March 2, 2019

Bringing balance to the karts

The upcoming release of the next SuperTuxKart version is getting very close!

Several hundred players tested online networking with thousands and thousands of races. While it was already very playable, the beta helped to catch a few nasty bugs which are now fixed for the release, and to get gameplay feedback, as online races have a different balance compared to races with AIs.

But in this blog post, our main focus will be gameplay, with all the changes applying to both single player and multiplayer compared to 0.9.3. The basis of STK's gameplay remains unchanged: drive along the tracks while trying to drift and collect nitro, using items to boost yourself or attack other karts, but the next version includes many evolutionary improvements to enhance fun and balance.

First of the main changes: the kart classes have been rebalanced. People familiar with the previous versions may have noticed that heavyweight karts were useless, as they were equal or inferior to medium karts in everything. Lightweights were superior for abusing unintended shortcuts but otherwise worse.

Now, each kart class has different acceleration, top speed, nitro consumption, maneuverability... values which have been carefully tuned so that each kart class is best in some tracks and race conditions.

For example, the higher top speed of heavy karts is valuable in tracks with gentle curves and in time-trials, while lightweights fare better when maneuverability and acceleration after crashes matter. We have also improved turn radius, making sure all karts within a class behave the same and none is harder to drive.


The second main change has been improvements and fixes to track themselves. A huge amount of unwanted shortcuts and skips (some of them exploiting rescue) has been patched. This ensures that online races won't see players abusing such issues to beat others driving along the intended path, except one which has been left for adventurous players to discover.

Next, the locations of item boxes, nitro cans and bananas on many tracks have been reworked to enhance balance and fun. Too easy to catch big nitro cans (giving a big advantage to the player taking them first) have been moved or changed to small cans, and item boxes too close to the start line or to other item boxes have been moved or removed. On Volcano Island a few bananas have been added to enhance the challenge.



The third main change is a rework of slipstreaming. Slipstreaming is the speed bonus you get from being close behind another kart. In real life, the speed boost from being shielded from wind by another vehicle is small but continuous. In STK, it is cartoony : you are made aware of being in the boost zone by an animated air movement, and only activate the speed boost when you stop following the other kart after having been in the boost zone long enough.

In the upcoming release the air movement gets faster and its colour changes from white to yellow to make it easier to see when a boost has been charged. The slipstream boost has also been improved to provide a healthy max speed and acceleration boost, but more progressively and much less likely to cause the player to crash. The slipstream area where the boost can be collected is wider and longer. It is divided in an inner area and an outer area, if closer to the followed kart, less time is needed to accumulate the bonus. It is also much easier to collect boost in curves, so you can get the boost there too!

Finally, a deep rework of powerup probabilities has been done. While the set of available powerups is the same as 0.9.3, their distribution has been greatly improved in several regards.

Previously :
  • Karts were put in a group depending on their position, and each position in the group yielded the same item probabilities. For example, in a 12 karts races, 2nd and 4th had the same item probabilities.
  • The same set of weights was used from 1 to 20 karts.
  • Follow the Leader mode used the same weights as normal races.
  • Karts behind had a strong tendency of destroying each other with explosive cakes and other attacking powerups.

Now :
  • Each position get unique weights, by averaging weights between reference values. The item probabilities evolve progressively with the position instead of suddenly.
  • Several set of weights are used to account for the different dynamics depending on kart number. For example, the last kart in a 20 kart races is much more likely to get a triple zipper than the last kart in a 5 kart races. Values for number of karts between the reference points are interpolated. This is also used to better control the amount of global items (like parachutes or the swapper).
  • Follow the Leader mode gets customized weights.
  • While karts in the middle still attack each other more than they can attack the first kart, this is less damaging and bubble shields are available.


Cakes and basketballs are now unavailable during the 15 first seconds of a race. Explosion duration, whether from weapons, bombs or track hazards, have also been shortened, in order to make them less punitive.

In the long term, we plan to introduce new powerups in STK to make gameplay more varied and to overcome some shortcomings of the current set, but these changes shipping in the next release are a huge step forward.

