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This weekend, learn how to draw on buildings. Laser Tagging is a non-destructive way of using a laser, video camera, computer and projector to apply graffiti to buildings! It’s a lot of fun!

You’ll see the GRL Vienna guys Michael Zeltner and Florian Frühauf who rocked Berlin with 5500 lumens of laser graffiti awesomeness. They would like to extend a thanks to Theo Watson and Evan Roth and James Powderly of GRL who came up with the idea, first implemented it and put it out there in the public domain.

The GRL NYC peeps recently put out a tutorial on starting your own GRL. – Link

Lasers, like power tools, can be dangerous. You’re responsible for your own safety!

  • Bonnie

    This is beyond awesome! Those interviews are great!

  • Paul

    The original GRL project was the source of inspiration for our final year project at the University of Michigan! We made a smaller implementation entirely on an FPGA, and our project page (with Youtube videos) is at

  • John

    The podcast on iTunes has no sound!

  • Njakol

    Same as above, no sound in iTunes!

  • Njakol

    Same as above, no sound in iTunes!

  • Dave

    In case this helps anybody… the program was giving me “java.lang.UnsupportedClassVersionError”. Simple fix: rearrange the J2SE versions in the Java Preferences.

  • gunterhausfrau

    Is the link for GRL Vienna broken?

  • Bre

    I figured out the sound problem and replaced the mp4 and so the link is back! It may take a day for it to re-propogate to itunes :(.

  • ramriot

    Great idea, I really wanted to know how it was done, pity ‘Learn how to do laser graffiti’ does not tell you.

    Please if you are able, do another podcast telling us how the projector works, because that is the MOST important bit.

    Also a bit pissed off because no sound on itunes download, made me reboot twice before trying another file.

  • gunterhausfrau

    Good to see that jesus spam gets through.


    back to Make- When do you think the non-mac version of the program will be around? Windowz or Linux?

  • Cody

    Already done. (For a while, actually.)
    That page has the source and a windows download, along with instructions.

  • Cody

    ***Disregard that***

    There was an update, to version 2.0

    Sorry, I seem to have missed that.

  • John

    Having now watched it on the embedded Flash movie, I see what ramriot means. After reading the PDF, I think that it works by having a normal projector and a normal laser pointer, and the software tracks the position of the laser pointer using a video camera. You then ‘write’ using the laser pointer and it projects a line/mark where-ever it sees the laser dot.

    This podcast really needed a lot more explanation on exactly what you guys were doing. I think you’ve assumed that everyone watching this knows all about GRL and their projects and you’re just giving a video demonstration of it.

    Pretty weak podcast, and certainly not a ‘Weekend Project’, since there was no project here.

    (That’s not to say anything against the actual set-up those guys are using, which is neat.)

  • andrew

    This is useless and vain. It doesn’t show any actual equipment or the people using the system.

  • John Stoner

    Yeah, I’m really unsatisfied with the video portion of this: getting the software to work should be the easy part. You really need to show the projector/camera setup. I imagine there’s got to be problems I couldn’t forsee, and tricks to getting it right. Show us.

  • Kevin O.

    I tried the laser tag (C++ version) and it seemed to crash a lot on Vista. I got some of the processing stuff going, but am having trouble with the Java3D (Vecmath) imports. Any clues? There is a windows version of JMyron and it seems to work.

  • Jeremy Ruhland

    I got it to work, I’d stick it on the flicker pool but I lack an account and this is a video. I guess this is the next best place to post it.

  • gunterhausfrau

    anyone catch the flash of text in the video?

  • Josh

    BRE you are my hero!i will but some pics up of this i just need the money and time it looks esey (i hope my mom will not get mad at the tho XD)

  • f*

    ok, i will try to answer a few of the most comon questions since some stuff might not be clear …
    first of all, the video is a bit short and it might be a little bit understand, but its really not as hard as you think. and we will answer your questions and help everyone as good as possible so you can also get it to work.
    first of all, we dont always use the same equipment. that means we only have a laser and a macbook. and we use whatever projector we get. and depending on that/on how strong the projector is you can do small or big buildings. the eq. you see in the video is a 60mw laser, a macbook (camera is the macbook isight cam) and a sanyo 5500 lumen projector.
    it also works with an 1000 lumen projector but its not as bright and you cant go as far. so, if you have an old projector at home for watching dvds/movies, you can totaly use that one! of course it will have to be dark/it wont be as bright, and you will only be able to do small surfaces. so, any projector works, the better it is (more lumen) the bigger you can go!

    laser: we use a 60mw laser. its green because the program tracks a green dot (so you can say the program is writen for a green laser) it is possible to do it with a blue or red one,but green works the best (if you really wanna know how to change it ask)
    you can order them on the internet, and also like the projector..a 30mw laser will also work or maybe even one with less mw, but the stronger the laser, the further you can go and so on …

    cam: we mostly use the macbook/isight cam cause its easy and it workes fine. so probably any web cam will do.

    so, how it works.
    you draw on the building with the laser(pointer)
    the cam tracks the green dot
    the progam tells the projector where the green dot is and the projector folows it. and thats how you draw stuff : )
    thats a pretty easy and fast non techy explaination but i hope you get it.

    if you have any troubles gettin it to work, if you need help or have any questions. just ask us.
    [email protected]
    its really not that hard and we wanna help everybody as good as possible : )

    regards, f*

  • xx


  • Tom

    You can only see the image if your looking from the one spot, everyone passing by sees nothing.

  • a random John

    The GRL Laser Tag project was the inspiration for my entry in the Make Halloween Project contest. Note that I lost. Probably because I didn’t submit a proper instructable. I used a laser, webcam, and projector to make a Halloween themed game in front of my house:

  • Bomboy
  • Gregory

    Are there any legal issues about doing this?

  • reed

    when i go to put laser maker and jmyron in to the processing libraries my macbook tells me it can’t beacuse libraries cannot be modified
    help please

  • dakkl

    I get a C:/DOCUME~1/Owner/LOCALS~1/Temp/build63954.tmp/ Semantic Error: Type “Vector2d” was not found

    error whenever i try to hit “present” in my Processing program, any suggestions?

  • Kody

    I’ve followed the instructions as best i can (i couldn’t open the PDF so i’m kinda blind but can anyone help me figure out why i’m getting this error message “the package ‘javax.vecmath’ does not exist. you might be missing a library” when i attempt to present LaserMarker in processing?

  • d man

    i tried to open processing but it says to download java kit v1.5.0 but i cant find ti any where can you help.