Feature

Vivid Imagination

Interactive Light Installation at Vivid Sydney

CREATE NSW

Issue 2, August 2017

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Many minds and hands came together from CREATE UNSW to produce an interactive light installation that responds to the person standing in front of it.

CREATE UNSW is a maker group based at the University of New South Wales (UNSW), Australia. Based on the UNSW campus, in just five years the club has grown to over 2,000 members. This passionate community brings students together, holds workshops for the general public, and is achieving some amazing things. Unlike your average neighbourhood maker club or hacker space, CREATE UNSW is sponsored by the UNSW Faculty of Engineering, and most recently they developed a stunning interactive light display as part of the 2017 VIVID festival in Sydney. Their installation, titled “Crystallise”, reacts to the people moving in front of it by generating a sensational interactive experience. We caught up with CREATE UNSW President Anthony Feizi-Sobbi, to hear all about it.

A few members of CREATE UNSW with Crystallise.
A few members of CREATE UNSW with Crystallise.

How did CREATE get involved with the VIVID Festival?

Since 2014 we’ve presented at the VIVID Ideas speaking forum. There, we’ve talked about lots of things, from the use of drones to presenting an interactive Pac-Man installation. Our first official appearance in the Vivid Light Walk program however, was in 2016, when we presented the Mondrian Cube at Circular Quay. Mondrian Cube was inspired by the works of the 20th century Dutch artist, Piet Mondrian.

Crystallise marks our fourth year of involvement with the festival, and our second year having presented a project as part of the official light walk program.

That’s awesome. We would have totally voted for Pac-Man! What did you create for the 2017 festival?

This year’s project, Crystallise, is an LED mural comprising of multi-coloured triangular and quadrilateral forms. The installation appears to be a mosaic, but encourages viewers to come closer by displaying randomly generated colours and patterns. As they come into close proximity with the mural, sections of the canvas fade, leaving behind only a pair of wings.

Our main inspiration is Colette Miller’s “Angel Wings” murals, which were exhibited as street art in Sydney (Australia), Los Angeles (United States) and many other locations. To Miller, the wings represent our “inner angel” and remind individuals of the pure and good part of the human condition that emerges, even when individuals experience trauma and guilt in their lives. The wings’ embodiment of the human spirit challenges individuals to consider their choices as humanity, and work towards a greater good.

We decided to extend Miller’s artwork to include different spectrums of humanity, and the idea that everyone has secrets or hidden truths. By having different lighting patterns on the artwork, and hiding the pair of wings until observers come close enough to see them, the installation allows people to fulfil their desire to find truths within themselves, and recognise and cherish their individual differences.

How did you go about creating your installation?

Last September, Destination NSW invited artists to tender ideas for artworks, so we first selected a main idea and then drafted our submission. Before and during the submission process, we designed the basic structure, additional features and electronics. Final acceptance into the festival required an interview with festival curators, back in November/December. Following our acceptance, we developed a prototype during Australia’s summer break (December 2016 to February 2017), to gain experience in how to best build the main artwork.

We produced a detailed design of the final structure using CAD and parametric modelling. We used Rhino 3D plus the Grasshopper plug-in to produce graphics for mosaic and wing patterns. LEDs are programmed serially and controlled with a Teensy microcontroller. The procedure for physical construction of the installation was as follows, with some components being manufactured concurrently:

  • The structural frame, which is divided into two halves, was machined, painted and assembled by hand.
  • Protective plywood covers for the side and back of the installation, an elevated platform for maintenance, supports for the installation, and wall anchors were cut and painted by hand.
  • Corflute spacer, structural plywood for the backing, and front decorative panels were all machined by either a laser cutter or CNC, and we used Grasshopper to generate the patterns for the parts.
  • The frame and backing plywood were attached. We drilled holes to install spacers for the attachment of the diffuser/front panel. Both halves of the frame were joined to the floor with additional bracing.
  • Corflute was installed to prevent spillover of light between sections, and we used laser-cut mounts to hold the LEDs in place.
  • High impact polystyrene was used as a diffuser. Since it cannot be laser-cut it was cut by hand, then attached to the front plywood covers using liquid nails.
  • Front plywood panels were progressively installed onto the main structure, and secured with screws. We used black silicone to seal any large gaps.
  • Infrared sensors were inserted into extra large holes, which were drilled into the panels in the middle of the structure.
  • When transporting, the installation was taken apart into halves, and reassembled onsite with the supporting platform. It was then anchored to a ledge behind the wall.
  • Protective covers were installed.

