While the whole 3d movie/game craze seems to be ramping up, it really isn’t a new thing. We all recall those fancy red-blue glasses that were popular in theaters for a while, but I’m not talking about that. Passive 3d projection (using polarized glasses) has been around for a while too. Many people have figured out cheap ways to build these systems in their homes, but only recently have we seen media created for them in quantity. Now that you can buy 3D games and movies at your local box store, the temptation to have a 3d system in your home is much higher.
Here’s a great read on how to put together a fairly simple projection system that uses two identical projectors with polarizing filters. Basically, all you need are two projectors, two filters, a screen, and the glasses. There are plenty of tips for mounting and setup in the thread to help alleviate any headaches you might encounter.
This system is primarily used with a PC, because it requires two video feeds to function. A cost breakdown might make you wonder why you wouldn’t just jump on amazon and get a 32″ 3d tv for under $400, but sitting in front of that giant screen might make you understand.
This huge projection screen fills an odd alcove in [Dodge Boy’s] screening room. He built it himself for under $200. The materials, tools, and techniques make this a possibility for anyone who wants their own projection setup.
The frame is made of pine 1×3 dimensional lumber. To keep the fabric from touching the supports in the center of the frame he added quarter-round trim to around the perimeter. From there he painted it black and went for a test-fit. The bad news is that the drywall is neither perfectly flat, nor parallel/square. He ended up taking the trim off and ripping down one side of the frame. That did the trick and he went on to stretch spandex over the whole thing. The frame hangs from a french cleat on either side of the opening. From what we can tell, the surface is just fabric and not painted as we usually see with these setups.
[Dodge Boy’s] utility room shares the back wall of the screening room. That’s where he stores the HTPC which feeds he project, with an RF remote to control it through the wall.
Here’s another virtual sandbox meets real sandbox project. A team at UC Davis is behind this depth-mapped and digitally projected sandbox environment. The physical sandbox uses fine-grained sand which serves nicely as a projection surface as well as a building medium. It includes a Kinect depth camera over head, and an offset digital projector to add the virtual layer. As you dig or build elevation in parts of the box, the depth camera changes the projected view to match in real-time. As you can see after the break, this starts with topographical data, but can also include enhancements like the water feature seen above.
It’s a big step forward in resolution compared to the project from which the team took inspiration. We have already seen this concept used as an interactive game. But we wonder about the potential of using this to quickly generate natural environments for digital gameplay. Just build up your topography in sand, jump into the video game and make sure it’s got the attributes you want, then start adding in trees and structures.
Don’t miss the video demo embedded after the break.
Continue reading “Sandbox topographical play gets a big resolution boost”
The concept of having a digital gaming table got stuck in [RobotGuy’s] mind over the weekend and he managed to whip this up in no time using materials on hand. He already had a ceiling-mounted projector which just happens to reside immediately above the space occupied by his coffee table. By swapping that piece of furniture out for a white Ikea table, and adding a mirror to the projector he now has the virtual gaming surface he was looking for. The mirror mount is nothing more than a desk lamp that includes a spring clamp and flexible neck. He hot glued the piece of mirror to this, and attached it to the projector’s ceiling anchor. Since rear-projection screens are common, all digital projectors have the ability to mirror and rotate the image being displayed so that it appears on the table in the correct orientation.
We love the look, but this is really only one portion of a digital gaming project. We think the table needs some interactivity. We often see this done using infrared light processed by a webcam. That multi-touch option is not going to work with a standard table since the camera needs to be on the opposite side of a translucent surface. But if you don’t mind using a stylus this IR whiteboard technique would work.
DSLRs aside, the price of digital cameras these days can make it easy to consider just tossing your old one out when it breaks. [Leonidas Tolias] had another idea, and with a few broken cameras he had on hand he constructed a slick little pocket-sized projector.
The project started out as a pair of lenses from busted cameras and an Altoids tin in which he mounted them. The larger lens from a video camera was installed on the exterior of the tin, while the smaller of the two was mounted inside. Bits from disposable cameras were used to create a set of film reels, which he supports with some hand cut scrap aluminum. He made some test photo slides by printing some images on transparency paper, which he can cycle through using a film advancement rig he built out of string and a couple of gears.
While you won’t be using this projector for your next boring PowerPoint presentation, it does work pretty well as you can see in pictures on [Leonidas’] site.
It’s Friday night and these guys are driving around town looking for a good spot to play a head-to-head game of Snake. It’s not that they need somewhere to sit (they travel with a couch and floor lamp for that purpose) it’s that they’re using a projector and camera to make a game out of their surroundings.
A white Mystery-Machine-style van has room for everything they need to make the traveling arcade happen. A mobile power supply provides juice to the camera and projector. To get started, the system takes a high-contrast black and white photo of the surface in front of it. Everything that appears below the white threshold becomes a wall on the game board, everything else is a playable area. Obstacles are formed by windows, doorways, pipes, signs, pieces of foam board the guys hang on a wall, and even your body if you stand in the way during scanning. From there the guys each grab a joystick and play the hacker-favorite game of snake.
After the break you can watch a description of how the system works. Continue reading “Snake-the-Planet makes a game board out of your surroundings”
If you are thinking of building your own flight/racing sim setup at home, you might want to check this out. [Alex] from the Garoa Hackerspace in Säo Paulo, Brazil put together a slick setup that makes projector image calibration a breeze.
When building a wraparound screen for such a simulator, you are likely to run into problems with both overlapping images and distortion from the curved projection. There are projectors that can easily adjust themselves to work in this sort of setup, but they are often very expensive, so [Alex] thought he would build a solution himself.
After studying a paper written by [Johnny Chung Lee] in 2004, he built a prototype display calibrator last year that used similar, though slightly tweaked methods to get the job done. This time around, [Alex] has improved his calibrator, making the process more precise and a bit quicker.
Light sensors and an Arduino are attached to the back of the projection medium, and a large broad scan of the screen is performed by the projector. His code then triggers an additional sweep of each corner to better estimate the exact edges of his projection surface. Since the video is tweaked in software rather than relying on the projector hardware to handle the task, the result is cheap and very accurate.
Don’t take our word for it though, check out [Alex’s] video demonstration below to see his calibrator in action.
Continue reading “Projector calibration on uneven surfaces made easy”