pixel jet stream

2011-09-09T08:42:00.014+02:00

mini lua primer

estrela as shader editor

2011-01-01T14:28:00.005+01:00

Recently doing more work with Lua and Cg/GLSL again, hence added a couple features to estrela editor.

Lua wise I had added some experimental type-guessing mostly meant to aid auto-completion for luxinia classes. Also the lua-apis that get loaded can now be specified by interpreter, so that no luxinia functions get suggested when you are using a "normal" lua interpreter. Getting useful auto-completion and api help is still a big task so. Especially getting user created functions/classes in somehow would be great. Maybe a static tool that generates files from a lua project or so.

Most problems with "dynamic" text analysis was that when the user edits old stuff, you have to also somehow check whether keywords were changed, added, removed... hence I kinda avoid that complexity yet. I'd rather prefer a static solution that the user triggers, that way it's hopefully simpler and more robust.

Another focus lately was the Cg tool. I've added support for nvShaderPerf and an ARB/NV program beautifier (indenting branches/flow, and inserting comments as to which constants map to what variable). That makes it a bit easier to see what stuff triggers branching and so on.
I've also added automatic setting of GLSL input flag for cgc and some automatic defines such as "_VERTEX_"... so that one can use #ifdef _VERTEX_ and still have all GLSL shader code in one file. A GLSL spec and api description is now also part of estrela. I took the nice opengl 4.1 quick reference card as base. So much for now.

Still haven't found time to push the open-sourcing of luxinia further and add GLSL shader management (but will require ARB_separate_shader) to it for PhD work. But anyway new year now ;)

3point shader

2010-07-05T11:04:00.004+02:00

So long no updates, well mostly I am still working on PhD stuff. Finally the publication on smartvisibility rendering techniques for medical datasets is out

http://www.springerlink.com/content/94n1840v2602646w

And I am mostly working on a CUDA port of vessel histogramm analysis and a bigger system on coronary heart vessel exploration.

Furthermore, the 3point shader http://www.3pointstudios.com/3pointshader_about.shtml is also released (both commercial and non-commercial free edition). The free edition uses the same plugin and shader, but doesn't have the convenient and time-saving ui, as well as no sample files... that said if you want to play with it, you can do so for free.

A major contribution in this work is the fix of 3dsmax's broken tangentspace normalmap display in the realtime viewport. They don't send the same tangent space as they do when the scanline baker generates the normalmap. Autodesk was made aware of this problem. The cool thing is that as it simply is a viewport fix, one can get great quality improvement out of all standard bakes. And people no longer have to waste additional geometry to fix the "smoothing" issues the broken viewport had.

Thing is that many game companies have "taken" the broken viewport for the "correct" tangentspace, which it simply isn't, as Autodesk has several inconsistencies within max SDK for exposing the tangentspace. If you are interested in the fix or how to use it in game engines, you can contact 3pointstudios about it.

Another addition to the plugin/shader is mirroring support for object-space normalmaps. I have experimented with that for quite a bit, as well as transforming object-space to tangentspace in offline tools to allow exchanging the baker. Anyway the plugin generates per-vertex reflection vectors for the os-normalmaps, as long as you offset mirrored uv parts by a multiple of 1 (which you would anyway to prevent baking overlaps).

function call highlighting

2009-11-14T16:12:00.003+01:00

I am quite a visual assist addict, and miss some of its features in other IDEs. For luxinia's Lua and Cg use, I tweak the estrela editor to my own needs. wxWidgets's scintilla version, doesn't allow you to use the style-bits as flexible as I'd love to do. As a result the lexer overwrites the manual changes one does. But with the indicators at least, you can make sure they aren't modified. So the latest addition is function-call highlighting, something I really like in VA.

As you might see on the text I am also working on a Lua binding for OpenCL. Whilst I've used manual bindings before, this time I used swig. It needed a few "dirty" hacks and a swigutility library, but now it more or less works fine. Binding, sources and samples will come with a future luxinia release.

the realtime GI course

2009-10-14T17:11:00.002+02:00

Thorsten just told me about the realtime GI course (Siggraph 2009) being available online
http://www.cs.ucl.ac.uk/staff/j.kautz/RTGICourse/

He also hinted me towards the GI compendium
http://www.cs.kuleuven.be/~phil/GI/

the virtual endoscopy

2009-09-18T13:23:00.009+02:00

Here you can see the lung. For a upcoming presentation, I've been messing with some settings with the endoscopy system I've developed a year ago with focus on nasal sinuses, however it works for other hollow organs just fine. My supervisor on this project (diploma thesis) had made contacts with the university clinic in Leipzig and together with a leading ENT-surgeon, the usability of the system was tweaked. At the end it was used in larger clinical study at two locations with some 100+ patients (who prefered virtual pictures over video hehe). Texturing is tri-planar and several post steps are needed to smooth normals and so on (inter-leaved sampling, hitpoint refinement....).
More details about implementation can be found in one of the publications around this project:
SinusEndoscopy-IEEE Vis 2008 Paper, Slides

Main focus was a surface depiction that is similar to what the surgeons are used too (but not too real, to prevent false impression of too much data security, CT cannot show tissue diseases). The effect is similar to the Cascades-Nvidia demo.

