File this one under "Cool but useless"
I stumbled across js1k.com yesterday and was quite amused by the concept: Use 1024 bytes or less of javascript in a minimalistic shell page to create a cool demo. The contest is over now, and browsing through the winning entries is surprising and somewhat awe inspiring. They managed to get a full Chess AI and graphics in 1k of javascript?!? Awesome! It also got me thinking: None of the demos used WebGL (primarily for compatibility reasons. The rules state that demos must work in Safari, Chrome, Firefox, and Opera), but were the standard further along, how much COULD you do with a 1k WebGL app? I decided to find out!
Wednesday, September 29, 2010
Friday, September 24, 2010
Raytracing in Javascript
So I've been pretty quiet lately, but not for lack of activity on my part. I'm in one of those funny stages right now where I've got about a thousand ideas I want to try and things I want to learn and not enough time to pull any of them off properly. So I experiment, whip up several dozen cool little proof-of-concept programs, and move on to the next idea. This kind of "brain dump into code" mode is pretty fun, but has the severe downside that none of your projects reach a point where their worth actually showing to anyone else. Recognizing that my blog has been sorely neglected as of late I determined that I would bring at least ONE of my playthings to a semi-showable state and post it, and it so happens that my raytracer was the closest to being presentable. :)
Yes, it's a browser demo (but not a WebGL one, sorry!) It's a Monte Carlo tracer, which means that the image starts out really ugly and gets better as more passes are applied. (Let it sit longer and it becomes prettier.) The image above is the result of letting it sit for 400 passes, and even then you can see a fair bit of noise. It's a very slow way of going about it, but it can produce spectacular results under the right conditions (and, you know, when you're not relying on Javascript to do it...)
Okay, so admittedly this is probably the least impressive demo I've done so far. It's your standard old boring Cornell box, and not even a really cool one at that because it lacks a refractive (glass) sphere. (More on that in a bit). There's a whole bunch of things "wrong" with it, and I may be tempted to come back and update it at some point, but the point of the thing was that I wanted to learn more about raytracing, and this little guy has served that purpose admirably.
A few fun "techy" notes: This started life as a Python port of smallpt, which I eventually gave up on when I realized that the GIL makes threading for this type of thing pretty useless. So I ported my port to Javascript (wait, aren't we moving backwards here?) mostly so I could use Web Workers, but it has a nice side effect of letting me demo it online. :)
The demo uses 4 web workers (though it's super easy to scale to more or less), each of which renders their own jittered version of the full scene. All passes are then send back to the main thread and composited into the final image. I'm actually passing the image data back and forth in an ImageData object, which means that some browsers may not support this yet. It also means that there's the potential for some pretty severe precision loss, since all of the color values are compressed into a 0-255 range, sent to the main thread, and blended with the main image, which does another 0-255 compression. It would be far better to store and composite all of the color components as floats (or doubles, but Javascript doesn't give you the option. It falls somewhere in between), and copy those values over to the image after compositing. I tried this at one point, but the Web Workers kept dying and spitting out a strange "Not enough arguments" message. This is apparently a Chrome bug, but I have no idea how to get around it.
I also eventually dropped the idea of having a refractive sphere, simply because after many MANY iterations I still end up with either a black ball or a clear ball with an ugly black ring around the edges. You can still see the material class for it in the worker script, and if anyone wants to point out where I'm being stupid be my guest!
Anyway, as unimpressive as it is I did have a lot of fun putting this together, and hopefully someone out there at least finds it mildly interesting! For now, though I'm moving on to my next project, which may or may not be any one of the following: (haven't decided yet)
Yes, it's a browser demo (but not a WebGL one, sorry!) It's a Monte Carlo tracer, which means that the image starts out really ugly and gets better as more passes are applied. (Let it sit longer and it becomes prettier.) The image above is the result of letting it sit for 400 passes, and even then you can see a fair bit of noise. It's a very slow way of going about it, but it can produce spectacular results under the right conditions (and, you know, when you're not relying on Javascript to do it...)
Okay, so admittedly this is probably the least impressive demo I've done so far. It's your standard old boring Cornell box, and not even a really cool one at that because it lacks a refractive (glass) sphere. (More on that in a bit). There's a whole bunch of things "wrong" with it, and I may be tempted to come back and update it at some point, but the point of the thing was that I wanted to learn more about raytracing, and this little guy has served that purpose admirably.
A few fun "techy" notes: This started life as a Python port of smallpt, which I eventually gave up on when I realized that the GIL makes threading for this type of thing pretty useless. So I ported my port to Javascript (wait, aren't we moving backwards here?) mostly so I could use Web Workers, but it has a nice side effect of letting me demo it online. :)
The demo uses 4 web workers (though it's super easy to scale to more or less), each of which renders their own jittered version of the full scene. All passes are then send back to the main thread and composited into the final image. I'm actually passing the image data back and forth in an ImageData object, which means that some browsers may not support this yet. It also means that there's the potential for some pretty severe precision loss, since all of the color values are compressed into a 0-255 range, sent to the main thread, and blended with the main image, which does another 0-255 compression. It would be far better to store and composite all of the color components as floats (or doubles, but Javascript doesn't give you the option. It falls somewhere in between), and copy those values over to the image after compositing. I tried this at one point, but the Web Workers kept dying and spitting out a strange "Not enough arguments" message. This is apparently a Chrome bug, but I have no idea how to get around it.
