# Get ready to have your mind blown: Projection Mapping **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [September 27, 2013, 12:46pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795 "2013-09-27T12:46:21Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Patty\_O\_Furniture](https://avatars.discourse-cdn.com/v4/letter/p/96bed5/32.png) [@Patty\_O\_Furniture](https://boards.straightdope.com/u/Patty_O_Furniture)\ **Post date:** [September 27, 2013, 12:46pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/1 "2013-09-27T12:46:21Z")
[Link to video of amazing projection mapping performance](http://www.botndolly.com/box). Even before I watched it, I sort of gathered from the name that this was going to be some sort of performance art thrown onto a screen by a projector. But… _whoa_. I read the wiki page on PM, but I still can’t quite figure out how they managed to prevent the guy from casting shadows onto the flat projection surfaces when he walks in front of them. And how come there isn’t all kinds of incidental light from the projector spilling over onto the back of the studio? When you watch this, you really have to keep reminding yourself that those are flat planes being moved around by giant robot arms. ---
**Author:** ![Uber\_the\_Goober](https://avatars.discourse-cdn.com/v4/letter/u/58956e/32.png) [@Uber\_the\_Goober](https://boards.straightdope.com/u/Uber_the_Goober)\ **Post date:** [September 27, 2013, 2:50pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/2 "2013-09-27T14:50:46Z")
Not projectors, but flatscreen tv’s? ---
**Author:** ![Lanzy](https://avatars.discourse-cdn.com/v4/letter/l/74df32/32.png) [@Lanzy](https://boards.straightdope.com/u/Lanzy)\ **Post date:** [September 27, 2013, 2:58pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/3 "2013-09-27T14:58:27Z")
An act on AGT did something similar but this is much better. ---
**Author:** ![JKilez](https://avatars.discourse-cdn.com/v4/letter/j/e5b9ba/32.png) [@JKilez](https://boards.straightdope.com/u/JKilez)\ **Post date:** [September 27, 2013, 3:41pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/4 "2013-09-27T15:41:20Z")
That was fantastic. I am guessing that they are projecting on the screens from behind (within the dolly-bots). This requires a static (or pre-known) observer position to keep the perspectives correct. I do not think this would work for a general audience. ---
**Author:** ![Don\_t\_Panic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/don_t_panic/32/398_2.png) [@Don\_t\_Panic](https://boards.straightdope.com/u/Don_t_Panic)\ **Post date:** [September 27, 2013, 3:55pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/5 "2013-09-27T15:55:27Z")
Yes. Basically flat-screen TV’s, and the perspective is matched to the motion of the camera. Looks awesome! ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [September 27, 2013, 4:17pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/6 "2013-09-27T16:17:43Z")
> [@Martian Bigfoot](#): > > the motion of the camera Doesn’t the motion have to be carefully planned as well? Is the camera controlled by another one of those robots? I don’t think it can be done by a human holding it. Looks impressive, but like those 3D chalk drawings, only does so from one very specific viewpoint. ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [September 27, 2013, 4:21pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/7 "2013-09-27T16:21:35Z")
Damn! ---
**Author:** ![Steken](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@Steken](https://boards.straightdope.com/u/Steken)\ **Post date:** [September 27, 2013, 4:22pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/8 "2013-09-27T16:22:20Z")
The camera is, presumably, on a motion control rig. ---
**Author:** ![Hypno-Toad](https://avatars.discourse-cdn.com/v4/letter/h/b2d939/32.png) [@Hypno-Toad](https://boards.straightdope.com/u/Hypno-Toad)\ **Post date:** [September 27, 2013, 5:14pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/9 "2013-09-27T17:14:23Z")
I could see this kind of technology being used in advanced theme park rides, if it isn’t already. Maybe this is the crude, flickering genesis of the holodeck. Also, those aren’t flat screen TVs. They’re just flat surfaces being projected onto. That’s why the floor is able to interact with them as part of the performance. ---
**Author:** ![steronz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steronz/32/11765_2.png) [@steronz](https://boards.straightdope.com/u/steronz)\ **Post date:** [September 27, 2013, 5:35pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/10 "2013-09-27T17:35:19Z")
If they were using TVs this wouldn’t have anything to do with projection mapping, so I think we can assume that the robots are holding normal boards, probably painted black with some kind of IR LEDS on the corners. I’m having trouble finding a good video, but [here’s a normal guy](https://www.youtube.com/watch?v=bvvy86zvoX4) with a normal projector going through the steps required for some simple projection mapping onto a couple of white boxes. In this case, an IR receiver mounted to the camera can identify the location and orientation of the boards. Software then determines the shape of the projection required so that the projected image only shows up on the boards, and with the right perspective (since the receiver is mounted to the camera it knows where the camera is in relation to the boards). If you were standing in the room a few feet away from the camera, it wouldn’t look right. Also, with this method there’s no reason for the camera to be on a robot itself. ---
**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\ **Post date:** [September 27, 2013, 5:37pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/11 "2013-09-27T17:37:47Z")
> [@Hypno-Toad](#): > > I could see this kind of technology being used in advanced theme park rides, if it isn’t already. Maybe this is the crude, flickering genesis of the holodeck. I thought Disney was doing something like this with their haunted house but maybe not. If you google “projection mapping Disney” they are definitely using it at their theme parks already! ---
**Author:** ![steronz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steronz/32/11765_2.png) [@steronz](https://boards.straightdope.com/u/steronz)\ **Post date:** [September 27, 2013, 5:38pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/12 "2013-09-27T17:38:10Z")
> [@Patty\_O\_Furniture](#): > > I read the wiki page on PM, but I still can’t quite figure out how they managed to prevent the guy from casting shadows onto the flat projection surfaces when he walks in front of them. And how come there isn’t all kinds of incidental light from the projector spilling over onto the back of the studio? Well if I’m wrong about the IR emitters on the projection surfaces, it may just be doing visual tracking. If so, it can track the location and shape of his arm and stop projecting over that area in real-time. If that’s what’s happening, that’s an impressive response rate. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [September 27, 2013, 6:59pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/13 "2013-09-27T18:59:22Z")
If you liked that you might like Curtis Steiner’s 1000 blocks: [Curtis Steiner | 1,000 Blocks](http://www.curtissteiner.com/blocks/) ---
**Author:** ![2gigch1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/2gigch1/32/3313_2.png) [@2gigch1](https://boards.straightdope.com/u/2gigch1)\ **Post date:** [September 27, 2013, 8:43pm UTC](https://boards.straightdope.com/t/get-ready-to-have-your-mind-blown-projection-mapping/669795/14 "2013-09-27T20:43:53Z")
Thank you! That was 5 minutes well spent.