Thursday September 28, 2006 Seapegasus Blog
Thursday September 28, 2006 You like RPGs? Then get Progress Quest! This game is worth booting Windows.
Really!
Trust me. :-D
Posted by seapegasus ( Sep 28 2006, 09:27:55 PM CEST ) Permalink
Friday September 22, 2006 Polygons! They Are Everywhere!
Woah. Recently, when I look at buildings and streets, all I see is vectors, polygons and vertices. I had taken the first week of September off and, among other things, had a closer look at some 3D (game) engines, and 3D mesh editors. Mesh-editors are those tools to create 3D objects that you use in the 3D engine later. The engine is the piece of software that renders the 3D objects live and - if it has a game physics component with gravity and collision detection included - lets you walk through the 3D scene.
I had tried to write my own 3D engine in Cocoa once, not because I thought it would be better (in fact my demos were quite inefficient), but just to understand how basic 3D rendering algorithms worked. Pretty interesting stuff though!
- First, there's the Bresenham algorithm for drawing lines as approximations (stair-stepping pixels). It can be adapted to draw filled polygons too.
- Next you need to implement the projection formula that renders a 3D object in memory as a 2D image on the screen.
- When you got that part set up, you need to deal with transformation formulas for rotating, scaling and translating (moving) wireframe coordinates.
- Then when drawing an object, there's a formula to identify and cull backfacing polygons -- since your program will stubbornly render all 6 sides of a cube simultanously unless you tell it not to.
- The next issue is similar: As soon as you have more than one object in the scene, you also need to deal with overlapping polygons, and your programm can't decide the criteria on its own which of the overlapping polygons to draw and which not -- so you need algorithms for hidden surface removal. Actually, you can choose between two of them:
- The painter's algorithm simply sorts all polygons in the scene by depth, and draws all polygons from back to front, so that front objects are drawn over the background as it should be. A lot of redundant drawing, but works.
- A more efficient but complexer solution is the z-buffer algorithm: The z-buffer is named after the z-coordinate (depth). The buffer itself is implemented as a 2D array that stores each pixel's depth value -- because depth is the information that is lost when projecting a 3D coordinate to 2D coordininates on the screen. For every pixel P you draw to the 2D framebuffer, you check the z-buffer at the same coordinate: If there already is a lower (closer) depth value recorded, you don't draw P, since it is be behind another existing pixel. If there is no recorded pixel depth yet, or the recorded depth is further away than P's, you draw P to the 2D framebuffer, and record P's depth for this coordinate in the z-buffer -- etc.
Well, my own "3D engine" never reached any degree of usefulness beyond a study project. That's the reason why I eventually started looking into existing 3D engines and mesh editors for MacOS:
- The first mesh editor I tried was ArtOfIllusion. It is free, platform-independent, very easy to learn, and it exports 3D objects in Wavefront's widely used .obj and .mtl format.
- I also tried the infamous Blender. If you ever used it, you will certainly recall your first impression. Are they serious about the UI?! Yes! Blender is to mesh editing what vi is to text editing. Not exactly intuitive, but as soon as you learn you are meant to use all three mouse buttons in sync with keyboard keys, it slowly starts to make sense... Luckily there is a Blender tutorial. Mac users note that it's possible to use Blender with Apple's MightyMouse, but it's not optimal.
- Last but not least: The 3D engine I looked at is Irrlicht, a free platform-independent c++ library. I wrote down the steps my brother showed me how to compile the library and set up a Carbon project for MacOS X: Irrlicht in Apple XCode. There is still one open question at the end (about textures), but it should be enough to get you set up and running.
Wednesday September 20, 2006 More NetBeans Events in Germany
(This is an announcement for a Java and OpenSolaris event in Germany).
Hab gerade von Roman gehoert, naechste Woche 26-27. September 2007 ist die Source Talk Conference in Göttingen im Mathematisches Institut der Georg-August-Universität.
Es wird Workshops und Tutorials geben ueber OpenSolaris und Java (Tools, Modular Swing Development, Java Performance Tuning, Netbeans + Java EE 5, Workshop EJB + JMS, Web Framework Plugins fuer Netbeans)...!
