Good afternoon, the work on 0.12 are continuing quite well according to the updated roadmap presented in the previous facts. So this is a good opportunity to talk more in depth about one of the upcoming improvements for the Multiplayer - how we plan to deal with the latency.

Hello and Merry Christmas, there are no holidays that stop us from informing you about the progress of Factorio development, so enjoy :)

Hello hello, I hope that the powerful constellation of Friday the 13th has brought you good luck or at least good humour. We have seen quite sharp decline in some Factorio related statistics in the past days so it seems that the AAA titles invasion starts to be felt ... many of you playing Fallout 4?

Hello Factorio players, lets start our developer to player interaction right now! :)

Tile transition collisions Klonan We first mentioned a change to our tile transition logic back in FFF-199, and not long after in FFF-214. These two posts focused more on the visual side, and how it makes the game terrain look so much better. In short, the tile transition logic overlays an additional sprite over adjacent tiles, so that where the two tiles meet has a much more natural look. Left: Tile transitions on; Right: Tile transitions off. So while the looks were taken care of, we also had to deal with the 'feel' of the tiles. The easiest example of this is the 1x1 landfill 'stepping stones'. It really looks like you should be able to walk/drive across the 1 tile of water. So we added in an additional layer of collision checks, which will consider the transitions when performing the logic of what can go where. Now some of the cheesier among you will know that biters don't know how to get across these 1 tile gaps. That is because simply we never enabled the biters to use this collision check logic. One reason is that more checks means more UPS usage for the biter pathfinding, another is that we didn't think it was necessary. However it was available in the engine, and any mod could enable it if they want. That is exactly what I did with my Mining drones mod. Initially this seemed to work, and I thought it might make them walk around lakes a bit more naturally (like the player character does). However quickly I noticed that people were reporting on the forum that the game was crashing with the mod installed. I quickly reverted the change to my mod and we started looking into it. It turns out that the new abstract pathfinder we added for better unit pathfinding (FFF-317) was not set up to consider units using this tile transition collision logic. This same crash was happening sometimes without any mods installed, but the case was more difficult to reproduce, so this is a nice situation where mods help us work on issues in the base game. Recently I have been working on another unit heavy mod, Transport drones, and the principle design behind the mod heavily relies on the tile collision logic (the units don't even collide with entities). It turned out to be a really nice test of our new pathfinder, but also highlighted some of the issues that not considering the tile transitions can bring. By not considering the tile transitions, the drone takes an awkward path along the diagonal road. This week Oxyd finished his work on an upgrade to the pathfinder, so we can enable the tile transition collision logic with units. The change is immediately noticeable with the above example. By considering the tile transitions, the drones path much more naturally. With the logic now in place, we are debating whether to enable it for biters or not. We probably won't, it is only a minor change and would have a non-zero performance impact (a rough test puts the worst case at about 5%), but then again it is a fun way to surprise those who thought the 1 tile of water would stop the biters attacking, and it kinda makes sense they can walk over it just as the player can. Well we will see if there are any issues with it in the modded cases before any further consideration. As a bonus fact (this is Factorio facts after all), I spent a bit of time benchmarking some late game Transport drone based factories (screenshot), and found a few nice performance gains.

New Fluid system 2 (Dominik) Hi Factorians, Here is Dominik, with an update on the fluids. This time it is pretty much finished so I can tell you facts instead of just speculations. You will find how the new algorithm will work and some new handy usability features. In FFF-260 I wrote about how it all started, why we are doing it and what the plan is. There was a huge response from you all and I want to thank everyone for their contributions. Let me apologise to redditors, as at the beginning I started responding on the forums and when I realized there is reddit too, there were too many comments for me to handle. The forum users produced many ideas on how the system could work. About third of them was a fluid teleportation, many where known but many were entirely new and interesting. What intrigued me was the large variety of backgrounds they came from - differents kinds of engineers (mechanical, CS, electrical, ...), mathematicians, physicists, and even people with real pipes hands on experience. I won’t go through them here, you can find them on the forums or reddit. There were two proposals on the forum though that were so good that they made it into the game - from quinor and TheYeast. Both of these proposals were very similar and kinda similar to the previous game logic. What it shares is that the mechanic still uses fluid physics simulation and volume in a pipe as a base for the movement calculation. As a result, not much changes on the first glance. What they add though is an emphasis on the fluid network update being independent on the current state (i.e. updating one pipe only depends on state from the last tick) and is therefore independent on evaluation order, which was one of the big pains of the old model that led to sometimes ridiculous junction behavior. Difference between these two was rather small - quinor’s version allowed perfect throughput with 3 passes over the fluidboxes (fluidbox is the thing managing fluids for entities, so I will talk about them), while Yeast’s one was 2 pass with ¼ throughput. What was outstanding though is that TheYeast, a physicist, supported the model with a nice theoretical background and what’s more, he made an amazing JS simulator to test and compare various modification of the model. Because that extra pass in quinor’s version was too high a price for the perfect throughput, I went with TheYeast’s two pass one. Since the old algorithm only used a single pass run by entities for the update, I first needed to overhaul the whole system to allow accommodating the new one. Going from one pass to two passes necessarily means higher complexity, so we made a big effort to optimize everything we could to make sure we will still end up faster than 0.16. Kovarex wrote about it in FFF-271.

Hello, today we will go over some of the details of Space platforms we couldn't fit into the last FFF, as well as some new features that will tie the whole system together.

Hello, long time no see :) We obviously have a lot to talk about when it comes to the game changes we recently did, or plan to do, but we don't want to share any of it yet. Yet, there is currently a topic very relevant to us and we can share it without revealing any specific changes to the game. Today's post will be quite technical and related to programming, so if you just came for the game news, you can safely skip this one.

Ladies (hopefully some) and Gentlemen, the 0.11.0 with first version of the Multiplayer has been released. The multiplayer experience is expected to be really buggy (as we learned today during a test with 4 players), but it is a first step. Oddly enough, our efforts haven't escaped the attention of a local newspaper which made an article about us - see the picture below.

Hello, Tomas is in India already, so the place is more empty again. The more empty it is, the harder we have to work to make for it :)