BlaBlubbBlog

There is something really crazy I just found out about the login to Unix machines. And I have no clue why this 'feature' still exists besides pure nostalgia! What am I talking about? Well, you might be able to try that for yourself. Ctrl-Alt-Fn-yourself away from the splendor X is and login to your machine. Twice. The second time type your username in all-caps and be surprised. Here is what happens for me:

Welcome to jane!
I am running Linux 2.6.17-jane-2 on a i686.
You are on tty1.
How may I assist you?

jane login: steffen
Password:
Last login: Fri Nov 30 00:31:33 +0100 2007 on tty1.
No mail.
[steffen@jane ~]$ 

Okay, not quite that unusual. But now logging out and retrying it in all-caps:

Welcome to jane!
I am running Linux 2.6.17-jane-2 on a i686.
You are on tty1.
How may I assist you?

jane login: STEFFEN
PASSWORD:
LAST LOGIN: FRI NOV 30 00:32:28 +0100 2007 ON TTY1.
NO MAIL.
[STEFFEN@JANE ~]$ 

Und immer weiter geht's in den Ausbeuten. Heute auch wieder mit Schlachtschiff, allerdings ohne Drachen. Dafür ein Zwerg.

So, und noch eine kleine Ausbeute. Ich hole auf, der Stand ist dann Mitte September und fünf weitere Ausbeuten sind schon zusammengestellt. So Mitte nächster Woche könnte es dann wieder ganz aktuell sein (und dann kommen die Ausbeuten auch mit geringerer Frequenz, soviele Sachen sind dann nun auch nicht täglich auf CGTalk).

When the guys from Nightwish announced that they would cease working with Tarja Turunen last year (was it really last year?), the world was in shock. Well, not really. But Nightwish without Tarja? And what would she do? Well, this time I will only talk about the last question. She went off to do her own thing. Which in this case means asking for song-writers to send her material. And every good (and bad) album needs an associated tour of course. So when I read that she was playing in Berlin (interestingly I saw that in the discussion thread of the Nightwish concert which takes place next year in Berlin) I kind of felt obliged to go there too. After all, I do like her voice a lot.

Nonetheless I was quite sceptical. Not from the technical part, mind you. She can sing, no arguments here. But if the material is not good, the best voice cannot make it good. So I got one of the single versions of I walk alone and still wasn't convinced. It is a decent song, yes. But nothing too special. And the other song that is on the EP, Ciarán's Well, is rather mediocre, heavy, okay, but without soul.

Nach dem ruhigen Wochenende geht es gleich weiter mit der nächsten Ausbeute. Sind natürlich immer noch Altlasten und es wird auch noch eine Weile dauern, bis der aktuelle Stand erreicht ist. Aber dennoch gibt es selbstredend auch hier wieder sehr nette Sachen zu betrachten. Kaninchen vor!

Und weil es so schön ist, geht es munter weiter mit der CGTalk-Aufholaktion. Ich muß sagen, daß das mit den Skripten wesentlich angenehmer ist nun. Nicht mehr dieses nervige Rumklicken im Browser und Warten bis alle Seiten gerendert sind. Einfach, zack-zack, die neuen Sachen runterladen, schnell mit display ansehen und 'die Guten ins Töpfchen, die Schlechten ins Kröpfchen'.

I always wanted to look into visualizing all my fancy simulations. Never had the time, nor the motivation to do so. Until last night, at least with respect to the motivation, time I still don't have, but, oh well... I started to read up on how POV-Ray supports volumetric density media. Paul Bourke has a very nice article on that topic, which basically explains everything I needed. So the only thing that I need to do is to read all the particles from the simulation snapshot and put them on a grid. In a first approximation I used a cloud in cell (CIC) prescription, which means that a particle gives it's mass only to the cell it is located in, to calculate the density field. Once that density field is converted to a suitable binary file all that it is left to do is to write a really small POV-Ray scene. I basically used the MRI example from Paul's page to construct my scene and have a first working colour map (the tricky part).

And 'lo and behold, that is what I got (click for larger pop-up):



Not too bad. I need to play around with the colour map though to highlight the structure better. But already in this rough first attempt you can nicely see the filamentary and clumpy structure of the matter distribution. It is good to have a potent machine to do that on though. The density field is generated from 512³ particles (that is, 134 and a bit million). The raw particle data is already 4GB, the resulting density field (16bit dynamical range) 1GB since I used 800³ grid cells. The actually rendering was quite fast, 5 minutes on a normal P4 desktop machine.