Zielgruppe sind Software-Developer, Administratoren und IT-Architekten. Es sprechen Leute von Universitaeten und aus der Industrie (also nicht nur Sun).
Die Vortraege scheinen groesstenteils auf Deutsch zu sein, ein paar wenige (wie die von Roman und Geertjan!) sind wohl auf Englisch.
Posted by seapegasus ( Sep 20 2006, 12:17:35 PM CEST ) Permalink
Monday September 18, 2006 Okay, registration for the first meeting of the NetBeans User Group Munich is ready and open now. Don't forget that you still can contact Roman if you want to talk in a guest speaker slot. This is the first meeting in Munich, and we hope there will be more, so if you don't have time in October, you can join (and give a talk) later.
Hier könnt Ihr Euch für das erste Treffen der NetBeans User Group München anmelden. Wer einen Gastvortrag halten möchte, kann immer noch Roman kontaktieren und sich mit ihm absprechen. Wenn Ihr im Oktober beim ersten Treffen keine Zeit habt, einen Vortrag vorzubereiten, könnt Ihr das auch bei einem der (hoffentlich!) folgenden Treffen tun. Die erste Vortragsrunde ist hauptsächlich auf Englisch, aber je nach Angebot der Gastsprecher werden in Zukunft auch deutschsprachige Vorträge vorkommen.
PS: Speaking of NetBeans Days and similar events, I also updated the worldtour dates that had not yet been confirmed, and also the list of keynote speakers.
PPS: Did I mention there will be a NetBeans Day in Paris on March 19, 2007? More on that soon...
Posted by seapegasus ( Sep 18 2006, 06:49:17 PM CEST ) Permalink Comments [1]New stuff I just discovered on the NetBeans Update Center: JavaScript and CSS Editor, Run Terminal, iSpell checker + English dictionary. Spiffy.
The spell checker does not have any UI, it just makes wiggly lines under your javadoc comments. That's useful, I would just have expected a suggestions window somewhere. (If I am missing anything please tell me!)
The spell checker does have a prominent entry under Tools>Options though, in case you need to change the language to British for example. Unfortunately, it is not meant for HTML or other code yet as I was hoping. Hmmm. This actually is where I'd have to say "I'll just go implement that!" Unfortunately I'm a lousy programmer. =-) Is it difficult to add support for HTML, does anybody know? (I'm gonna ask jlahoda too.)
PS: More about spellchecking html from nobody else but Geertjan himself.
Posted by seapegasus ( Sep 18 2006, 03:42:24 PM CEST ) Permalink Comments [2]
Thursday September 14, 2006 Who says there is no NetBeans Day in Germany this year? Come to the NUG! As Roumen already mentioned (in English), there will be a NetBeans User group meeting in Munich in October. The agenda is almost the same as on any other NetBeans day, so this is a great opportunity. Here's the translation of the invitation.
NUG: Wir laden herzlich ein zum ersten Treffen der NetBeans User Group in München!
Wann: Dienstag, 17. Oktober 2006, von 10:00 - 16:00 Uhr
Wo: Sun Microsystems, Inc.
Sonnenallee 1
Kirchheim-Heimstetten 85551 DE
Phone x62558/+49-89-46008 2558
Fax +49-89-46008-2572
Programm
- Begruessungsrede: NetBeans Zunkunftsplaene und Vision
- Java EE 5 - Did you get your tools with that?
- Unpack your favorite feature
- Mittagspause (30 min)
- NetBeans Extreme - Matisse, Profiling, Rich Clients and More! (*)
- Gastvortrag
- Diskussionsrunde und Empfang
If you want to be a guest speaker, either for this event or for one of the next meetings, post your ideas in the netbeans-forum.de, or send them directly to Roumen.
PS: The Czech JUG has had its first meeting yesterday. Of course, Prague always has to "one up" Munich. :-D
PPS: I was on vacation last week and I still have a couple interesting blog unposted drafts lying around... *sigh* So stay tuned while I catch up!
PPPS: (*) OK, scratch that -- the agenda will change again to look more like a netbeans day, I'll keep you posted.
Posted by seapegasus ( Sep 14 2006, 12:42:01 PM CEST ) Permalink
