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Game Dev, Physics, Science

GDC 2013 – Tuesday is Physics Day ….kinda

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Tuesday was Day Two of the Math and Physics for Game Programmers tutorial. Monday was all about the mathematics, and Tuesday was supposed to be all about the physics. There was one great talk from which I was able to extract a better understanding of configuration space objects, but the rest of it was …meh. As with yesterday, those talks which were edited and tweaked from last year showed improvement, those that weren’t still sucked.

The day started out with a demonstration of a simulation of a Go stone. …yeah. A stone. It seemed that the speaker, Glenn Fiedler from Sony Santa Monica, was simply pleased with himself that he’d recreated the wheel. He went through the process of creating his stone model, then he described the basic translation and rotational dynamics he deployed without discussing the specific details. It might have been a more fruitful talk if there were more details in how he was integrating the motion, why the integration works the way it does, and described the fundamental principles involved. Although his simulation worked pretty well, during talk, there were a few conceptual errors, especially about the properties of the moment of inertia tensor. He kinda had the right idea, but not really. Granted it’s a tough thing to pick up on your own, but if you’re giving a talk on the topic, you should have a genuine and thorough understanding of the topic.

1364390049722The second talk of the day was “The Separating Axis Test” by Dirk Gregorius from Valve. Gino van den Bergen of Dtecta gave a talk last year on collision detection using Minkowski differences and configuration space objects, but I must admit that the process was still fuzzy to me. Dirk’s talk on the issue really helped. Don’t get me wrong, Gino is the man and does a great job, and when his talk came up later in the afternoon, I was able to grasp a bit more about how CSOs work. I doubt that they’ll make it into the PHYS191 course in a formal way, but I may put a bonus section on it in the textbook this summer if for no other purpose than to ensure that I understand it correctly myself. No better way to see if you really understand something that to try to teach it to someone else. The rest of the afternoon was rather blah, unfortunately. Dirk’s and Gino’s talks certainly made up for the mediocrity of the others.

Since the Expo Hall isn’t open until Wednesday, during my downtime between when I left the physics tutorial and supper, I worked on taking some photos. I took some of this earlier in the morning on my way to breakfast, but was disappointed with the results. Yes, I was at the Rally in the 100 Acre Wood, but I didn’t work on many panning shots there so I’m really out of practice. That showed as I tried to get some panning shots of cyclists and streetcars. I gotta get back into proper form before the Kansas City Region SCCA season starts and definitely before the first IndyCar event I’ll work, the Indianapolis 500 Mile Race. Definitely have to have good panning skills there.

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Of course, one thing that is ever-present in San Francisco around the touristy areas are the street performers. Most are simply annoying, but there are some, like this duo, that really sounded good!

One of the coolest new things I’ve seen at GDC so far is the Video Game History Museum alcove. They have several coin-ops including one of my favourite games, Asteroids! (where’s my two-liter of Shasta and my Rush mix-tape?) The also had several classic consoles, some well-known, others not as well-remembered. Of course they had the Atari VCS (later known as the 2600), but they also had a Vectrex! That’s a tough find! There weren’t too many of these machines made, and even fewer of them have survived in playable form.

Chinatown_IntricateGraffiti_smThe day ended with a stroll through Chinatown, a requisite visit every year. There wasn’t anything new, really. The same peddlers were peddling the same cheap, cheesy crap. One change that greatly disappointed me was the defacement of one of Banksy’s pieces. I now feel very fortunate to have imaged this a few years ago. It was a really cool work, but now in spite of the plexiglass overlay placed in hopes of preserving the street art, it’s been covered with simple scribbles of white spray. It’s a damn shame.

Next post will be all about swag! The Expo Hall opens on Wednesday, and with a light session load today, I’ll be cruising through as much as I can, collecting as many goodies as I can.

Game Dev

GDC 2013 – Monday Math Madness

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2013-03-24 07.44.26It was a bit sketchy, but we finally made it to San Francisco for the Game Developers Conference (GDC). The insanely late snowfall in Kansas City resulted in our flight being delayed, but at least it wasn’t cancelled. This was the first time I have been through the deicing process. It was interesting, if time-consuming. Once we were in the air and above the clouds, everything seemed far less dreary and dreadful.

Upon arrival, we did the usual things: take the noisy BART ride to Powell station, leave our bags at the hotel, wander aimlessly until check-in time, check-in, get our GDC badges when registration opens, and celebrate with Naan & Curry. I’ve been to many different conferences, some big, some small, and the folks running the GDC have the process down to a science! Once registration opened, we were in and out with our badges within a couple of minutes. It was amazingly quick!