And some videos:
IEEE Vis 2008 Video
Colonoscopy
Neck endoscopy

the simple cuda test

2009-08-28T18:45:00.006+02:00

The refactoring and rewriting of luxinia's internals goes on, prior open sourcing the full project (cleaning up code and trying to apply some of what was learned). On the side to have some fun, further dx10 features (ogl equivalents) are added. So more of GL's bufferobjects features are made accessible on the Lua side.
A result was a small sample of coding up a lua extension dll, which runs a cuda kernel on a vertexbuffer. I never played with Cuda before, and kinda missed the built-in vector types of Cg, ie that float3*flaot must be done via operator overloading in cuda... means the compiler has to do vectorizing himself (but he can, compared to Cg). I've modified the simpleGL nvidia sample to make use of custom vertex color attribute. It's really nice that cuda supports the datatypes, transform feedback wouldnt allow you to store back to smaller datatypes.
Next comes up adding transform feedback, so that you can specify output streams in a shaderpass and streamobject will be a resource like a texture, assignable to material instances. First will only do for nvidia profiles. I still use Cg runtime quite a bit, so doing it for their GLSL profiles is a bit ugly at the moment. Not sure yet if I stick to Cg runtime, or just use it for compilation and do parameter and program creation all myself, would be a bit "what you want is what you get", but also more work now.

the new siggraph stuff

2009-08-11T13:12:00.003+02:00

just looking at the various stuff coming from siggraph (check Atom blog for some onsite info)

light propagation (first bounce GI) in CryEngine3
http://www.crytek.com/technology/presentations/

And more links from siggraph at beyond3d and another interesting slides by Epic's Tim Sweeney

on a side-note, I did not go for the GC in C, but use a more simple refcounter similar to boost's shared/weak pointers with a dedicated allocator.

the idtech5 virtual texturing

2009-08-08T09:24:00.002+02:00

just saw this http://s09.idav.ucdavis.edu/talks/05-JP_id_Tech_5_Challenges.pdf on gamedev, some slides about the virtual texturing in idtech5 (Rage).
Other recent things I stumbled upon were of course the OpenGL 3.2 specs (yeah they finally get some momentum and turned "compatibility" into a profile, not that ugly giant extension). I am currently looking into C hashing libs and a garbagecollector for C. Reason is I want to better split the luxinia GC system from Lua, so that we can move on to using SWIG, ie providing a proper C api (and not just the Lua binding) but keep the reference system working. Smart pointers are not an option as it's too much of an issue to prevent cycles and in general I want to keep the core engine Ansi C.

the good read

2009-07-16T13:13:00.003+02:00

Bruno, a friend of mine, gave me a link to a very nice essay today
http://www.longnow.org/views/essays/articles/ArtFeynman.php

It's about the early days of "Thinking Machines", a company that built parallel computers in the early 80s, and how Richard Feynman helped them in an almost fatherly role.

And stumbled upon anther creative mind today, Michel Gagne. Very cool illustrations and the latest game based on his universe looks fantastic.

the 3dsmax sdk frustration

2009-07-11T14:49:00.005+02:00

3dsmax sdk gives me so much love... not. Today found out (the hard way) that their BitArray.EnumSet function is broken in 64 bit...

on a sidenote the SDK states if you want something you draw in viewport to have a fixed nonscaling size, to use

vpt->GetVPWorldWidth(wpt)/360.0f;

however this isnt correct, you want to use

aspect = ((float)gw->getWinSizeX()/(float)gw->getWinSizeY());
aspect = max(aspect,1.0f);

(vpt->GetVPWorldWidth(wpt)*aspect)/(float)gw->getWinSizeX();

the jump page

2009-06-30T13:33:00.016+02:00

I will update this post, with useful links.

