9 ms·
Quake on an oscilloscope
- dang 12y agoThis was posted earlier and set off the voting ring detector. I haven't looked closely, but that may have been a false positive. Since it's a good post and didn't get the attention it deserves, we won't treat this one as a duplicate.
- eps 12y agoIt was/is on top of proggit, so people must've just reposted it here en masse, driving the upvote count up quickly.
- dang 12y agoI think that explains it. Thanks!
- dalke 12y agoThere are currently 6 posts in the last 24 hours on this, of which 3 (including this one) point to variations of the same URL.
- dang 12y agoWe don't go by that so much as whether the post has had significant attention yet.
- johansch 12y agoI think your voting ring detection logic is perhaps overly simplistic, then. :/ (I tried to post it myself after seeing it on facebook in a swedish/scandinavian group.)
- tdicola 12y agoYour logic needs to be tweaked, I'm not a part of any voting ring or whatever.
- johansch 12y agoI think this post has just proven that any voting ring detector without NSA-level background detail on each voting individual is broken by design.
- dang 12y agoIt's a category error to expect perfection from a statistical system.
- lotsofmangos 12y agoSomeone should print that on the front of every textbook on economics.
- deleted 12y ago[deleted]
- TeMPOraL 12y agoGood to see that there are people in the loop constantly correcting false positives. As I said before, I like how HN changed recently. Thank you!
- frik 12y agoWow, great! I can only try to imagine how it would look on a oscilloscope with more MHz and a better soundcard.
- russnewcomer 12y agoAlways fascinated to see people use alternate input methods. I wonder if there is some possibility for steganographic applications with this? I.E., plug a soundcard into an oscilliscope, play a specially crafted .wav or equivalent file, and viola, secret message?
- amouat 12y agoSomething similar has been done on wavs e.g. when Aphex Twin hid his own face iniside the windowlicker track: http://www.bastwood.com/?page_id=10 http://www.bastwood.com/?page_id=10
- devindotcom 12y agoPlaid did this too on "In Threes." It's really fun to mess around with.
- kgabis 12y agoI once wrote a program doing something similar: https://github.com/kgabis/spectrum-printer https://github.com/kgabis/spectrum-printer
- kahacorp 12y agoHere's a music track which is its own music video when played on a 2D oscilloscope: https://www.youtube.com/watch?v=GvX5UWnUYTc https://www.youtube.com/watch?v=GvX5UWnUYTc
- ErikHuisman 12y agoclicking around after this video i came across this: https://www.youtube.com/watch?v=YqSvkNjWnnQ https://www.youtube.com/watch?v=YqSvkNjWnnQ wow that looks and sounds amazing.
- MrBuddyCasino 12y agoHypnotic. I wonder how the artist designed the visuals - is it only by math?
- bluedino 12y agoDidn't Woz have the original Apple computer outputting letters to an oscilloscope before he made the circuits to output to a television?
- ealexhudson 12y agoLots of older systems had vector rather than raster displays, from what I've heard of people who used them (too young myself) they were highly interactive - you could design movement and animation much more easily, and make the display very responsive. The major downside was not being able to do colour (easily), and not being able to cope with a lot of on-screen complexity (like the line count here not being much to shout about). Rasterised displays are a special case of vector, but with fixed bandwidth requirement.
- speeder 12y agoThere was a game console for vector games, named Vectrex. The games that ran on it were really interesting. Many modern games use the now high-resolution of raster displays to imitate Vectrex-style graphics. http://www.binaryzoo.com/games/echoesplus/echoesplus_4.png http://www.binaryzoo.com/games/echoesplus/echoesplus_4.png Note that the corners between straight lines are brighter, it is because on Vectrex the way to control line brightness was to draw it over itself, also line crossings were brighter too. Important to mention that many vector displays could NOT make curved lines though.
- tomswartz07 12y agoOne of my favorite vector games was Tempest. Vector graphics were some of my favorite, even growing up during the NES/Sega era.
- leoc 12y agoSeveral of the famous commercial arcade cabinets were vector too, including Asteroids, Battlezone and (as tomswartz07 mentioned) Tempest.
- deleted 12y ago[deleted]
- cubano 12y agoI'm old enough to remember when my college computer lab had an analog display for one of its systems...if I remember right, it was used for LaTeX applications and development, which during those days was still an interesting CS direction. I used to be mesmerized by it..everything looked so clean and modern, much better then the crappy 80x25 "workstation" displays of the VAX's and PDP-11's.
- Avitas 12y ago...a vector display.
- seanmcdirmid 12y agoThis doesn't make sense in my head: I don't think vector displays were ever used for type setting, but I would love to be proven wrong. Do you have anymore information?
- cubano 12y agoWell...maybe not LaTex, but some sort of mindblowing text to my CS101 mind. What I remembered was this device... https://en.wikipedia.org/wiki/Tektronix_4010 https://en.wikipedia.org/wiki/Tektronix_4010 The 4014 had a series of commands for drawing both text and graphics I was at the Florida Institute of Technology in 1985, and Lamport had just published the LaTex language and their was some interest in the department in getting a version of it running the the 4014... I think someone hacked a version of it...but my aging memory fails me.
