Tuesday, April 23, 2013

Voxel Invaders on iOS!

Good news for iPhone or iPad owners: we have finally made it through the Apple store procedure: Voxel Invaders, our last video game is now available on iOS!

The game is now available on the main mobile plateforms and we are looking forward to compare sells on both :)

For techies, it is interesting to note that all versions of the game use the exact same C source code with the exception of thin wrappers for each plateforms. Even the online JavaScript version was generated from the pure C code using the powerful emscriptem!

Monday, September 24, 2012

Space Invader + Voxel Graphics = Voxel Invaders!

This week we (noctua software) released our new video game for android phone: Voxel Invaders.

This is the sequel of our previous game Retrocosmos and it follows the same principle of making a fun space invader game for touch screen devices. Only this time we used 3d voxels (the equivalent of pixels in 3d) for all the graphics! My brother Guillaume did a very good job coding the voxel graphic engine which delegates most of the computing on the graphic card allowing surprisingly fast rendering even on small devices.

The game is overall much more mature than the previous one, with more levels and more efforts put into graphics and gameplay. I also spent some nights creating retro sound effects with my good old Roland SH-101 analogic synthesizer and managed to compose 4 original soundtracks with my favorite tracker (OpenMPT). You can hear all of those in the demo video:

From a marketing point of view, we did two versions of the game: a free demo and a full paid version. We didn't put ads in the free version but simply limited the number of levels. Let's hope our users will find the game fun enough to buy the extra 20 levels!

Sunday, August 12, 2012

Alien Skull on Mars

I just spent some time looking at the amazing first full res pictures of mars taken by Curiosity, and I stumbled on this:
Yes, an alien grave with a skull! It's amazing how the human brain can see things it's looking for in random pictures :)

Friday, July 22, 2011

Stellarium in SOCIS 2011

Are you a student looking for an exciting summer job? Get paid this summer to work on Stellarium!

The Stellarium project was selected to be a mentoring organization for the ESA Summer of Code in Space 2011: a program funding european students for working on astronomy open source projects. Please review our ideas page and submit your application here.

The stipend consist in 4000 EUR (upon project completion), and is available for students from European universities (see this page for more details).

Hurry up! The application deadline is on July 27th at 11am UTC

Wednesday, June 15, 2011

Atmospheric refraction in Stellarium

The full moon eclipse coming "over bavaria" tonight (as said in the bavarian newpapers :) ) is a good occasion to show off the new atmospheric refraction code I finally had time to commit in stellarium (with important contributions from Georg Zotti).

The atmospheric refraction effect is a small deviation of light rays when they go through the atmosphere. It causes stars to appear higher in the sky than they are in reality, and this effect is mostly visible close to the horizon.

Luckily for the purpose of this post, today's moon eclipse is occuring very close to the horizon (in Munich) as you can see on this screenshot:

Moon eclipse simulated in Stellarium with atmosphere and refraction effect turned off (left) and on (right), at precisely the same time

What we can see in this image that:
  • the moon on the right appears higher in the sky as it would without atmosphere. This means that on the right side (and in reality) we are actually seeing light originally coming from below the ground! This also mean that the apparent rising time for stars, sun and other astronomical objects is shifted by about a minute with respect to the geometric position.
  • the moon on the right doesn't have the shape of a disk but rather of an oval. This is because close to the horizon the light is 'compressed' vertically because of refraction.
This refraction effect is much smaller further away from the horizon but still cannot be neglected when e.g. pointing a telescope. The blinking image below show what happens when atmosphere refraction is toggled on and off on a star field.
Click on the image to see a larger animated version

As you can imagine, this new feature was quite challenging to integrate cleanly in the code of Stellarium, and as far as I know, Stellarium is currently the only software able to simulate oval moons, and it does that in real time :)

To keep things short, the technical details will be the subject of another post.

Thursday, May 5, 2011

SVMT plugin for Stellarium

If you have been wondering what Diego and myself worked on for more than a year at ESO, here is a quick video answer realized by Diego:

And here is another video focusing on the GUI:

Seeing the videos, you may now think: it looks cool, but what the hell is that?

What is SVMT?
SVMT standing for "Survey Visualization and Monitoring Tool" is a plugin for Stellarium which allows astronomers at ESO to monitor the progression and completion of large sky surveys (realized by telescopes in Chile).

The main Stellarium screen (on the left) is used to display shapes in the sky representing the locations where pictures were taken by the telescopes. A special GUI allows to specify a set of contraints defining which data set we are interested in (by default all the data is displayed, yes that's millions of stuff!). For example, a typical query is "show me only the images taken by telescope X for survey Y between date d1 and d2". The results is then displayed graphically and some more contraints can be added in the GUI to continue refining the query.

There is also the possibility of comparing the result of several queries using a system of layers: one layer per query, and each layer has a different color. This allows to answer some questions such as "What is the percentage of completion of this survey in area?".

How does it works?
Technically, the whole GUI part (on the right) was coded in QML and is actually hosted on the server and downloaded by the client at startup. The queries themselves are computed on the server side and the result are returned as JSON files and displayed graphically on the sky and in the GUI.

One of the most challenging piece of code done for this project is a library for computing the intersection and union of spherical polygons. As far as I know Stellarium's code contains the only spherical geometry library capable of managing spherical polygons which are non-convex (i.e. with holes or strange shapes) and potentially larger than 180° (i.e. larger than a half sphere). It is on my TODO list to write another post about that.

What's next?
Now that me and Diego left ESO, there is currently no maintainer for SVMT. However, the code is entirely open source (GPL license) and its design was done keeping in mind that it should be re-used for other data sets. Please contact me if you have any interest of re-using the code for other purpose.

For more info
Try a demo version (with public data sets only)
See the project Launchpad page.
Have a look at the Developers Documentation

Looking for a job

After spending some months playing with small personal projects, it's now time for me to look for a proper job! For those interested, I just updated my CV [html|pdf].

Note that I am also available for specific consulting regarding Stellarium or other programming tasks!