To close up this blog post, let's mention several smaller changes, mostly quality-of-life enhancements, some of them already mentioned in earlier blog posts :
  • When doing a quick (yellow) drift after a long (red) drift, the stronger bonus of the red drift is no longer removed. Instead, it last until its normal end, and if the quick drift should end later, it will then take effect.
  • The startup boost requires to press the acceleration button quickly after "set" instead of "go". This change has mostly been done for online multiplayer as it allows the clients to better predict how other karts start.
  • Physics have been improved: karts are much less likely to be catapulted flying across the track after a strong collision against a wall or some other obstacle, and always remain controllable in downward slopes.
  • When nitro is consumed during the minimum nitro consumption time, the kart will always get the boost whether or not the player keeps pressing the nitro key.
  • Burning a tiny amount of remaining nitro (less than the normal minimum use) provides a shorter boost.
  • The AI is being smarter about how it uses nitro and items (which is more of an AI enhancement than a direct gameplay enhancement), and the way the AIs slow down in easier difficulties has been changed to be more forgiving towards players and to avoid all AI karts being very close to each other.

We hope you will enjoy these changes!

January 11, 2019

SuperTuxKart networking - 0.10-beta release

It has been around 2 months since we did our alpha release of the online racing implementation in SuperTuxKart. First of all a big "Thank You" to all the people who went through the effort of downloading and compiling SuperTuxKart themselves. They have provided very valuable testing and feedback for us, and as a result we have reworked some of the code to make it more user-friendly, and removed some bugs. I am also quite proud of our testing team: essentially no significant bugs in the actual online racing was found during the alpha - so a great job by all of our testers and coders! There was a tireless effort especially by Benau, Deve, and Alayan to constantly improve our code!

Also a big thanks to players who have volunteered their hardware to provide more servers for us. Even during the alpha we had typically more servers than actual players. Hopefully this beta release will allow more people to participate in online races.



We are now confident that our code is stable enough for a beta release: 0.10-beta1. This means that we will provide our usual set of binaries and installers for all supported platforms. And hopefully that means that many more people will be able to test this current version. Note that we consider this beta very stable, de-facto very close to a release candidate. But we are waiting for another track to be ready to be included, so we are using this time to give more players the opportunity to test (or re-test) our online racing implementation.

If you haven't read the previous alpha announcement, here a short summary of the new features in SuperTuxKart compared with the latest stable release 0.9.3:
  • You can now race against your friends or people world-wide in online races, either in LAN or WAN games.
  • You can either run a server on your own computer, all handled by SuperTuxKart, fire up a stand-alone server, or connect to servers already running.
  • A Raspberry Pi 3 is powerful enough to act as a game server (though you need a server-only binary). We provide several game servers on VPS and Pis that are constantly up.
  • On special so-called 'ranked servers' a global ranking of online players is maintained. You can see the current ranking here.


One important caveat: the network implementation is actually quite sophisticated (I might do a separate blog post about its implementation), but there are still limits in what we can do about the latency (or ping) between clients and servers. We strongly recommend to find a server with a ping of under 150ms for a smooth playing experience. The ping to the server will be shown when you connect to it. You can of course try servers with higher latency - while it should still work, you might notice more often that karts stutter, drive like drunk (though that might of course also be the skill of the other players) or are 'teleported' around. In addition you need a stable connection, so if you experience significant packet loss or jitter you will see the same strange behavior.



And new in this beta compared with our alpha (besides bug fixes and GUI improvements) is the possibility to now join a server while a race is in progress: you will become a spectator and can follow the race-in-progress. You will be joining the actual racing fun when the next race starts.


We have now pretty much declared a feature freeze to prepare for our release candidate, once we get the new track added. One noticeable difference to one of our release candidates is that we did not update all translations: this usually delays a release by two weeks, and we would like more testing to be done earlier. On the other hand, we hope that there won't be too many changes between the beta and the release candidate, and that we will soon be able to get onto the official release of online SuperTuxKart.



You can download the beta from SourceForge. Feedback as always is welcome, ideally on our forum, which is also the best location for support requests. Bug reports can be submitted to our tracker on Github. Note that bug reports and support requests here as a comment are not ideal, and might easily get missed, so please use the appropriate URL above.

We hope you are all going to enjoy SuperTuxKart with online races!

December 8, 2018

Refreshing the GUI

Online multiplayer won't be the focus of this new blog post : we will tell you more about it when launching the official beta in the coming weeks.

Instead, we'll tell you more about the many changes in the game's UI.


First, the kart selection screen now has a bar indicating the nitro efficiency of a kart. It is also now possible to hover an icon to display a tooltip reminding you what it means.


