Rocket Science News

Hello, guys.

It was supposed to be another patch and I planned to release it last week, but some changes to the game required implementing missing features, some new features added more things to fix, some fixed bugs showed, that the game needs more changes and so on. I didn’t even notice, how all this work suddenly become an update.

I started dealing with the most common complaint: rockets are hard to control, especially in the lower atmosphere. It was pretty obvious, that reaction wheels alone can't handle it. So I needed to implement thrust vector control (TVC) for engines. While changing the angle of engine’s nozzle was simple, a lot of problems appeared when I tried to add TVC to spacecraft auto stabilization system. The problem is that the torque, generated using TVC is much stronger, than if you are using reaction wheels. And it depends not only from engine thrust and nozzle tilt, but from the engine position relative to the center of mass of the spacecraft. Thus I spent days trying to make stabilization system responsive, but so that it does not overshoot or wobble all the time. Only after I started to calculate all possible torque, that engines can generate, I could send correct values to PID controllers, that auto stabilization system uses, and spacecraft became more or less stable in the flight. As a result you can finally start to make gravity turn pretty much at any moment if you have enough engines with TVC and positioned them correctly on the spacecraft.

Such turns and stabilization after it would be impossible without TVC on that altitude

After that the second problem immediately arose. Because of how camera is locked on the rocket and since there are no other references in the flight except spacecraft itself, there's the illusion that the center of mass of the spacecraft is located at the camera focus point. And since the rocket is turning pretty fast right now, it was painful to see. So I rewrote camera targeting system and now it focuses at spacecraft CoM by default. And you can switch it to any rocket part or move along the spacecraft during the flight.

The top of the engine is in the camera focus right now. And there is an illusion, that CoM in that point too

There are a lot more, that I did during the past two weeks (like velocity and orientation markers on navball, oh yes), but you can read about this in the update notes bellow. A small note about this update. I’ve tried to not introduce breaking changes to the game, so your save games should work, but all the spacecrafts you’ve created will not receive new features like TVC or changed stabilization parameters. So it is better to create the new ones. Also some new key bindings could be missing because of how controls settings saving are working. So it is better to check it or just reset controls to defaults.

Now I want to tell you about future plans a bit. The next most important features are: the Moon landing, improvements to orbit system, maneuver planner and symmetry tools for rocket construction. While the Moon are almost there (I need to fix a bunch of bugs and prepare textures for it), other systems are pretty big. Also I need to rewrite a mathematics simulation (when you are on orbit and engines are turned off) a bit, because I created it almost a year ago and it does not properly support a lot of new systems that I added later (like electricity, or checking spacecraft collision with the planet surface). Because of that I have currently no ETA for the next update, but I hope it will be in April and it definitely be huge.

That’s all for now, I hope you will enjoy this update!

[h2]Changelg[/h2]
Features:

• added engine trust vector control for all engines except "Zarya-352" Liquid Fuel Engine;
  
• autocorrection system uses engines to turn spacecraft if TVC is available;
  
• added thrust limiter to engine window (previously it was just throttle with wrong name);
  
• added velocity and orientation markers on navball;
  
• you can remove parts using Delete hotkey in Assembly Shop;
  
• you can toggle auto stabilization using T hotkey;
  
• you can switch camera focus to any rocket part in the flight using ALT + left mouse button click;
  
• you can move camera along spacecraft using ALT + mouse wheel;
  
• you can reset camera focus to default position using ALT + C;
  
• the Moon can be seeing from the flight camera now (but it still not reachable yet :/ );
  
• added "remove spacecraft" and "enter into flight" buttons to the list of spacecrafts in the Control Center.
  
• new part category "adapters" in assembly shop;
  
• new connector type "rectangle".
  

New parts:

• basic fin;
  
• advanced nose cone;
  
• adapter 1.2m radius to 0.55m;
  
• adapter 0.35m radius to 0.55m;
  

Changes:

• flight camera will focus at spacecraft's center of mass instead of command pod by default;
  
• to be consistent with the flight mode, hotkeys in Assembly Shop were changed:
  
• - focusing camera on the part is ALT + click now instead of SHIFT + click;
  
• - moving along the building is ALT + mouse wheel;
  
• some parts was moved from decouplers category to adapters;
  
• improved connector/slot selection during part attaching in assembly shop.
  

Fixes:

• planet generation memory leak when orbiting around Earth a long time with in the time warp;
  
• one of the fuel tanks has incorrect connection position, which lead to rocket flip over;
  
• one-socket part can be incorrectly connected to triple connector part;
  
• rocket part outlines stays when switching to map;
  
• lightning artefacts on Earth on map view;
  
• parts sometimes stay connected to the rocket after removing;
  
• new part is not selected from list, when another part was detached from rocket and stayed selected;
  
• bottom visual slots on side fuel tank are missing;
  
• decoupler and adapter attached to command pod have wrong alighment;
  
• engine turn on after changing throttle, even if it was manually turned off;
  
• missing alpha gradients from orbits;
  
• spaceport camera stop rendering if selected spacecraft was removed in control center;
  
• selected value in dropdown sometimes not localized properly;
  
• wrong engine name in the tutorial;
  
• click on detached part opens part's window;
  
• close button not worked in spacecraft stats window.
  