PowellTurnaround_smMonday morning also began in the traditional way with me waiting for the rest of the crew down by the cable car turn-around at Powell St taking photos. I know that I end up taking a lot of the same types of shots year after year, and I need to work on my variety, but I just dig that spot so much for imaging the cable cars. Once everyone has mustered, we head off to the best breakfast joint in the area, Mel’s Drive-In. Mel’s is one of the best places around to have breakfast, and with steak-n-eggs only costing $7.99, it’s tough to beat the price, especially in San Francisco!

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Every year, I go to the Math and Physics for Game Programmers. Monday is all about the mathematics and Tuesday is all about the physics. The topics and presentations are usually the same with minor tweaks from year to year, but today the presentations were outstanding. Squirrel Eiserloh from Southern Methodist University gave his usual talk on interpolations and splines, but with more focus and less superfluous material than last year. Here’s last year’s presentation: http://essentialmath.com/GDC2012/GDC12_Eiserloh_Squirrel_Interpolation-and-Splines.ppt. Be sure to also download his OpenGL-based demo tool. It’s a fun little app for exploring the properties of the various types of curves and splines he describes in his talk.

The second talk of the day was by Jim Van Verth, who is notorious for losing his voice at GDC. Normally, this takes about half a day, but this year, he was tight and scratchy from the get-go. His energy level this year, however, was much higher, and he was a much more engaging speaker than in the past. He also did a LOT of work on his presentation. I found his previous presentations on rotations and quaternions rather unenlightening. This year he knocked it out of the park! I think I actually get this quaternion stuff! It helped that he related them back to quantum physics and spin groups, with a nice sprinkling of hyperspatial geometry thrown in for good measure. You know it’s a good conference when you hear a serious discussion of hyperspheres and how to visualize them. His 2013 slides aren’t up just yet, but you can check out his site, http://www.essentialmath.com/ in a couple of weeks. He’ll have them up before too long. If the rest of the conference were cancelled right now, I think that my finally understanding the nature, behaviour, and deeper mathematical roots of quaternions makes the whole trip worth it. The rest of the week is gravy!

Tomorrow is all about the physics! Last year, there were some great talks regarding integration methods and collision detection. Hoping that this year, I can finally wrap my head around this configuration-space stuff.

Astronomy, Photography, Science

Comet PanSTARRS Is Tricky But Worth The Effort

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There’s a comet in our skies this week! With Comet PanSTARRS being so close to the Sun and therefore so low to the horizon, seeing this first major comet of the year is tricky! The comet is viewable about a half hour to an hour after sunset, but don’t expect it to leap out at you. You’ll have to look hard for it. With the clear skies last night, I tried to see if I could spot the comet without aid, and it was tough. I couldn’t see it at all at first, not until the skies darkened considerably. I had to wait until a little before 8pm as Orion was starting to become visible before I could find the comet. Even then, I had to look very closely at the sky maps published at Sky & Telescope’s website to make sure I was looking in the right spot. Binoculars really helped. My 200-500mm zoom lens helped more! I finally did get an image of Comet PanSTARRS along side the Moon.

The image I captured was with my Nikon D7000 (a 1.5x crop sensor) with a focal length of 200mm (300mm 35mm equivalent) at f/5.6, a shutter speed of 2 seconds, and at ISO 800. I did some noise reduction in Photoshop, but didn’t do anything else to the image. I like how the night side of the Moon is visible when it’s just an ultra thin crescent like this.

Astronomy, Science

Paul Tebbe and The Sun’s Analemma

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When I first started teaching here at JCCC, I taught the General Physics I and II courses and the Physical Science course on occasion. In 1995, I was asked to fill in for a partial semester for Professor Paul Tebbe teaching Astronomy. Talking about astronomy, and especially astrophotography and photometry, with Paul was always a treat for me; his enthusiasm for astronomy was absolutely contagious! I especially enjoyed watching Paul talk to the public during the Evening With the Stars program and seeing his enthusiasm spread throughout his audience.  Paul’s wife, Dr. Anita Tebbe, found and sent to me a video of Paul talking about the analemma plank that’s part of the Galileo’s Garden sculpture back when it was still in the quad next to where the fountain is now.  Paul passed away in the Fall of 2000, but his passion for astronomy can still be seen and felt here at the JCCC campus and our observatory now bears his name in honor of all the hard work he’s done to build the Astronomy program.