Chromata Technical Specifications

Overview

Described by some viewers as “an abstract painting that continuously repaints itself,” Chromata is an interactive, generative work that algorithmically creates a continuously-changing, mesmerizing field of light.

Presented here is an installation-sized version of a piece for which there is a fully operational 20 inch square prototype. The software is already complete and the piece is based on an existing robust software code base that has been developed by the artist over the last four years.

Chromata prototype.

 

The above video is also available here:
Chromata prototype video

This proposal will describe in detail the following aspects of the work:

The costing breakdown for this piece is available here:
Chromata cost breakdown

Dimensions and weight

The main part of the Chromata installation consists of two panels and a stand. When mounted on the stand, the overall height is 84 inches (from floor to the top of the panels) the width is 96 inches from side to side, and the base is 36 inches deep.

Chromata on stand, with human for scale.

The separate interactivity podium is a commercially-available tablet stand with approximate dimensions of 12 inches by 49 inches by 16 inches.

The entire installation will weight under 300 lbs.

Physical build

Chromata will consist of two 48 inch by 96 inch panels mounted back-to-back on a stand. When mounted, the stand elevates the panels 36 inches off the floor. The installation is meant to be installed in the middle of a room where viewers may walk around the piece.

The panels will encase an array of computer-controlled LEDs behind a diffuser.

The panels and stand will be primarily constructed from wood, with all wood surfaces painted white.

Chromata installation’s main parts.

Panel construction

Chromata has two panels each of which are identical. Structurally each panel is comprised of a rectangular frame made of 2 x 4s, a 1/2 inch plywood backplane, and borders on all sides of 1/2 inch plywood.

Panel rear view showing frame, backplane, and borders.

The front of each panel consists of a single sheet of 1/4″ ice white acrylic, fastened to the backplane at 10 points on standoffs.

Panel front, with diffuser pulled away revealing LED strips and standoffs. Actual diffuser material appears opaque.

The panels are designed to be removable from the stand for transport. The bottom of each panel sits on a shelf and is secured by L brackets. The top of each panel is attached to the stand with additional hardware.

Stand construction

The stand is constructed from painted 2 x 4s and 4 x 4s.

Stand with panels removed.

To facilitate transport, the stand is designed to come apart into four pieces: left vertical support, right vertical support, top horizontal support, and bottom shelf support. The base feet are permanently attached to the vertical supports. All removable sections are connected to one another with lag bolts and similar hardware.

The power supply and small computer will be attached to the back of one of the panels.

Electronics

Each Chromata panel holds 2,485 RGB LEDs arranged in a 71 x 35 array, with the LEDs spaced 1.31 inches apart in both dimensions. These LEDs are, for technical reasons, separated into two halves, one with 17 rows and one with 18 rows, with the control computer located centrally.

The LEDs are 5050 (5mm square) surface-mount RGB LEDs mounted on flexible strips, 30 LEDs per meter. The LEDs are of type APA102C, which is a compact die-in-LED design. The LEDs feature 5 bits of brightness control which is employed to reduce brightness. By running the LEDs at about 1/4 power the piece will emit a comfortable, room-filling amount of light but will be mellow enough to allow a contemplative viewer to stare at the piece without discomfort.

Chromata uses APA102C LEDs on flexible strips.

The control computer is a Raspberry Pi Model 3 B+ running a custom C++ program authored by the artist (who is a professional software engineer). The code driving Chromata is complete and tested. This proposal includes a video demonstration of the software running on a 20 inch square prototype, including tablet interactivity.

Raspberry Pi 3 Model B+.

Both the computer and the LEDs are run off a Mean Well model UHP-500-5 5V, 80A solid-state, fanless power supply. As planned the piece will never draw more than 40A from this supply, well under its rated current.

Power supply.

Interactivity

Chromata is viewer-interactive employing a custom tablet computer application that communicates wirelessly (over Bluetooth) with the Raspberry Pi control computer on the backplane of the installation.

The interaction tablet will be mounted on a commercially-available tablet kiosk stand similar to the one pictured below.

An example tablet stand.

As of this writing, the viewer can control the speed, color, and symmetry of the panels using the tablet application. An early version of the application is pictured here.

An early interactivity interface for Chromata.

The above interaction interface is written and operational, and can be considered the minimum level of guaranteed interactivity. However, the artist reserves the right to improve the interaction experience between now and the conference.

Other considerations

Power requirements

Chromata requires 120V AC power via a standard three-prong USA outlet. It is projected to draw less than 5A at 120VAC, which is 600W. Additionally the tablet kiosk will require negligible AC power.

Duty cycle

Chromata‘s software is mature and robust, and runs reliably for weeks without maintenance of any kind. If so desired, the piece can be powered off at night. The artist will be on hand should any issues arise.

Lighting

While Chromata generates quite a bit of light, it is meant to be viewed in a dark or dimly-lit room. The piece itself will constantly light the room so no further lighting is necessary.

Benches

Chromata is a relatively slow-moving, contemplative piece that very much rewards lengthy immersion by viewers. It would be optimal if the venue could provide two benches, one for each side of the piece.