Wenzel's Blog » English http://mitsuba-renderer.org/~wenzel/blog Thu, 30 Jan 2014 23:17:42 +0000 en-US hourly 1 https://wordpress.org/?v=393 Still alive http://mitsuba-renderer.org/~wenzel/blog/2011/03/139/ http://mitsuba-renderer.org/~wenzel/blog/2011/03/139/#comments Thu, 24 Mar 2011 23:54:35 +0000 http://wazlaf.org/wordpress/?p=139

Is anybody there?

To say that it’s been pretty quiet on this blog would be a severe understatement, the latest post being from almost a year ago!  A small portion of the blame can be put on the software that used to run this blog, which made it extremely tedious to post an article containing many images.

Well, no more excuses — I switched to a much nicer software (WordPress) and managed to move all of the old articles. I also decided to write future posts in English, since all of my friends and family can all read that, which is less when I write in German.

]]> http://mitsuba-renderer.org/~wenzel/blog/2011/03/139/feed/ 0 Campus Tour http://mitsuba-renderer.org/~wenzel/blog/2007/08/campus-tour/ http://mitsuba-renderer.org/~wenzel/blog/2007/08/campus-tour/#comments Sat, 18 Aug 2007 14:52:12 +0000 http://wazlaf.org/wordpress/?p=106 I spent most of friday walking about on campus. It is strikingly beautiful. Most buildings are constructed in a style called collegiate gothic, which is a 19th century revival of gothic architectural designs. The nature around here is also very nice and there are lots of old trees and squirrels.


Some buildings on my way to the central campus

Since friday was move-in day, lots of tents and booths were set up everywhere. One consequence of having so many of these buildings on a slope is that you can enter them at ground level – and in order to leave at the other side, you actually need to go down four floors!


Willard Straight Hall (contains the student union)

The people here are very friendly and communicative. I had many conversations and took several guided tours. My head is close to bursting from all of the provided information… I also met two graduate students and we went shopping for the most essential things. Things are very expensive on-campus, but they become a bit cheaper in the malls and shops reachable by bus. Still, a box of cereal costs about $5, which is really expensive!


The Arts and Sciences Quad

There are lots of orientation sessions for the new students! Today, I had the international graduate student orientation. Tomorrow, there will be a normal graduate student orientation and on tuesday, there will be a special computer science orientation session.


War Memorial Building

Several small lakes and rivers run through the campus. If have time tomorow, I will go and try to explore some of those parts.


Beebee Lake and ‘The Slope’

So far, everything has far exceeded my expectations and I have had a wonderful time. I am really looking forward to my stay here and I am especially excited about the next few days.

]]> http://mitsuba-renderer.org/~wenzel/blog/2007/08/campus-tour/feed/ 4 I Arrived!! http://mitsuba-renderer.org/~wenzel/blog/2007/08/i-arrived/ http://mitsuba-renderer.org/~wenzel/blog/2007/08/i-arrived/#comments Sat, 18 Aug 2007 00:44:22 +0000 http://wazlaf.org/wordpress/?p=130 After an exhausting journey, I finally arrived at Cornell University. The atlantic ocean flight coordination system suffered a blackout, so my flight needed to be re-routed over skandinavia, iceland, greenland and canada (I could see icebergs from the plane)! In Manhattan, I went to the Cornell Club, which is a kind of fancy place for Cornell alumi. From there, I took the Campus-To-Campus bus line, which is a four hour drive to Ithaca.

I arrived at 1am and started searching for my dormitory, which is located downhill from the central campus. This was when I noticed just how steep those hills are. (The pictures were taken on the next day).

I had lots of trouble getting down these slopes with all of my baggage but eventually managed to get there. This is a picture of my dormitory:

I was able to check into my room even at this late time and fell asleep at once.

]]> http://mitsuba-renderer.org/~wenzel/blog/2007/08/i-arrived/feed/ 1 Getting ready to go… http://mitsuba-renderer.org/~wenzel/blog/2007/08/getting-ready-to-go/ http://mitsuba-renderer.org/~wenzel/blog/2007/08/getting-ready-to-go/#comments Wed, 15 Aug 2007 22:53:39 +0000 http://wazlaf.org/wordpress/?p=118 Tomorrow, I will be leaving for the USA. I am very excited about how things will turn out when I arrive there. I finally have my visa, the baggage is carefully tuned for the 23kg limit, and most things here in Karlsruhe are taken care of.