Wow, that’s quite a lot to coordinate; but you clearly pulled it off. Tell us a bit about how the installation works?

The wings and custom lighting patterns are generated in Grasshopper, and are programmed into the installation using Arduino code, which was written by our software team for a Teensy controller. The software indexes each region of LEDs, which represent the triangular and quadrilateral shapes on the mosaic, using graphs to determine a particular region’s distance from a selected centre region. It then turns regions on or off, according to a supplied algorithm. Distance is provided for the programmer’s reference, and can be used to design and implement patterns such as light radiating from a centre point, or striated lines travelling in several directions across the mosaic.

Infrared sensors installed vertically in the middle of the installation, detect if there is a person standing in front of it, at which point the remaining LEDs fade out and reveal the wing patterns. Depending on the person’s height, different sensors will be triggered and certain combinations of triggered sensors will result in the base of the wings appearing higher or lower. The installation returns to normal programming once the person leaves the centre of the installation.

We installed an RFID card reader towards the final stages of construction, so that team members could trigger custom patterns for personal occasions. For example, one person even used the wall to propose to his partner!

We absolutely love how it’s customised to the visitor, so everyone has a slightly different experience! Obviously much of your design process would have focused on materials, given it’s a large physical installation. What factors were considered when selecting hardware?

We took into account the fact the installation will be outdoors and near a wharf, so we needed to make the installation and its interactive components robust and easy to maintain. We chose all of our components to be rated for outdoor weather (IP64 and above), from power supplies to LED modules right down to the sensors that were used.

The electronic hardware for light control was kept minimal as well - normally for LED displays of this scale, people would be looking at breaking out a laptop or some mini-computer to do video processing in order to control the lights; but due to the location we were in, we had to use something that could be replaced cheaply and easily.

Create UNSW team at work
Wiring was no easy task.
Working on the project
Testing a few of the 1550 LEDs installed.

The LED modules we used were IP68 UCS1903 lights, which can be powered by common 12V power supplies and draw a maximum of around 0.9W per module. There are approximately 1550 LED modules used for the whole installation, so its maximum power consumption is around 1.6kW. To cater for the maximum power consumption, we used four 400W outdoor power supplies.

The microcontroller we chose to use was a Teensy 3.5 - it had more I/O ports than we needed, a faster clock speed over the 3.2, and 5V-tolerant digital pins, which we wanted for our application. We decided to manually map out all the locations of the LED modules, and then group them into eight long strings. This enabled it to be used in conjunction with the OctoWS2811 shield. While it is technically possible to control the UCS1903 LED modules - using the 3.3V output from the Teensy I/O pins directly - it’s typically recommended to use 5V logic for most of the addressable LEDs on the market, as this prevents issues such as signal deterioration. The OctoWS2811 shield does the level shifting on the I/O pins from 3.3V to 5V nicely, and it comes with ethernet ports for the signal and ground pins of the LED modules, which helps reduce electrical noise. Its usability and robustness also makes it very easy to use and replace.

In terms of sensors, we tested a variety before settling on our final choice, which was the E18-D80NK. We wanted something that can give a binary reading, to save on additional processing times (as opposed to using a sensor that requires analog input, or a fancy timing library). We also chose this sensor as it only uses three wires, which makes the electronic installation easier.