The help menu has been revamped, using a new UI element in STK, vertical tabs. Two new tabs have been added to the help, explaining the story mode and kart classes ; and additional information has been added to several other tabs ; like the skidding help shown here in the general tab.

The multiplayer tab also now contains help on how to access online multiplayer.


The track info screen now displays up to 5 highscores, and has a bigger track preview picture than before.

In time-trial mode, race results and highscores are now displayed to the millisecond, like in the ghost replay list.


The options menu has also been changed to use vertical tabs. As you can see, this has allowed the addition of two new tabs : a General tab giving a quick access to common options, mostly related to connectivity, and a Language tab, helping to switch SuperTuxKart's language setting with ease and freeing up space in the User Interface tab.



Two new options have made their way here, related to improvements and new features in STK : the option to control how the screen is split in local multiplayer, and an option to control the minimap display we'll talk about further in this post.

You may also have noticed that the difference between checked and unchecked checkboxes is now much more clear than in 0.9.3.

SuperTuxKart also now feature a new dark theme you can choose to enable.

Finally, the race UI has seen many enhancements : 


Please note that this is the UI for the regular computer version (Windows/Linux/Max), the Android version share some of these changes but keep touchscreen specifities.

All the texts now receive a black outline making them much more legible, especially in tracks where the color didn't contrast enough with white text. Some informational text, like the "final lap" message, now also uses a bigger font, while being put higher to not obstruct vision.

The speedometer and nitro gauge have received a major overhaul.

The maximum displayed speed by the speedometer is now significantly higher (40 instead of 30 previously, with 25 being the base SuperTux speed) in addition to increased accuracy. It won't be maxed out just because you did a skid or used some nitro !

The nitro gauge is now much more accurate, and slightly bigger. You can tell in a glance how much you have. This is especially useful for the nitro challenges, where the very uneven progression of the old gauge caused frustration.

The minimap's default size is now bigger, to help using it with a quick glance. You can choose in the options to display it on the right side above the speedometer, or to not have it displayed at all, according to your preference. The minimap is also displayed before the race's start, to allow players to take a look at it before racing begins.

Some other minor changes have made their way into the race UI, like the flag next to the lap counter to clarify its function, and the same flag used next to a kart icon to mean it has finished the race.

Many minor menu UI changes are also included in the next release, including :
- Many instances of text being cut (especially in translations) have been fixed
- A reset password button for easier management of STK accounts
- A donate button in the credits
- And more small fixes and quality-of-life improvements.

More fixes and enhancements may also make their way into the next release.

Finally, here is the new online menu with access to local and global networked multiplayer :


Expect more on this soon !

November 17, 2018

SuperTux challenges in Story Mode

SuperTuxKart's story mode has replaced the previous challenge system in version 0.8, introducing an overworld where the player can drive freely between challenges. This was in 2012, and since then, it had not evolved much.

New and better tracks have regularly been replacing old ones. There have been balance changes to have a more consistent difficulty level. But it fundamentally stayed the same.

In the next version, the current overworld will remain. Bringing a fully new one, up to par in quality with the latest tracks and making it easier to extend, is a huge undertaking. It will happen, but later.

There are, however, several exciting changes !

The most important one, long clamored for, is the introduction of SuperTux challenges.


Once you've unlocked the SuperTux difficulty, you will have access to an additional difficulty level for challenges.

Previously, the SuperTux difficulty was unlocked by finishing the story mode, no matter the difficulty you played at.

Now, the main way is to get a good number of gold and silver cups to have enough points to unlock it.

With stronger AIs, and more challenging time requirements, the SuperTux challenges will put your driving skills to the test.

Challenges in other difficulties mostly drop time requirements : you need to beat the AIs instead. The main exception are the challenges based on time-trial.


Another major change is an increase across the board of the number of AI karts to race against in challenges. In SuperTuxKart 0.9.3, races mostly had a total of 3 to 5 karts, including yours.

Now, and with some exceptions like the final race, the challenges will put you in 4 to 10 karts races. The number of opponents increases from the early challenges to those before the final confrontation with Nolok, ranging from 4 to 7 in Novice difficulty to 7 to 10 in SuperTux difficulty.