On Monday, my flat-mate and me painted my room in different shades of peach – she will move into the room while I am away. I think it looks very nice:



I will arrive in Ithaca, NY at 11pm and have no idea what I will do until the next morning.. During the next day, I will have to take an English test because my TOEFL score of 108 was one point below the required 109 of 120…. :(

]]> http://mitsuba-renderer.org/~wenzel/blog/2007/08/getting-ready-to-go/feed/ 0 The processor works http://mitsuba-renderer.org/~wenzel/blog/2007/06/the-processor-works/ http://mitsuba-renderer.org/~wenzel/blog/2007/06/the-processor-works/#comments Sat, 16 Jun 2007 20:08:00 +0000 http://wazlaf.org/wordpress/?p=97 About two weeks ago, I built the first hardware revision of the intersect processor. I was quite exited to start writing some programs using its acceleration features – only to find out that it encountered serious errors every couple of thousand operations. What happened is that it ‘choked’ from time to time and kept operations inside the intersection pipeline without ever finishing them.


A picture of the FPGA routing

This was awful since it wasn’t reproducible at all on computer simulations. And how do you debug a microchip? It’s like finding a needle in a haystack using a 50-foot pole and binoculars.
Today, I finally managed to pinpoint the error inside the caching subsystem, which comes as a great relief!

]]> http://mitsuba-renderer.org/~wenzel/blog/2007/06/the-processor-works/feed/ 2 About the name of this blog http://mitsuba-renderer.org/~wenzel/blog/2007/06/about-the-name-of-this-blog/ http://mitsuba-renderer.org/~wenzel/blog/2007/06/about-the-name-of-this-blog/#comments Sat, 16 Jun 2007 18:06:00 +0000 http://wazlaf.org/wordpress/?p=93 Ithaca is the name of a small city in the Finger Lakes region of New York state. It is the home of Cornell University and the North American seat of the 14th Dalai Lama :) (He is going to hold some lectures during August). I will study there during the academic year 2007/2008 to get a Master of Engineering in Computer Science.
The great thing about this one-year program is that it places almost no restrictions on the course selection, so I can attend all kinds of interesting computer graphics lectures without worrying too much about degree requirements. Cornell University is a member of the Ivy League and its faculty has done lots of important research in this field. I am thrilled to go there and it’s only two more months…

]]> http://mitsuba-renderer.org/~wenzel/blog/2007/06/about-the-name-of-this-blog/feed/ 0 The intersect core http://mitsuba-renderer.org/~wenzel/blog/2007/05/the-intersect-core/ http://mitsuba-renderer.org/~wenzel/blog/2007/05/the-intersect-core/#comments Sat, 26 May 2007 16:44:47 +0000 http://wazlaf.org/wordpress/?p=115 intersect is a project of mine on which I have been working for quite some time now. Recently, I managed to continue it as part of my Studienarbeit (kind of like a bachelor’s thesis in the German diploma system). I’ll blog about it from time to time for those who are interested in its progress. But first an introduction:

intersect is comprised of three parts: A special microprocessor, a linux kernel driver and a piece of software called beam. Together, they try to solve the problem which has become known as Global illumination (GI):

Global illumination algorithms used in 3D computer graphics are commonly used to add realistic lighting to 3D scenes. Images rendered using global illumination algorithms often appear more photorealistic than images rendered using only direct illumination algorithms. However, they are also much slower to generate and more computationally expensive. [Wikipedia]

Today, there are is an abundance of algorithms for computing Global illumination solutions and each one has some kind of severe drawback. One of the more robust algorithms is called bidirectional path tracing; its flaw is the excessive number of required ray-triangle intersection tests.
intersect uses bidirectional path tracing but takes a new approach: A custom graphics co-processor performs some of the calculations and makes use of the massive amount of parallelism. Up to 96 photons are simultaneously shot through the scene to speed up the calculations. The microprocessor is partly finished and for now, there is a software emulation to demonstrate its functionality. While it probably still has lots of bugs, it can already create some pretty pictures like this cornell box rendering:




Stay tuned..

]]> http://mitsuba-renderer.org/~wenzel/blog/2007/05/the-intersect-core/feed/ 0 Welcome http://mitsuba-renderer.org/~wenzel/blog/2007/05/welcome/ http://mitsuba-renderer.org/~wenzel/blog/2007/05/welcome/#comments Sat, 26 May 2007 16:29:59 +0000 http://wazlaf.org/wordpress/?p=95 Welcome to my blog! I have resisted starting one of these for a long time – now I have a good excuse. I’ve been admitted to Cornell University and will share the experiences of my year abroad starting in October.
Until then, I will use this spot to write about a university project called intersect and see what happens. See you around!

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