I also eventually dropped the idea of having a refractive sphere, simply because after many MANY iterations I still end up with either a black ball or a clear ball with an ugly black ring around the edges. You can still see the material class for it in the worker script, and if anyone wants to point out where I'm being stupid be my guest!
Anyway, as unimpressive as it is I did have a lot of fun putting this together, and hopefully someone out there at least finds it mildly interesting! For now, though I'm moving on to my next project, which may or may not be any one of the following: (haven't decided yet)
- A WebGL accelerated version of this demo, to compare speeds
- A SketchUp to JSON exporter for quick prototyping of WebGL scenes
- An OpenGL ES 2.0 demo on Android (very tempting)
- A WebGL Material system
- Or possible something completely different! I have a bit of an itch to do something non-graphical for a bit, just to shake things up.
I've also got a couple of blog entries I want to do about some subjects I've found interesting lately, so hopefully there won't be as long of a gap before my next post.
Sunday, August 29, 2010
Setting up an OpenGL ES 2.0 dev environment for Android (The horror!)
It is a well known phenomenon that if you give a software developer (a REAL developer) any device which contains a CPU (and even a great many that don't) you will also install in them a great and uncontrollable urge to put their own programs on the damn thing. This urge cannot be satisfied by any old "Hello World" app either, oh no. It has to be something significant. Something that uses the device in a non-trivial way. Something that makes your peers say "Woah!" (The "Woah" factor is incredibly important, ask anyone.)
As such, being a developer and recently coming to posses a shiny new smartphone I've been dying to do some code for it for a while now. Finishing up some of my WebGL stuff and keeping up with my normal work (you know, the one that actually pays me) has prevented me from acting on it so far, and I still may not get a chance to code for it for a little while, but I finally had enough time lately to sit down and actually set up the SDK and play with some of the examples.
As such, being a developer and recently coming to posses a shiny new smartphone I've been dying to do some code for it for a while now. Finishing up some of my WebGL stuff and keeping up with my normal work (you know, the one that actually pays me) has prevented me from acting on it so far, and I still may not get a chance to code for it for a little while, but I finally had enough time lately to sit down and actually set up the SDK and play with some of the examples.
Saturday, August 28, 2010
Communication across language barriers
Had a neat experience while out walking my dog today. We came across a very kindly and very lost elderly Hispanic gentleman that flagged us down to ask for help. Since the first thing out of his mouth was "I no speak-a English very good." I was concerned that I would be fairly useless with whatever problem he was having. (Two years of Jr. High Spanish and all I can say fluently is "I don't speak Spanish".) Luckily, however, he was able to point to an address scrawled on a bus schedule and indicate that he was trying to reach that location. I knew where the address was, and fortunately he wasn't more than a couple of blocks off, but I was somewhat at a loss for how to communicate directions to him outside of vague hand gestures.
Then, in a moment of fleeting intelligence, I recalled the trusty little Android phone in my pocket that I had been listening to music on. Pulling it out, in under a minute I was able to call up Google Maps, punch in the address, have it map out the directions, and show this gentleman the results. Even though the map was in English a big blue line guiding you from where you are now to where you want to be is pretty universal. After studying the map for a moment a look of understanding and relief swept over him. He thanked me several times, a sentiment that I had no problem understanding, and headed off to his destination no longer lost and much happier for it.
For my part I was left with a mix of the warm fuzzies you get from helping another human being and wonder that we live in a day and age where I can hold in my pocket a tool that can completely transcend language and cultural differences and allow me to help someone in need. I don't care who you are, that's just cool!
As a programmer it's very easy for me (and, I think, others of my profession) to loose sight of why we surround ourselves with all this technology. We can easily fall into the trap of pursuing technology for the sake of technology. (I'm certainly guilty of that.) It's worth reminding ourselves once in a while that all of these spectacular devices and innovations are really there to serve one singular purpose: To make our lives better in some little way. Whether it does that by making some task a little easier, bringing us the information we need, making us safer, or just providing a few moments of entertainment, it's all in the name of improving our day to day existence. If we keep that in mind, magical things can happen.
Then, in a moment of fleeting intelligence, I recalled the trusty little Android phone in my pocket that I had been listening to music on. Pulling it out, in under a minute I was able to call up Google Maps, punch in the address, have it map out the directions, and show this gentleman the results. Even though the map was in English a big blue line guiding you from where you are now to where you want to be is pretty universal. After studying the map for a moment a look of understanding and relief swept over him. He thanked me several times, a sentiment that I had no problem understanding, and headed off to his destination no longer lost and much happier for it.
For my part I was left with a mix of the warm fuzzies you get from helping another human being and wonder that we live in a day and age where I can hold in my pocket a tool that can completely transcend language and cultural differences and allow me to help someone in need. I don't care who you are, that's just cool!