There are many other changes :
  • The GP challenges give three times as many points as single race challenges, instead of the same amount in 0.9.3.
  • The follow-the-leader challenge has been removed. It was very random, and didn't allow the player to make a difference by driving better as the speed of the leader was the limiting factor. FTL has been improved for the next version, but not enough yet.
  • Some more tracks are unlocked from the beginning of the game. But there are more karts to unlock : some of them can be obtained by completing a specific challenge, some others by attaining a total of points. One of them requires completing some SuperTux challenges.
  • The story mode now features a ghost replay challenge, where you're tasked to beat the time of a pre-recorded replay. The higher difficulties one can help you to learn how to drive better by showing you trajectories and how to make good use of skidding and nitro.
  • The chest unlock cutscene has been improved : now, it will show you karts you unlocked, and elements are better centered.
  • The tracks in GPs have been revised, in order to have easier tracks in earlier GPs and harder tracks in later ones. The last GP do not include Fort Magma anymore, fixing two issues which could occur : the last GP having only 4 races, or the possibility to race in Fort Magma before the final challenge. Instead, Candela City, which didn't appear in any GP in 0.9.3, is now featured in one.
  • In higher difficulty GP challenges, finishing 2nd or 3rd will award a cup of an easier difficulty. For example, being 2nd in an expert GP challenge will give a silver cup, while being 1st still gives a gold cup.
  • The possibility to access the final challenge earlier than intended ("gate skip") has been patched.
  • The nitro challenges now use the time-trial mode as a base, giving zippers at the start rather than mostly useless random items in the gift boxes. 
  • Bugs which could cause the game to return to the single player screen after the end of a challenge race have been fixed.

November 11, 2018

SuperTuxKart Networking - Looking for Testers

Nearly one year after the 0.9.3 release we are getting ready for the next release. And as many might know, we have actually been very busy working on the network implementation to allow online races. As expected, this has taken a lot of time, but we have finally reached a stage that we need more testing. For now we call this an alpha test, since there are still some known bugs and some polishing is required as well, but nothing that should affect the actual network race at this stage. De facto, we have been doing alpha tests with visitors on our IRC channel for some weeks now, so we actually do not expect any major bugs anymore.

In networked races the name of the player is shown on top of the karts
We are looking for people who can compile SuperTuxKart following our instructions themselves. You don't need to be able to program in C++ or anything. The main reason for asking you to compile yourself is that if a bug should occur, we can work with you to help us finding the bug. We are at the same time busy on working on a beta release (or even release candidate??), for which we will obviously provide binaries/installers for all common platforms. We actually don't expect this to be too far away ... fingers crossed.


SuperTuxKart Game Servers

We have over 20 servers running by volunteers (in Hongkong, Chicago, Netherlands, and some other locations) for the various game modes that we support, which includes normal race, time trial, battle mode, soccer and the new capture-the-flag and free-for-all modes.

Server Selection Screen
So, if you are able and willing to compile SuperTuxKart from git, follow the instructions but switch to the stable branch 'network' first. Also make sure to compile in release mode, debug mode is often too slow for the networking. Create an online account in STK, head for the online section and search for a server with a reasonable distance to you. If you connect to the server, the ping to that server will be shown - we would recommend to stay with servers that have a ping of under 100 ms. You can try servers with higher latency, and it should still work, but you might notice more often that karts stutter or are 'teleported' around.

 

Server Creation

Or create your own server and ask some friend to join, or head to our IRC channel #supertuxkart on the FreeNode network to ask for some people to join.

Server Setup Screen
We are also interested in getting some people to run some additional servers around the world, to offer a better ping for users. An STK server can even run on a Raspberry Pi 3. You can find instructions on network configuration in the file NETWORK.md (latest version here), but feel free to contact us if you have questions.

 

Testing

We would appreciate your feedback - especially how responsive and satisfying the race was, and what ping you had to the server you were using. Please provide feedback either in our forum, on our IRC channel, and file bug reports in our issue tracker.

Network Lobby
While this is happening, we will work on the important outstanding issues, and prepare a beta release which will of course include pre-compiled binaries and installer. Our main focus will be the interface, some physics issues, and other bug fixes. We are also interested to support playing with higher latency - but realistically there is only so much you can do if you will only know that a kart turned 600 ms after it happened (if both you and the other person have to wait 300 ms for a message to or from the server). In 600 ms a kart at high speed will have traveled over 13 meters. But we still have a few things to try out and improve on.