Hacker News new | comments | show | ask | jobs | submit login
Recreating the “Asteroids” graphics with a single-beam laser projector [video] (youtube.com)
97 points by eddyg on Mar 18, 2017 | hide | past | web | favorite | 16 comments

4 Watts! That is a ridiculous amount of power for a project like this. No wonder the screen is so bright!

For those of you who want another point of comparison for how powerful this laser is, advanced LIGO detected gravitational waves for the first time in 2015 with an average laser power of only 23W[0] (though we use a lot of tricks to boost the power of the beam, like Fabry-Perot cavities in the detector arms).

[0] https://www.advancedligo.mit.edu/aug_2016_news.html

On early pre-production Atari vector games, you could burn a hole in the phosphor all the way to the glass if you left the electron gun active too long without moving the beam. They added a "spot killer" circuit that turned the beam off if you left in place too long.

(From "The Secret Life of XY Monitors": http://www.jmargolin.com/xy/xymon.htm)

I did a really crappy version of this in undergrad years ago, also with 4 watts. I also projected pong onto skyscrapers in Atlanta. I have several videos of this at http://lasers.io

In the pong video (https://www.youtube.com/watch?v=x034jVB1avs) I find it absolutely hilarious that you practically just grabbed a random guy to play it while you filmed.

I love this guys projects. I have a friend that collects vector graphics arcade machines and he got me into them a few years ago. I played them plenty as a kid but never really thought about how they worked before. After learning about them, one of my first thought was how it was like a laser show but never followed up to see if anyone had done anything like that. When this video showed up in my feed last week, I was ecstatic. I'm really hoping to find the time to dig into doing something like it. I'd love to see a comeback of arcade machines that are very hardware specific instead of using generic displays and controls.

Unfortunately, the mirror galvos are much slower than moving an electron beam around. So he can't do a full Asteroids game. It would be straightforward to do Asteroids on an analog oscilloscope, but the screen is kind of small.

(4 WATTS of laser power? He's going to burn through his screen if the beam stops moving.)

High power is necessary for brightness while scanning over a large surface area. Most laser projectionists know what 4W will do if left still. I'd be more worried about my eyes if I were to look at a single 4W point on the wall than even the damage to the screen!

As far as flicker and point rate is concerned, it's possible to divide rendering work between projectors.

Like the most amazing quake port ever? :) https://www.youtube.com/watch?v=aMli33ornEU

Cute. They're getting analog output from slow audio D/As, which is why the graphics are so shaky. The scope is orders of magnitude faster. Here's someone who used the output from a VGA port, which has megahertz-bandwidth D/As on the output end. Much better.

[1] https://www.youtube.com/watch?v=EfBwz_SiK8s

Yeah, we tried hooking an original system to a laser projector at a hack night for the Centre for Computing History back in 2010 and as you say found the galvos just couldn't keep up :/


A few seconds from 1:42 catches the work: https://www.youtube.com/watch?v=uUEPSuQ6PMs

Not quite as cool as laser beams, but if you have an oscilloscope with an x/y mode: https://www.nycresistor.com/2012/09/03/vector-display/

I'll plug Sebs Creative Coding podcast then since the video doesn't seem to haha.


This is the real intersection of games and art, for me. I'd love to see it in person.

Okay, real talk, where do I get / buy / make one?

Try the Photon Lexicon forums. There are lots of knowledgeable people there, and it's easy to price out a build (or buy a projector).

A lot of us work on open source bindings. (Much of my laser code is in Python and Rust and is available on Github, linked in my profile.)


Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact