might implement that if it's highly requested. Next, everything was grouped into either Single player or Multiplayer. There are much fewer options, since "Replay game" was moved as a small button in "Load Game", and every way to start playing the game was moved to the new "New Game" GUI. The "New game" GUI shows all the ways to play the game. It also groups them nicely, places freeplay on top, shows a description and even a nice image. This GUI is used for new game, multiplayer hosting and map editor, thus simplifying the menu quite a bit. For modders, scenarios can now contain a description.json file. In the file "order" determines the sorting in the New Game GUI; "multiplayer-compatible" determines whether the scenario is shown when trying to host multiplayer games. "multiplayer-compatible" was added to description.json file of campaigns also.

Hello. With Christmas nearly upon us, life in the office has slowed down nearly to the point of complete hibernation. But we still bring you your scheduled programme to give you something to look forward to in the next year. For the past few weeks, I've been working on our shiny new blueprint library. We already introduced the library in FFF 161, but to briefly recapitulate: The blueprint library is a place for you to keep your blueprints, and it does two things for you: Blueprints that you save in your library are saved on your computer, and when you load a new save, those blueprints are still available in your library. In multiplayer games players can see each others blueprints and can exchange them easily.

Steam Awards (Klonan) Steam has opened up the nominations for this years Steam Awards. Last year Factorio was actually selected as a nominee for the 'Haunts My Dreams' award. There is a category this year for 'Best Developer', and many in the community have wanted to nominate us for that category. Unfortunately to be eligible, we would need to have a developer page set up on Steam. We had some discussions, and decided to wait until we have a final 'Wube Software' logo and theme finalized before setting up a developer page. This means you won't be able to vote for us as best developer this year... This doesn't meant that you can't nominate Factorio for one of the categories, and there has already been some discussion on the subreddit about which games people are voting for.