best "state of the art" stuff, mostly by top companies, latest tech (starcraft2, crysis..)
SIGGraph course on real-time rendering
(2006) http://developer.amd.com/media/gpu_assets/Course_26_SIGGRAPH_2006.pdf
(2007) http://ati.amd.com/developer/SIGGRAPH07/Course28-Advanced_Real-Time_Rendering_in_3D_Graphics_and_Games_SIGGRAPH07.pdf
(2008) http://ati.amd.com/developer/SIGGRAPH08/Siggraph2008-Advances_in_Real-Time_Rendering_Course.pdf
http://www.codersnotes.com/notes/papers-please (overview on classic graphics papers)
(2009) more to come: http://www.bungie.net/News/content.aspx?type=topnews&link=Siggraph_09

Siggraph 2008 GI course: http://www.graphics.cornell.edu/~jaroslav/papers/2008-irradiance_caching_class/index.htm

and because I mostly just grab links from these:
company publication sites
(pixar) http://graphics.pixar.com/research/ (the mecca)
(guerilla) http://www.guerrilla-games.com/publications/dr_kz2_rsx_dev07.pdf (killzone 2 tech overview)
(valve) http://www.valvesoftware.com/publications.html (valve has lots of papers on their tech, really good stuff)
(bungie) http://www.bungie.net/Inside/publications.aspx (also spilled the important beans similar to valve)
(insomniac) http://www.insomniacgames.com/tech/techpage.php (more ps3/code oriented)
(epic) http://unrealtechnology.com/whats-new.php?ref=downloads
(nvidia) http://developer.nvidia.com/page/documentation.html
(ati) http://ati.amd.com/developer/techreports.html
(crytek) http://www.crytek.com/technology/presentations/

hair
http://graphics.stanford.edu/papers/hair/hair-sg03final.pdf
http://ati.amd.com/developer/gdc/scheuermann_hairrendering.pdf (real-time variant)

shading
http://www.valvesoftware.com/publications/2006/SIGGRAPH06_Course_ShadingInValvesSourceEngine.pdf
http://www.bungie.net/images/Inside/publications/presentations/lighting_material.zip
http://web4.cs.ucl.ac.uk/staff/t.weyrich/projects/phd/weyrich-2006-phd-lowres.pdf

compression
http://developer.nvidia.com/object/real-time-normal-map-dxt-compression.html

meshing / deformation
http://www2.in.tu-clausthal.de/~hormann/parameterization/index.html
http://graphics.uni-bielefeld.de/publications/papers/
http://www.cs.nyu.edu/~sorkine/

filter/image
http://people.csail.mit.edu/sparis/bf_course/
http://web4.cs.ucl.ac.uk/staff/t.weyrich/projects/xlrcam/kim09xlrcam-lowres.pdf

architecture
http://beautifulpixels.blogspot.com/2008/08/multi-platform-multi-core-architecture.html
nice post by a gamebryo dev on the different architectures.
http://www.crytek.com/fileadmin/user_upload/inside/presentations/2009/A_bit_more_deferred_-_CryEngine3.ppt

raytracing
http://ompf.org/forum/viewtopic.php?f=3&t=9

mostly code related, sometimes however hints at what tech is to come in future
individuals / blogs
timothy farrar (human head): http://farrarfocus.blogspot.com/ http://www.farrarfocus.com/atom/
ignacio castano (nvidia): http://castano.ludicon.com/blog/
wolfgang engel (former rockstar): http://diaryofagraphicsprogrammer.blogspot.com/
tom forsyth (former radgametools, now intel): http://home.comcast.net/~tom_forsyth/blog.wiki.html
Iñigo Quílez (demoscene): http://iquilezles.org/www/
Kun Zhou (researcher): http://www.kunzhou.net
Rui Wang (researcher): http://www.cs.umass.edu/~ruiwang/#publications
Carsten Dachsbacher (researcher): http://www.vis.uni-stuttgart.de/~dachsbcn/publications.html
Szirmay-Kalos László (researcher): http://www.iit.bme.hu/~szirmay/puba.html
http://erdani.org/publications/
Marc Stamminger (researcher): http://www9.informatik.uni-erlangen.de/people/publishedby/marc/stamminger/
computer graphics at williams college: http://graphics.cs.williams.edu/papers/
Jiaping Wang(researcher) http://www.lightthoughts.com/jpwang/
icare3d (researcher): http://www.icare3d.org/blog_techno/
Jaroslav Krivanek (researcher) http://www.graphics.cornell.edu/~jaroslav/

the trine time

2009-06-28T14:04:00.003+02:00

I've recently stumbled upon a very nice game to appear soon Trine. There is a demo for the PC version. It has gorgeous graphics and cool gameplay. Good old 2d gameplay but with recent looks. It's a bit like Lost Vikings with different characters having different abilities. Very refreshing from the "next-gen shooters / 3rd person action". It also shows that narrating a story doesnt have to "cost" a lot. They use moving images with parallax effects for narration (bit like Max Payne, though different style) and have very good voice acting.

