November 17, 2014

Awakening with a jolt; landing on a cushion

Zzz... *snort* *huff* oh, there you are! Sorry for the long hibernation in blog posts, but I became a bit too used to having GSoC students writing all of them. Bad excuse, and I will try to get back to a more regular schedule, so this post will try to catch up to what's happened the last couple months.

To begin with it's probably best to answer the question of when the next release is coming. 0.9 is still quite far off, so we decided to try making a 0.8.2 release as soon as possible, hopefully a beta/release candidate within the year. So you should have something to download in December; whether the final release will happen then or January is still left to circumstance (bugs, first and foremost). We still have about 100 open issues to either solve or postpone, so there's (more than) enough to do for everybody, and if you would like to try your hand at helping us we welcome you, especially if you have some programming or 3D modelling experience.

There have been many improvements to the new 3D engine we're using (less and less based on Irrlicht, and more and more custom), and while an image speaks a thousand words, a thousand images in the form of a video ought to be a whole essay. The following video is an engine demo made by our resident artist samuncle.

You can watch the video at and download the "kart" here.

Our artist samuncle has been hard at work indeed; check out the improved versions of Adiumy, Sara and Xue, in the tracks Cocoa Temple and Gran Paradiso Island.

Here's Sara on her snowmobile, showing off the extra pizazz the nitro effect has gotten recently, lighting up the new version of the STK Enterprise station. I wouldn't want to be right behind those thrusters; who knows what kind of strange radiation they're giving off! Apart from awesomeness. ;)

Oh, now we know. Thanks, Sara!

In miscellaneous changes, there's been way too many to list them all, but I'll mention a few very quickly.
The main configuration files now have their own sub-folder, so this means that in the future you can have several STK versions running simultaneously without getting issues where one version of the game overwrites another's configuration.
Some performance improvements have been made; for example we discovered a certain OpenAL call were slowing things down so we have minimized its usage and also moved sound to its own thread.
Physics has been improved again, specifically in landing after jumps. Now the karts are being cushioned from impact so there should be less issues with the chassis hitting the road, and karts adhere better to the road. (Maybe something for the ESA team?)
The following image is of the new screen for when you start STK 0.8.2 for the first time. You can now log in immediately to our stkaddons server which will enable you to vote on addons, see whether friends are online and view their achievements. Obviously the use of this feature will be expanded later when we have online multiplayer support and other things finalized.

Note that we collect anonymous statistics from your client if you choose to log in, such as what version of the game you are running, which OS you are using and graphics capabilities of your hardware. Your privacy is important to us, and we don't collect personally identifiable information (actually, we don't want it either). The code is open for all to see, and if you absolutely don't want to share info to us you can toggle it off in the options. However, the statistics could help us to see which platforms with what graphics capabilities are most used, and when problems arise we have some way to quantify how many might be affected. Also it gives us a feel of where we might be able to aim to when it comes to graphics performance vs fancy effects, though we will still try to make that customizable. On a final note, if you don't trust us on some level, I'd advise you to not install anything from us either... just sayin'. ;)

Hope you all are having fun with 0.8.1, and look forward to 0.8.2 which is going to be a quite major minor release... yes, 'tis confusing but ignorance can be bliss, and a stitch in time saves nine, and don't take any wooden nickels, and... later folks, some men in white coats are here to talk with me.

French translation avaliable here

STK team

November 1, 2014

Happy Halloween

Since an image is worth a thousand words, here's a quick Halloween picture made by samuncle :

This picture was rendered by the SuperTuxKart engine, so you can see how much progress has been done on the graphical engine side.

To all those curious to learn about when next version will be released : we expect a beta in the following weeks or months. There is still some work left, however, especially in porting tracks, so if any experienced modellers want to help we would be most grateful!

August 18, 2014

When Scripting Deserves to Fly

Hello everyone!

It's my very first blog post here, and I'm excited to bring to you the work I did as part of GSoC 2014!
Ever thought of an awesome and fun feature for a track you loved? Wanted the sheep in Green Valley to run away as you passed them by? Well, I've been working on a shiny new Scripting Engine for SuperTuxKart to allow all that and more. The best part is that scripting makes it unbelievably easy (and fun) to create good game loops! If you wish to know more, more details are available at

The first part of my project was to come up with a good language and an  intuitive and user-friendly scripting API. With this in mind, I chose AngelScript as the language, due to a variety of reasons, chief among them the fact that it had good synergy with our existing code. Most of my work went into refactoring existing code so as to expose that functionality to the API. Right now, most of the different track elements you see like animations, static objects have had various properties exposed to the API. I've also added several different ways of triggering scripts, from action-triggers (Think bubbles that pop and run a script when you enter it) to collisions (between karts, items and track-objects). In addition some miscellaneous classes have also been bound ( For example 3-D vectors ), to make life easier for anyone writing scripts.