Known issues:

• sometimes rocket receives huge side force on launch (need more evidence to solve this one). If you encounter this, you can try go to Control Center and remove any bugged spacecrafts.
  
• it is impossible to reattach part with socket from one connector to another (you can detach part and place it before attaching to another one as a workaround);
  

Hello, everyone!

I've got a small patch to fix a number of bugs. I've improved UI a bit and added more settings to the game, as well. It was a rough launch, but your bug reports and feedback are very helpful, thanks a lot!

Features:

• added fuel amount indicators to stages;
  
• added three more connection variants for "Heavy" Fuel Tank;
  
• new options category "Performance", where you can change:
  
• - planets surface level of detail;
  
• - planets collision mesh resolution;
  
• - camera collision mesh resolution;
  
• - maximum number of parallel physics worlds (every active spacecraft uses one world).
  
• added sensitivity settings for assembly, map and flight cameras (Options -> Game);
  
• two new auto stabilization modes: radial in and radial out;
  
• new "reset rocket position" button in Assembly shop. It will reset Y and Z axis of spacecraft, retaining value of X axis.
  

* because of many crashes during rocket launch, planets surface LOD was set to "medium" by default. But if you had no problems with it earlier, you can switch it back to "high".

Changes:

• Assembly Shop was increased in size;
  
• settings are saved not only on quiting the game, but when closing options menu too;
  
• changed how all cameras process the input in the game;
  
• part category filters work like a toggles in assembly shop now;
  
• camera will no longer change position when rocket part was detached.
  

Fixes:

• memory leak on planet generation on some PC configurations, which lead to crash in some cases;
  
• spacecraft spawned in the middle of nowhere in some cases;
  
• spacecraft stuck on launchpad and persist during next launches (I don't think I found all possible scenarios tho);
  
• navball is not updating on the map view;
  
• time scale changes unpredictably on switching between physics and mathematics simulation;
  
• solar panels retract, when switching to map view;
  
• rocket stuck in assembly shop, when returning to the list of rockets and reset changes for the edited one;
  
• auto stabilization turn off when switching from another mode;
  
• rocket parts doesn't position correctly in Assembly shop, when the camera is close to the rocket;
  
• "pass resources" doesn't work for decouplers in some cases;
  
• save button doesn't appear, when the changes was made to rocket stages;
  
• rocket stages doesn't reset when reset rocket was pressed;
  
• spelling errors in the tutorial;
  
• some strings are not localized;
  
• one of the engine sounds doesn't loop properly;
  
• wrong tooltip on spacecraft stats button;
  
• changes to game controls is not saved between the sessions.
  

Known critical issues:

• game sometimes stuck when rocket exits atmoshpere on some PCs. Still investigating, need more logs to find a problem.
  

That's it, the game is out in Early Access!

It was a long journey from a simple rocket arcade to full-featured space simulator. But I want to share current state of the game before telling you about last 20 days from the last update.

The following features are available in the game now.

• Persistent sandbox mode that retains your launches.
  
• 51-step tutorial that will teach you all the basics of the game.
  
• Assembly shop with 25 rocket parts in it, 10 of which have additional configuration.
  
• Slot-based rocket construction system, which is easy to learn, but hard to master.
  
• Flights with realistic physics, aerodynamics simulation and orbital mechanics.
  
• Earth in real scale to explore. This one is generating using NASA elevation maps, so it is possible to find a place where you actually live in the game.
  

The game is generally stable. It still rarely crashes, but I haven't found a way to consistently reproduce this bug. So it would be great, if you could help me with it.



What is currently missing, but will be added in the next updates:

• Flight planning mode with time rewind. Unfortunately, I couldn't make it good and stable enough in time, so I disabled it.
  
• Saving presets of connected rocket parts.
  
• Bulk operations and symmetry tools in the Assembly shop.
  
• The Moon. This one is technically in the game, but it is unreachable without planner.
  

As for the last 20 days it was really hard. Most of the time I've spent making tutorial and fixing tons and tons of bugs. I literally fixed more than 70 bugs during that time. But this wouldn't have been possible without intensive playtesting. Thanks @gmhs, @irony, @icxon and @forsist for bug reports and feedback.

Here is also some interesting stats about the game development:

• I started to track development time in January 17, 2019. Since then I've spent 2280 hours making this game. And five more months before that.
  
• The project size is 41Gb without Earth and Moon elevations maps which add 15 Gb more.
  
• I've made 1736 commits into game repository.
  

And this is only the beginning of a long journey to creating great game. Thank you for being with me all this time and see you in the next update.

Greetings.

It’s been a while since the last update and I have a lot of things to discuss today.

