Spatial Practice - Multichannel Audio

My main objective in using the surface was for multichannel audio. I had found a hifi sub in hard rubbish, so had saved it for a project that would incorporate more than 2 channels.

The powerlead was cut. I braided and soldered the end of a "figure 8" IEC lead to it and used electrical tape to insulate the connections.

 It worked!

2001, a space(tial practice) odyssey.
[Audio in the clip is being produced by the speakers + sub]

Spatial Practice - Research: IR Illumination Methods

After trawling the NUI forums I discovered the best, cheapest method for providing enough infrared light is via Infrared LED Illuminators, specifically ones used for Nightvision/Security cameras.

4 of these placed evenly above the surface should allow the projection surface to be receptive enough to use in the absence of room light/lamps.

http://dx.com/p/ir-48-led-infrared-illumination-light-for-night-vision-dc-12v-500ma-15235


Pending the arrival of this order I will now have to abandon any attempts at visual feedback on the surface, which wont affect its functionality.

Spatial Practice - Webcam IR Mod Troubleshoot

Thinking that perhaps the portion of the old 35mm negative used to make the IR filter may be not as effective as a piece of unprocessed film, I once again took apart the webcam, replacing the old filter with the new one.

I reassembled it and plugged it in, the display showing its sensitivity to all light far more diminished, rather than just light below the IR spectrum. 

Being basically unusable in this state I disassembled it a third time and reassembled it with the first filter I'd made once again.

Grumble grumble, debugging is frustrating.

Spatial Practice - Visual Feedback: Troubleshooting

Had success with projecting the laptop screen onto the same surface that I was tracking touch movements. I was ready to move on to calibrating the surface when I encountered issues with providing enough backlight from the lamps to create the necessary solid shadows on the surface while keeping it dark enough to see the projected image. see below.

After scouring online for many hours I was unable to find a solution, so I mailed the creator of this particular design in the hope of discovering a solution to the issue.


Hey Seth,

I'm getting into MT surfaces and discovering your site has been invaluable, many thanks!

I'm building the MT Biggie and have had success so far in using CCV, tracking blobs and sending them via Osculator to ableton live. However the lighting required to achieve good results has made the projection surface far too illuminated to actually see the projection! I'm stuck as to how to achieve a balance of both solid backlighting and a dark enough projection surface to effectively throw onto.

I'm currently waiting for my registration on the forums to be approved so I thought I'd shoot you a quick message here if you're able to offer any ideas? 

Thanks again!
Jay

Spatial Practice - Multitouch Assignment via OSC

First experiment, using the surface to control the mouse pointer.

Open Sound Control (OSC) is a content format for messaging among computers, sound synthesizers, and other multimedia devices that are optimized for modern networking technology. Bringing the benefits of modern networking technology to the world of electronic musical instruments, OSC's advantages include interoperability, accuracy, flexibility, and enhanced organization and documentation.

Spatial Practice - Signal Test

Initial test worked.

By using a mirror to aim the webcam's view up toward the acrylic sheet and illuminating it with incandescent light (containing the infrared spectrum) I was able to pick up movement in the CCV application and route that to Osculator, ready to be mapped to MIDI in Ableton.

Spatial Practice - Webcam Modification

Picked up a Logitech QuickCam from Gumtree for a fiver.

After hours of trial, error & websearching finally came across a solution for using old USB cameras with OSX. 

http://webcam-osx.sourceforge.net/

I can get it to display via Macam in HackTVCarbon and Skype which will do for now.

I dismantled the webcam, following these instructions for altering the lens to only accept infrared input.

Spatial Practice - Research: Front Diffused Illumination

The simplest option appears to be FDI, as it does not require an IR light.


Front Diffused Illumination:
In Front DI, infrared light is shined at the screen from above the touch surface. A diffuser is placed on top (preferred) or on bottom of the touch surface.  When a finger or object touches the surface, a shadow is created under the object and seen by an infrared camera below the surface. This method is what the MTmini uses, but without the need for infrared light (since there is no visual display to remove). The MTbiggie also uses this technique. An image is displayed by using a projector connected to a computer pointed towards the projection material.

from: http://sethsandler.com/multitouch/frontdi/


The model I will be attempting is known as the "MTBiggie" which is a larger (biggie) size multitouch (MT) surface that allows visual feedback via projection.

PARTS LIST

• 2 chairs (or anything to prop up the acrylic)
• Piece of clear, flat sturdy material (ie. glass, acrylic, plexiglas)
• Projection material (ie. printer paper, tracing paper, rosco projection material, etc)
• Infrared webcam/camera
• Computer (dual core recommended, but not required)
• Projector
• Mirror

Spatial Practice - Parts Acquisition Acrylic Piece

50cm Piece of Acrylic donated.

Spatial Practice - Research: Multitouch Techniques

Upon further research there appears to be several different approaches to creating a Multitouch Surface.