- seanmcdirmid 12y agoVector displays don't usually handle text very well. They can draw perfect curves, but I don't think they could ever do the Bezier curves that fonts depend on. Anyways, what you are referring to is in between vector and rasterized displays. Still very interesting. I should ask my dad about this (he worked for Textronix in the 70s).
- rndn 12y agoAwesome idea and execution. I’m wondering whether it would work better with an edge detection algorithm instead of using the triangle edges.
- mistercow 12y agoSounds neat, but a bit complicated. You have to take those edges and turn them into an efficient set of paths for the oscilloscope to trace, and you have to do it very fast.
- deleted 12y ago[deleted]
- nitrogen 12y agoTreat the edges as nodes in a graph, then run a graph traversal algorithm like http://en.wikipedia.org/wiki/Eulerian_path#Hierholzer.27s_algorithm http://en.wikipedia.org/wiki/Eulerian_path#Hierholzer.27s_al... algorithm adding invisible edges to the next closest visible edge if you get stuck. One could get higher bandwidth by using the three color channels of an analog VGA output to control X, Y, and intensity.
- jokoon 12y agodefinitely the coolest cyberpunk thing ever I wonder if it could be emulated with a shader...
- zwegner 12y agoMaybe it's just me, but the audio output sounds really cool.
- peter303 12y agoThis was how we did computer graphics before there were affordable (less than $50K) frame buffers in 1980. In my 1975 MIT Digital Systems Lab my team constructed a hardware Game Of Life out of TTL gates. I designed the display as timed X-Y points on an oscilloscope. In those days a kilobyte of RAM still cost a hundred dollars, so the computer lab rationed the number of memory chips each team could use. I recall we stored the automata in a dual 64 x 64 bit frame buffer or two kilobytes overall. The first generation computer graphics languages were vector-oriented to support either oscilloscopes or pen-plotters. My first color frame buffer terminal was 512 x 512 x 8bits $30K AED in 1980. I think this costs than a dollar on a low-end cellphone now.
- VLM 12y agoAncient desktop is todays (or at least yesterdays) embedded. I guess this dates me but instead of taking the legacy Z80 embedded micro controller class a long time ago, I took the then new brand new 68hc11 class, although the Z80 guys got to use two DACs and a scope to display a cube on the scope as one of their labs. Now using a mhz class cpu to output a table at khz speeds isn't very impressive, so logically the next step in the lab was rotating the cube. I donno if they had to dream up their own trig or got a canned library. Maybe they canned the whole thing and just stored 30 or so frames of rotation data and switched which frame they displayed every tenth of a second or whatever. Donno didn't take the class but we got to see their work on lab day. I would imagine whatever took a "sheet of paper" sized development board with dedicated hardware DACs and eproms around 1990 could be done as a single chip solution today, assuming you can find a single chip solution that actually has two on board DACs. Or up the challenge by synthesizing PWM signals and low pass filtering them, essentially a class D amplifier controlled by software.
- kragen 12y agoThat sounds awesome. Surprisingly or not, PWM circuits (a counter and binary comparator) are more common than DACs on today's microcontrollers. I blew up some somewhat expensive tweeters finding out that just because you can't hear the 31.275kHz PWM carrier doesn't mean the amplifier isn't amplifying it.
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- lotsofmangos 12y agoThis would be a very cheap way of representing cyberspace in a b-movie. It already looks massively better than the Matrix's falling green thingies.
- mutagen 12y agoI wonder if the limit on lines was due to 20 kHz filters on the audio output. When the 24/96 audio sampling & perception discussion went by a few weeks ago I seem to recall some testing showing that even high sample rate sound hardware had low pass filters just above 20 kHz. This kind of issue should have been easy to spot in development and testing, though, so maybe just a limitation of the medium. I've got an old hobbyist oscilloscope, it was my former boss and mentor's first scope. I really should hack up something with it along with some of these low cost cpu boards.
- lotsofmangos 12y agoGiven that this is a realtime 3d space squished into the bandwidth of audio, could a variation be done with a worn kinect to feed into headphones an audio waveform version of current surroundings that is capable of being translated by the brain back into 3d. As that sounds like a possible hack for giving some form of vision to the blind.
- deeviant 12y agoI'm not so sure. The brain's ability to process and interpret visual information and form an intricate understanding of 3d space seems to me a "hard-wired" process. Sure, you could convert information encoding 3d space around a user and convey it to them in any number of methods, but that wouldn't leverage the brains very specialized mechanism for processing and interpreting visual information(which I rightly or wrongly conceptualize as a mix of hardware(some analogue of a video coprocessor for the brain) and software(the algorithms the brain uses to interpret the data).