The API is pretty comprehensive at this point (You can find the API documentation at, and I intend to broaden it further to allow more fun stuff to happen during races. I'm still hoping to do quite a bit of work post-GSoC on things like the weather, object behaviors and perhaps some unit testing as well.

I've added a tiny example (which is way more fun when you actually play it), for everyone to get a taste of what scripting will bring! Feel free to pull the ScriptEngine branch at for even more fun examples! You can find the scripts under stk-code/data/scripts.

An innocent looking barrel appears in Hacienda, let's check it out!

It's a trap!

The barrel has exploded into 2 parts, the rim and wonky-barrel

We'll be adding a video showcasing all the capabilities of the new engine once my work is merged, so stay tuned for more details!

August 13, 2014

SuperTuxKart Track Editor beta released!

Hi everyone!

I am happy to share the good news: the editor is ready for an open beta! Did you always want to create a track, but found Blender too complicated? Are you not afraid of trying a software which may crash? Are you ready to work hours on a track just to kill the program and lose everything? Are you good at finding bugs, reproducing and reporting them? Cool! I’m a pro marketing guy. This is our day!

After the last paragraph I am almost sure you can’t deny your desire to try the editor. How can you get it?

For this special event I made a binary version again. You can download it from here:

The zip contains an editor directory. Move it to your stk data directory, which contains Textures, Tracks, etc. All you have to do then is run the exe.

If you are a Linux user unfortunately you have to build the sources yourself – I doubt it will cause much pain anyway.
The repository is still the same:
You have to build irrlicht as well. Be careful and read the readme – most likely you have to modify an Irrlicht header.
Also, the SuperTuxKart wiki has a manual and a short tutorial for the editor:

If you have any question, idea, or just found a bug, you can find me here, on the forum, or on irc.
I hope you will enjoy your work ;)


August 2, 2014

Driving on walls? Yes please.

Hello everyone,

So this is my first blog post here, I should apologize for the long silence. For those who might have forgotten, my GSoC project was, simply put, allow karts (AI and player) to drive on walls and upside down. Now that the most of the AI is functionally capable of handling any kind of track that fancies your imagination, I think its now time to discuss some results.

The AI traversing a loop in Newton
Above you can see the AI skidding through a loop in a test track called Newton. (Ignore the flying kart in the middle, its some developer magic.) The AI still uses the old algorithm but now it does something extra. Imagine that the loop is made of a strip of yellow paper. Cut out the loop and flatten it on an imaginary table, and now try to navigate this flat loop using the old algorithm. Sounds easy right? That’s what the AI is doing, except its a little bit tricky to do in code ;) Once I got the steering right, the skidding “just worked”, which was nice.
Next we look at items. They are now auto-aligned depending on which section of the track they are placed at. These include bonus boxes, bananas, nitro etc.
An AI kart collecting a bonus box on a vertical section of the track
Powerups like bowling balls, cake, basketball and rubber band have also been fixed to work when being thrown from any orientation. Bowling balls will now follow the track instead of falling down. The cake and rubber band will now hit the target irrespective of what direction the opponent is going (assuming you are in range). The basketball has been fixed to bounce in the direction perpendicular to the track instead of the up-direction. It will now follow the track as you would expect.

The rescue animation was also required to be adjusted so that the kart is dropped in the correct place, with the correct orientation. If you are upside down when you drive off the track, then that is how you should be placed back. This turned out to be a bit tricky due to a bug between irrlicht and the physics engine but thanks to hiker’s expertise this was fixed. Along with this, the explosion animation is also fixed to be perpendicular to the track.

for the lulz
Most of the AI including items and other features had been previously designed with a horizontal track in mind. This lead to the AI being coupled with the coordinate system, ex. directly using the Y axis for many operations. Majority of the work has been done to decouple the coordinate system and AI.

All said and done, this project is not complete until we get some feedback from you, our loyal players. You may check out the source here , branch: walldriving. Build and run as usual and let us know what can be improved, and if you find a bug, even better :)