Speaking of games, I've grabbed the Armed Assault II demo, lots of gigs. And was rather disappointed. While it's essentially the same gameplay as in Operation Flashpoint I, it has insane hardware requirements, and given that, it doesnt feel that much "bigger" than the original OFP. I wonder where all the development has gone into. Characters surely look nicer, and so does the vegetation. But the classic issues of AI problems, and "visibility" problems with lying in grass, that fades out with distance, still remain. Developers should have foremost focussed on that. In the meantime I can recommend Project Reality for BF2. It has a similar realistic/tactic approach to gameplay as OFP, but hosted in the nicer BF2 engine.

At the moment I mostly play GTR Evolution using my forcefeedback wheel + pedals, it's a blast. Graphics of environment are clearly inferior to the more arcade games (GRID), but the physics/handling and sounds are awesome. Oh and the people who drive the Nordschleife for real... insane...

the drawing past

2009-06-14T18:49:00.000+02:00

As in school or army I liked to doodle a bit during lectures in university. Now you will notice what I draw is in very strong contrast with the military models and animations I did before ;)

Due to the difficulty and heavy training needed I mostly avoid drawing humans, but from time to time I try. I havent done much drawing or "art" related work recently, so work presented here is several years old. I've finished school in 2001, army in 2002 and diploma thesis (studies) in 2008. But I try to invest some more time into it again. There is a nice program called artrage2 for drawing on the computer.

the lowpoly past - part II - freelancing

2009-06-14T17:17:00.000+02:00

just coming home from a gorgeous once in a lifetime lovely fairytale wedding of my cousin. First some more background info.

During studies I did a little bit of freelancing for game art. Thanks to a colleague from the first mod I worked on (TerrorQuake2), I made contact with Lemsko, a German 3d artist and virtual aviation enthusiast. With his support I did work for IEN on warbirds2 and their tank game armored assault... yeah back then I was into military models quite a bit.

For a fantasy competitive jump'n run quake mod following animations were created. I've also done a bit of character work for that project, which died soon.

The earlier military model work lead thru freelance work for esimgames.

As my studies required lots of time, I only did very little freelance work basically to keep the 3dsmax license floating ;)

the lowpoly past - part I - quake days

2009-06-11T13:53:00.000+02:00

From early on I enjoyed watching movies a lot, especially the technical effects have always fascinated me. Seeing Star Wars for the first time, I was amazed at how convincing the scenery was set; the world seemed so real. After watching the Terminator, Abyss and other early CGI movies, this new technique of special effects got my attention.Finally, Jurassic Park in 1993, assured me that I want to do that in future, I want to create my own dinosaurs and bring my own worlds to life... This is why I got into 3D-modelling and animation.

CGI knows almost no limits, the creative mind can fulfill its dreams to all extents. This fascinated me, and still does. I enjoyed playing with LEGO's a lot, and once I moved from the floor to a computer desk, it was finally possible to bring things to life on the screen. With a 3D studio r2 dos student version I made my first steps in 3d. Having no internet and no tutorials I had to bite thru the complexity of this program myself. Once I got the hang of it, I wanted to do big stuff immediately, but the projects I set for myself were always too big, or too time consuming; I preferred playing games a lot more. Another reason was that I didn't really want to model all the things necessary, I wanted to animate it... so no project was finished, but I gained some experience on timing, camera movement, etc...

Later on I united my love for 3d with my love for computer games. After getting into the internet I searched for better software, tutorials and of course games. The Quake2 modification community caught my attention. There I found other young developers who create their own games, and of course need 3d art aswell, models of weapons, characters... My first job was being a modeller for Terror Quake 2 around late 1998. After the team was restructured I also took over the job as animator. Since this team, which later changed name to TeamHavoc, absorbed me I have been working on mods for quite some time. I was lead animator for a Quake3 mod, called Urban Terror. Thru this team's skill and good connections to id software, I managed to get a license of 3dsmax at quakecon 2000, thanks again to my teammates from Silicon Ice Development, to id software and to discreet for giving away some copies to young developers.

Here is some work for urbanterror (mostly animations, but also some weapon models):

With starting my studies of "computational visualistics" at the Otto-von-Guericke University of Magdeburg in 2002 I left the development team of urbanterror before beta3 release and got more into coding myself.