I spent more than a half of December preparing the trailer and establishing art and content pipelines for it, which could then be used in the actual game development. During that time I created the first 15 rocket parts and battle-tested them by assembling different spacecrafts. The first thing I discovered, that direct controls over the spacecraft is a must-have feature for the game. When you are assembling rockets, you usually want to have a quick iterations over your design. This means that the time between attaching the last part and launch must be kept to a minimum. With the flight planning workflow this was not easy to achieve.

But before diving into flight systems I had to solve one important problem. As you you may have noticed from the trailer, I greatly increased the planet surface details.

Before

After

This was necessary not only for aesthetic, but because you simply can't feel the planet scale and size of spacecrafts without them. But performance immediately dropped from stable 60 to 40 FPS with such level of detail. This was unacceptable and I needed to rewrite planet generation system, using different, data-oriented approach. It took me five days and it was not easy, but, amazingly, the system has become simpler, more extendable and more performant. I hit target 60 FPS on my hardware (which is 5.5 years old) and created a good foundation for future grass, rocks and rivers systems. Also I will expose the planet level of detail setting to the players.

Then January has come and I finally started internal playtesting. The first system that got hit, was rocket assembly. While the main concepts were clear to players, available tools were terrible. Parts usually were not placed where users wanted them to be, connections not working half of the time, sometimes saved rocket even not load after all that. So I wrote down a long list of issues and spent next 10 days fixing them all. The system still lacks a lot of features, like symmetry tools or batch operations, some parts attachments are less stable, then others, but the core is now rock solid. Even I started to feel more satisfaction while designing spacecrafts.

A bit rough but it is correctly positioning itself on slots

It was January 11, 40 days before release. It became obvious that I will unable to deliver all three main parts of the game (spaceport building, rocket construction and space flights) with the same level of quality and comparable amount of content. And I couldn’t delay release even further, because then I need to find a job to pay my bills. And this means only part-time development on weekends and evenings. Which is extremely hard and would greatly increase development time. So I basically had two options:

1. Deliver everything with tons of bugs, little content and basically unplaytested (because I will have no time to fix all found problems).
   
2. Cut one of these systems on release, and concentrate more effort and development time on others.
   

The first option is bad across all levels. You want to launch an Early Access title, when you could gather a valuable feedback from it. There will be no such feedback when the game is just broken. Also it will spoil all game systems and it will be much harder to surprise players with the next updates.

Basically, I had only second option. But the problem was that you can’t cut rocket construction without cutting space flights, so there was a choice only between the space flights and spaceport building. And looking to the results of survey from the previous update, the choice was pretty obvious:

I hear you loud and clear.

There is only one thing that bothers me: now Elon will be in the same field with the giants such as KSP and other space sims. But they had so much more time to come to what they have now. Also it is very difficult to cut parts of the game you've put so much effort into. But I had no time for worries and regrets, I needed to get done the remaining systems. Here is a list of things I’ve worked on the next 20 days before this update.

Direct controls. Yes! It is finally in the game. There were two problems that I faced: how to make a rocket staging and how to befriend a rocket auto stabilization system with the direct controls. There was nothing new I could add to staging, so it will look like in other games:



The auto stabilization system is now understanding player input and didn’t try to alter the input axis.

Rocket design flexibility. Before the total assembly shop rework, part connections were very strict. For example, rocket engines could only face down. Now you could connect parts however you want, until the rule “every connector should find it’s slot” is being fulfilled.

Game: you can build any spacecraft you could imagine. Me:

Engine fuel. I've redesigned the architecture of engines so that in the future, there may be several types of fuel pairs in the game. Right now they consumes UDMH with nitrogen tetroxide. This is small change, but I love when the systems have a good foundation under them.

Explosions. That’s right. At the beginning of January all rockets were undestroyable. And now every part has an impact tolerance. If the collision force became too high the part will explode adding explosion force for all nearby parts. I think, you can even launch something into space using only explosions.



Sounds. I record all sounds that can be recorded at home using the equipment I have left since my film-making hobby. Other can be found on freesound.org or in my personal sound library.

My sound recording equipment

There were hundreds of fixed bugs and much more small, but valuable improvements, but you will have a chance to discover them by yourself.

Now I have only 20 days left and long list of features I want to implement before release. Every day I look at this list and sort all the features, so only the most important will stay on the top. Besides that I need to create and add new rocket parts into the game, continue internal playtesting, prepare and send build to Valve, order game localization, write next developer update and much, much more. Every developer says that the game is shaping into the final product in a few days before the release. Now I've made sure of that, too.

To summarize, what does it all mean for the game? There will be only sandbox game mode available on release, where you could assembly spacecrafts and launch them into space. You will be able to directly control your rockets as well as launch them using flight plans. More info, such as how many rocket parts will be in the game or what celestial bodies will be available for exploration, I will publish in the update a day before release. And spaceport building and a lot of other cool stuff will come in one of the following big updates for the game.

I hope you enjoyed this update and see you the day before the release in Early Access.

I’ve happy to announce that the ‘How do you like it, Elon Musk?’ will be released in Early Acces on February 20th, 2020. Also the trailer is finally here. A year and a half of hard work is in this one-minute video. I hope you will enjoy.

[previewyoutube][/previewyoutube]