As a programmer it's very easy for me (and, I think, others of my profession) to loose sight of why we surround ourselves with all this technology. We can easily fall into the trap of pursuing technology for the sake of technology. (I'm certainly guilty of that.) It's worth reminding ourselves once in a while that all of these spectacular devices and innovations are really there to serve one singular purpose: To make our lives better in some little way. Whether it does that by making some task a little easier, bringing us the information we need, making us safer, or just providing a few moments of entertainment, it's all in the name of improving our day to day existence. If we keep that in mind, magical things can happen.
Thursday, August 26, 2010
Random WebGL related gunk
There's a few things I've come across in the last few days that I feel are worth pointing out to the WebGL community:
- Newer builds of Firefox have started validating the textures passed to generateMipmaps according to the OpenGL ES 2.0 spec. This means that attempting to generate mipmaps with non-power-of-two textures will start failing on you very soon! Please update you code/resources accordingly. (This already bit me with my Quake demos, which have now been tweaked accordingly.)
- WebGL___Array types are going, going, gone! Newer browser builds don't even have them defined, so make sure you are using the appropriate analogs from the Typed Arrays. Again, my demos have been updated to account for this.
- In an odd twist, whereas Firefox has been speeding up lately apparently Chrome is cracking down on crazy fast loops now. With the latest dev releases (7.xx) I've noticed that my Quake 3 demo is basically locked at 30fps, regardless of whether or not you check "Cap FPS". Curiously, this does not seem to be the case for my Quake 2 demo, which means that Chrome is actually limiting the internal message pump. Granted, it's a very stable 30fps, and I'd rather have a lower but stable framerate than a high but erratic one, so I'm not complaining. It did strike me as an interesting change, though. A bit of background on this one: For the Quake 3 demo in order to get the best framerates possible I used a hack picked up from Vladimir Vukicevic that continually posts messages to the page as a signal to draw (demo), which attempts to avoid some of the resolution limitations of setTimeout/Interval. This apparently causes severe performance issues if allowed to run rampant, however (as commenters on this site have pointed out) and so it's possible that this apparent capping may be Google trying to prevent abuse of the system. (Which is probably a good thing!) I'd love to know a bit more about the actual changes that took place in this regard, but in the end it appears that the timer-based method is the better way to go.
- Finally, in a bit of news that has nothing to do with WebGL whatsoever, I find this to be supremely amusing. Chrome envy, perhaps? :) It's especially funny in light of some Google-bashing that Microsoft did a few months back about how a single address/search bar was a bad thing for users privacy.
Tuesday, August 24, 2010
Firefox 4 beta 4 - Hardware Acceleration FTW!
I just wanted to jot down a quick note about something that made me VERY happy today! Firefox 4 beta 4 was released today, and one of the big features that it includes is (On Windows Vista/7 anyway) hardware acceleration via Direct2D. It's disabled by default, but doesn't take much to turn on (and certainly shouldn't be a problem for anyone who's been following WebGL).
First off, let me say that text rendering looks 1000% better when hardware acceleration is enabled. Seriously! I'm usually not one to care about aliasing in my text and whatnot but... WOW! The really exciting bit for me, though, was booting up my Quake 3 demo. With acceleration turned off I'm getting about 20-23 FPS (on par with previous betas), but with acceleration enabled I'm seeing 60-70 FPS! OMGWTFBBQ!?!
A 300% bump in render performance? That's insane! Awesome, but insane! Great work, Firefox crew! I can't wait to get this out of beta and into the average users hands.
(And now Chrome needs to get with the program! Seriously, looking at text in any other browser is gonna bug the crap out of me now!)
UPDATE: Ask and it shall be given, I suppose? I've turned the associated flag on, but can't see any difference in performance due to the apparent message pump cap I mentioned in a newer post. I'll see if I can find some better way of performance testing this later.
UPDATE: Ask and it shall be given, I suppose? I've turned the associated flag on, but can't see any difference in performance due to the apparent message pump cap I mentioned in a newer post. I'll see if I can find some better way of performance testing this later.
Spring (er.. late Summer?) Cleaning
As a heads up, some of my older demos (well, basically everything but the Quake 3 demo) are probably broken on newer browser builds at this point due to changes in the WebGL's API. (Hey, that's what you get for developing against experimental libraries!) Over the next couple of days I'm going to go back and fix them up (may even try to optimize the code a bit), so hopefully everything should be working again soon.
Until then, sorry for any broken code you may stumble across!
Update: So I've got all of the demos to stop throwing errors, but the Spore and Hellknight demo's aren't showing anything, even though they appear to load correctly. I'll continue looking into it, but in the meantime at least the Quake 2 and 3 demo's are running fine.
Until then, sorry for any broken code you may stumble across!
Update: So I've got all of the demos to stop throwing errors, but the Spore and Hellknight demo's aren't showing anything, even though they appear to load correctly. I'll continue looking into it, but in the meantime at least the Quake 2 and 3 demo's are running fine.
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