Blueprint library finishing touches kovarex At the time of writing the Friday Facts last week, not all of the planned changes were finished, here is the finalisation, so here we go.

We've been updating, reworking and redesigning many graphics, and the majority of entities have had high resolution for a while now. With 1.0 we're trying to be as "complete" as feasible.

The launch party Klonan To celebrate the launch of the game later this summer (only 6 more FFFs to go!), we have decided to throw a party! It is going to be at the same venue as our 1 million sale party (FFF-192). It will take place on Friday the 4th of September, 2020, at Žluté Lázně here in Prague. We are inviting a lot of people to the party, such as other Czech game developers, Youtubers, and of course we will be there. As we want you (the fans) to be able to come, we have some tickets for sale. The reason to sell them, rather than give them away, is so that we don't have 'messers' saying they will come when they don't intend to. You can buy a ticket here. While the COVID-19 pandemic might be 'over' here in Czechia (Czechs hold 'farewell party' for pandemic), the reality is, the situation could change with great speed. It is likely many won't be able to come due to travel restrictions, or we may even need to cancel the event. Please keep this in mind while you are considering whether to come. We hope everything lines up in our favour, and we look forwarding to meeting you.

Environmental particle effects Dom Since the particle optimization we did for 0.18 (FFF-322) and the introduction of new explosions (FFF-325), we were able to push our vision even more. It always bothered me that the grenade and other explosions would emit the same type of particles regardless of the context. In most cases it isn't that bad, and somewhat okay, but when you throw a grenade into water, it will still emit stone particles, which breaks the illusion. Another problem is that we have the nice decoratives on the ground, but they don't really 'interact' with anything that goes on, and can feel like fake flat stickers instead of something 'real'. You would expect that when there is a massive explosion 2ft away, the bushes might have some reaction to that. The explosion effect currently in 0.18

Statistics GUI Klonan, Oxyd The statistics GUI (electric network stats, production stats, etc.) is one of the GUIs that has been in the game for a very long time, and has had its functionality fleshed out reasonably over the years. It was not long ago when Twinsen added hovering and highlighting to the graphs. Given that, and the relatively short timeframe for 1.0 release, the update of the statistics GUI has really just been a style update, no new features or heavy logic rewriting. Oxyd has most of the work done, so we are happy to show some real in-game screenshots of how it looks: A notable change with the electric stats is that the Satisfaction/Production/Accumulator charge are next to each other in a single row, as opposed to each in a separate row. The label for the exact amount has also been moved to inside of the progress bar, which itself is much thicker. The production stats are pretty much the same functionality wise. One new button you might spot is the search button. However there are some problems with the search feature. As you can see, production and consumption frames have a different search box independent from each other. The main problem is when pressing CTRL+F to perform a regular search: How do we know which frame to open? Of course this could lead to different solutions like the use of a cycle for the focus of the search, in which the second time you press CTRL+F the other frame gets the focus. Or both of the search boxes open at the same time but only one gets the focus. Or only one frame gets the focus and the other one works only by pressing the button. But let's face it, these "solutions" are not solid at all and create inconsistency in the main design. To solve this issue we decided that the simplest way to go is the use of just one search box on the header of the panel. This new location works as a general feature for the entire panel. One single search gives you 2 results, one on each frame. This solution is used in the new character window -to come soon- making it consistent with the whole design of the GUI. You can also see we took this opportunity to integrate the Kill statistics in with the rest, instead of being its own window with its own hotkey. The Statistics GUIs will need a few tweaks and polishings here and there before it is ready for release, but unless something unexpected happens you can expect it coming out in a release soon.

Poison cloud Ernestas, posila The poison cloud animation is a placeholder spritesheet (that kovarex found somewhere on the internet), we have wanted to improve it for a long time, but since it was always such a small detail other things took priority. Well now is the time to finish everything, big and small. Some of the problems we see with the old placeholder animation: The edge (where damage will apply) is not clearly defined The center strongly obstructs vision underneath the animation It breaks the perspective/height illusion with its very circular shape The new animation was done quickly and without the need of any large changes to the Factorio engine. This is the mindset we are in these days, use the engine features we already have to finish things quickly and without trouble, and we try to stop ourselves going crazy with more detail. The smoke capsule itself spawns a bunch of smaller dummy entities which do the smoke drawing, while the damage is kept consistent by only using the central smoke cloud to apply damage.

Hello, The year is wrapping up, and we have been hard at work finishing off some topics before we take our Christmas break. As you can imagine, releasing any new version of the game without a few weeks to do bugfixing wouldn't be wise, so you can rest easy this holiday period without the worry of a surprise 0.18 release.

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 :).

Hello, Another week has elapsed, which brings us another week deeper into the declining weather of autumn.

More remnants Dom, albert As for the conclusion of the topic opened in the FFF-288 we finally decided to go for a balanced solution in which the player can recognize what entity was destroyed and also walk through them. The solution of going up in the Z-axis is really attractive for designing the destroyed models, but it gives a lot of headaches to the game designers due its need of a bounding box. We are planning also a generic set of remnants for the modders who don’t feel like making the destroyed version of their own machines. Here an example of how a factory can look after a biter attack: These remnants are still a work in progress, many of them are not yet finished and we are planning more iterations with this subject. By now you'll find a sneak peek in today's release (0.17.36).