- lotsofmangos 12y agoExamples such as Daniel Kish suggest otherwise - http://en.wikipedia.org/wiki/Daniel_Kish http://en.wikipedia.org/wiki/Daniel_Kish https://www.youtube.com/watch?v=ob-P2a6Mrjs https://www.youtube.com/watch?v=ob-P2a6Mrjs
- deeviant 12y agoThe first link is interesting, it does say the saw signs of activity in the same brain region of a blind echo-locating person as a sighted person who is activity looking at something, but it is hardly a smoking gun. Perhaps if you are defining "3d" information as something very primitive to the point of being "is there something directly in front of me", but nothing even as close as rich as even the quite crude 3d information being conveyed on the hacked oscilloscope outlined by the OP. I do see technology eventually giving blind people some sort of "sight" back, but not for quite some time, perhaps after there is some sort of workable neural interface that currently lives solely in sci-fi.
- mistercow 12y ago>This means the frequencies emitted are very high (5 samples per period is 19.2 kHz) and it seems the audio output is being low pass filtered resulting in silly wobbly lines. That effect actually looks amazing. I'd totally play a game with that aesthetic.
- fineIllregister 12y agoWould it be possible to recreate that effect on a raster display with a shader?
- pizzashark 12y agoIt might get a bit complicated but sure, there's no reason you couldn't.
- yoklov 12y agoPart of it would be done on a shader (mainly the visual portion, like the glowing and whatnot) but I think most of the effect would need to be done on the CPU. You might be able to make it work with clever usage of geometry or tesselation shaders though, and maybe also transform feedback. Honestly though, since the effect necessitates simple, low-poly geometry, doing the effect on the CPU shouldn't be too unreasonable, and would be where I would start. EDIT: Actually, now that I look closer, the one on the right here[0] could be done more reasonably in a shader, I was thinking closer to the one on the left (and how it actually looks in the video). [0]: hhttp://www.lofibucket.com/articles/img/speed_comparison.jpg http://www.lofibucket.com/articles/img/speed_comparison.jpg
- deleted 12y ago[deleted]
- k_sze 12y agoThat looks really trippy. I think it would actually be a cool rendering mode to have in FPS games in general, on computer screens, particularly the cyber-/techno-punk kinds.
- SCdF 12y agoTo bring this full circle, is anyone aware of a software oscilloscope for Windows / iOS that you could 'play' the wave file into to render his Quake demo via software?
- tenfingers 12y agoRegarding the sound card, from the description it looks like the "crappy" sound card also employs a high-pass filter. Is there a reason for it? What kind of circuit design in the DAC could cause low frequencies/significant distortion to require a high-pass at these frequency ranges? Genuine curiosity here.
- mmaldacker 12y agoIt's a low pass filter. And I'm assuming the low-pass is used in the DAC to cut off high frequencies it cannot handle.
- boomlinde 12y agoWhat frequency ranges do you mean? Digitally, you can feed the output very-close-to 0 Hz signals. Without a high-pass filter, this essentially means outputting direct current. A lot of audio gear don't take kindly to DC signals various reasons; things like amplifiers or headphones.
- cnvogel 12y agoMost PC sound cards employ so-called single-supply designs running their chips only between Ground and a single positive supply, e.g. 5V or 3.3V. So typically for a headphone output the amplifier will swing around 1.5 or 2.5V or so. To get rid of this offset, a capacitor is used. This capacitor, together with the headphones impedance, will function as a RC hipass.
- tenfingers 12y agoThanks for the explanation!
- Kiro 12y agoI don't know how oscilloscopes work. Is the sound in the game producing the actual image or is it generated from something else?
- random_ind_dude 12y agoAn oscilloscope is a cathode ray tube that has an electron beam that can be moved around by applying varying voltages to its inputs. In this case it works as an XY plotter, i.e., you specify the X co-ordinate by the value of the voltage on one input and the Y co-ordinate by the value of the voltage on the other input. You can display lines on the oscilloscope screen by giving a specially generated two channel audio as its input; one channel works as the X co-ordinate and the other one as the Y co-ordinate. The game (Darkplaces which is a source port of Quake) renders a scene that has the lines to be drawn (triangles, in fact) on screen. The output of the game, i.e., the lines to be drawn on screen are sent to an audio synthesizer process(PortAudio). This process uses a sound card to create the audio. The output of the sound card is connected to the inputs of the oscilloscope which draws the lines on its screen. So it's not the sound in the game that is producing the actual image. The output of the game is converted to an audio signal which when given as input to the oscilloscope creates the actual image.
- noonespecial 12y agoAt first, I thought this was just going to be another person discovering that analog TV sets were really just oscilloscopes with predetermined sync; and then setting up a sync for the scope to turn it into a little TV... How nice to be wrong! Hats off on this one. Nice hack indeed.
- FrojoS 12y agoFantastic example of how constraints form art.
- Nursie 12y agoThat's awesome. You truly can play quake anywhere. I always liked ttyquake, which replaced the renderer with an ascii-art output. Actually quite playable if you set your font size small enough and your xterm large enough...