1.6kW - wow! It helps give scale to this massive installation though! The PJRC Teensy sounds like it suited the installation well. Obviously you didn’t tackle this whole thing by yourself; how many people worked on the project?

We had 18 team members, divided into three subgroups and they were responsible for structural design, electrical design and software programming. Construction was a whole team effort, mostly led by the structural design group. Team members were free to transfer between groups, or help others depending on their expertise and prior experience.

Four 400W power supplies provide the 1.6kW required.
Four 400W power supplies provide the 1.6kW required.
Testing during final stages of construction.
Testing during final stages of construction.

That’s a great way to help people gain experience across different parts of the build. What was the most challenging aspect of the project?

For most team members, it was the balance of project work with jobs, university assignments and other commitments. For the team leader, it was managing the different schedules and logistics, as it was her first time leading a huge team. The project was unusually construction-heavy, and we had several design issues during the build. While most of the issues were solved with improvisation, much of the work was completed at the last minute.

There’s nothing like a deadline to get things moving! What was the best part of the overall installation?

Observing how people interacted with the installation. Usually, it takes some experimentation for them to stand in the right position to trigger the wings, but once the wings appeared, it was always rewarding to see their amazement in the function and aesthetic of the artwork.

There’s nothing like seeing people enjoying the interaction with something you’ve worked hard on! The proverbial “version 2.0” often conjures up new ideas and possibilities. Given the same brief again, what would you change?

  1. Add sensors on each side, and program the wings to shift laterally, in addition to upwards and downwards. We did not consider this option due to the technical complexities involved, but given more resources, it would be a great addition to Crystallise’s functionalty.
  2. Design a light source to illuminate the viewer’s face for photography purposes. Currently, photography of people standing in front of the installation requires diffused light that is pointed away from the subject, so as to provide enough light to make the subject’s face visible. However, we have found creative ways of photographing people in front of the installation, such as excluding background light and making the subject appear as a silhouette in front of the artwork.

The addition of lateral shift would possibly make it behave almost like a full-sized human heat map! That would be amazing to watch, but would definitely require more processing. We'll be keenly watching what you all get up to next!

Create UNSW team at work

About CREATE:

CREATE is a student-run club at the University of NSW that runs, collaborates and supports practical projects to help students learn skills in engineering, invention, and design. They also run and provide workshops for beginners on electronics, programming, soldering, prototyping and 3D modelling, and they also sell electronic components on campus.

Projects run by the club include UAV development, UGV development, machine vision workshops, and competitions for autonomous cars and various personal “gadgets”. CREATE was involved in the 2016 UAV Challenge: Medical Express, and QUT Droid Racing Competition (they came first place in DRC 2016 and 2017).

Most CREATE members are current UNSW students studying engineering, built environment, or art and design, but absolutely anyone can join; the club is open to students from all faculties, and members of the wider community are welcome to partake in the activities as well.

One of the coolest things about CREATE is that it provides members the opportunity to become involved in different aspects of the maker community, and it enables students to develop valuable technical and interpersonal skills. For students it also gives them real-life opportunities to apply in practice, what they might be learning about in class.

CREATE caters to university students and community members of all skill levels, from absolute newbies to those with advanced knowledge. Their workshops provide fundamental programming and electronics knowledge which is an ideal starting point for new makers who want to participate in their projects. If you can’t make it to the workshops, they are usually live-streamed on YouTube.

For details about events, workshops and other information such as Q&A and project sharing, visit: CREATE UNSW

IMAGE CREDIT: Grant Turner

VIVID PROJECT CREDITS:

Lead Artists: Yunzhen Zhang, Christopher Ho, Alison Zhang, Randy Tjang, Guoyu Chu, William Weng

Collaborators: Jabez Wilson, Junji Moey, Alexander Lam, Peiju Li, Emily Chan, Kevin Yu, Daniel Castillo, Jason Phu, Jonathan Hribar, Anthony Feizi-Sobbi, Jonathan Timmerman, Yuen Chan, Daniel Wong