Other than Optical (which is the approach I will be taking) there are Capacitive, Resistive, Acoustic and others.

The most popular optical techniques are as listed below:

• Frustrated Total Internal Reflection (ie. Perceptive Pixels)
• Rear Diffused Illumination (ie. Microsoft Surface)
• Front Diffused Illumination (ie. MTmini, MTbiggie)
• Diffused Surface Illumination
• Laser Light Plane
• LED Light Plane

(image from http://sethsandler.com/multitouch/)

Spatial Practice - Parts Acquisition Projector

Borrowed this small projector from a friend, this should be perfect to display feedback onto the surface.

Spatial Practice - Software Interface

Before approaching the construction of the surface my initial thoughts of the software side of the interface could be a node based system (ala Audiomulch's Metasurface - http://youtu.be/U3egshfGd7Q)

Though not being a registered user of AM and preferring to keep the software environments I use streamlined I've found a similar implementation in Max4Live (Ableton) which will suit. 

http://little-scale.blogspot.com.au/2012/09/node-based-virtual-midi-controller.html

Spatial Practice - Arduino (Clone) Microcontroller Unboxing

Arduino-Compatible Board

Fully Compatible to Arduino Nano V3.0 ATmega328P-AU

Headers / Pin Heads non-soldered, leave room for DIY flexibility. 

Product Details:

ATmega328 Microcontroller

Bootloader installed, ready to upload sketches from Arduino software

Flash Memory 32 KB

EEPROM 1 KB

Specifications:

Microcontroller	ATmega328P-AU
Operating Voltage	5V
Input Voltage (recommended)	7-12V
Input Voltage (limits)	6-20V
Digital I/O Pins	14 (of which 6 provide PWM output)
Analog Input Pins	8
DC Current per I/O Pin	40 mA
DC Current for 3.3V Pin	50 mA
Flash Memory	32 KB of which 2 KB used by bootloader
SRAM	2 KB
EEPROM	1 KB
Clock Speed	16 MHz

Spatial Practice - Homebrew Multitouch Interface Ideas

Attempting to get back on target with a visual project, I am now considering constructing a DIY multitouch interface.

These things were mindblowing back in 2006 in the days before iPads and tablet devices but I still think that a hand constructed multitouch surface from repurposed materials serves as a very compelling centrepiece for an interactive spatial environment housed in an arts space. It also subverts the predisposition toward these interfaces being hi-tech and contained only within portable consumer devices.


Projects:

http://hacknmod.com/tag/touch-screen/

http://mods-n-hacks.wonderhowto.com/how-to/make-multitouch-table-computer-pad-276756/

http://mods-n-hacks.wonderhowto.com/how-to/make-cheap-multi-touch-pad-like-macbook-air-245061/



Whiteboard + Wiimote:

http://mods-n-hacks.wonderhowto.com/how-to/hack-cheap-multi-touch-whiteboard-using-wiimote-162856/

$2 Multitouch

http://mods-n-hacks.wonderhowto.com/how-to/make-almost-free-multitouch-pad-177380/

Spatial Practice - Other New Ideas

SD Card Sample Player Hack

http://www.bassmaker.co.uk.webserver1.reidhosting.co.uk/sampleplayer.html

Must do this project! but perhaps not visual enough for this course sadly! :(

Spatial Practice - New ideas

Considering the possibilities of a new project due to dead hardware. 

A shame, considering I was enjoying exploring Magnetic Tape and EM Fields from my last project and was excited to continue this into manipulating visual material encoded on tape (VHS).

I had been wishing to explore Discman bending, again exploring the theme of abandoned technology.

Below are a couple of the most compelling projects I've come across:

r20029 - Sony Discbitch

http://r20029.wordpress.com/2012/10/09/cd-player-circuit-bending-intro/

Lo-Fi Ninja's Circuit Bent Discman

Interesting article "Data Discman"

http://ambiguities.wordpress.com/2012/07/07/the-data-discman-of-american-experimental-fiction/




Discman Bending Tips

http://forum.noiseguide.com/viewtopic.php?t=3376&sid=715994cbce912b73db7ba32001c7ea18

Spatial Practice - Telephone Induction Coil Recording

First recording through one of the telephone induction coils. 

Sources: laptop & iphone performing various tasks to generate audio.

NB: Video is made with a still image, recording was audio only.

Spatial Practice - Acquisition 2

Received these higher quality induction coil transducers in the mail from eBay. 

Fantastic sound, highly receptive.

Spatial Practice - VHS + TV Test

Both VCR's failed initial test, TV powers on, appears not to display signal.

Will have to reassess project based on available materials.

Spatial Practice - Acquisition

Acquired 2 VHS players and a CRT Television from hard rubbish and donation. 

Also discovered the stand which is perfectly sized and may serve to house the installation.

Testing these soon.