For this studio the task at hand was to create an installation for Pittsburgh which drew from what made the city special, and which created a responsive environment for users which provided some value beyond just being pretty.
Pittsburgh steps
The Pittsburgh steps are an artifact of industry, a remnant of a social structure and way of life that has almost entirely gone away. They work as part of a larger navigational infrastructure which hopelessly battles the topography in an attempt to help residents move about the hills and valleys.
Originally built to move workers between their homes on the hills to the mills on the rivers, the steps were part of daily life. Today these steps are in various states of disrepair and often don't particularly lead anywhere. That said they are still in use today, a great many of them (344) are even legal streets with residential addresses on them.
For these reasons the steps seemed like an excellent stage to build on for our installation but to be sure we'd need to understand the steps a little better.
Site selection and surveying
There are 739 surviving runs of steps in Pittsburgh. That's a big number and it meant that if we were going to choose a site we'd need to get out into the city and understand the neighborhoods, materials, views, and environments that we'd be working with. We began by mapping the stairs in Pittsburgh and visiting the neighborhoods in which the most stairs remain.
We walked the steps, photographing them and documenting their surroundings. We were struck by the way these urban relics became a sort of scaffolding over time, a framework on top of which the neighborhoods grew. The steps are sandwiched between new buildings and old burnt out foundations. These traces, ruins and relics show a legible history of the neighborhood and city at large. Mapping these relationships became a major focus of our work. These mapping exercises supported our understanding of the steps as part of a larger navigational system in the city. Here you see the steps raised out of this grid and shaded in blue. On the left you see the grid on its own, on the right you see the grid with the addition of buildings.
Because of the community's interest in preserving, maintaining, and using the steps in their neighborhood, we decided to narrow our site selection to the steps in Polish Hill. In addition to the residents commitment to their steps we found the steps themselves to be quite compelling and varied. We found a number of different typologies of stair as well as a great variety of lengths both of individual runs and of longer paths created by multiple segments of stair. These findings can bee observed in this timelapse created while moving through one of the longest paths of stairs in the city.
Materiality
Understanding the materiality of all the potential steps we might work with in the neighborhood was critical. We began diagraming the construction of the steps. These studies showed that there were three main typologies of stairs in the area, two constructed of concrete and steel tube and one other built from wood. Each of these offered different opportunities for interaction via projection. Each type of stair also created different sounds and vibrations offering different qualities of experience.
Sensing
When thinking about interactions we might be able to create, we tried to think about how people use steps. We realized that pace and frequency were variables which we might be able to sense as a means of identifying how a person was engaging with the stairs. This might enable us to create dynamic interactions on the steps. Additional work was then done to identify what sensors might by employed to capture different types of interactions based on these variables.
We grouped various interactions based on their level of activity and engagement with different elements of the stair. We created four categories for these interaction which allowed us to think meaningfully about how we might sense users presence in these various conditions. We explored a variety of sensors including ultra-sonic proximity sensors, pressure sensors, motion sensors, IR distance sensors, and conductivity sensors. Each one offered different opportunities to sense different categories of interaction.
To sense these interactions reliably we developed custom piezo based sensors to get clear reliable data from our steps. The process involved adding an additional ground and creating a faraday cage around each piezo. This process is shown in the image above.
Pace, frequency, and interaction
We realized that if we could sense the pace (time between steps) and frequency (pressure of each strike) we could understand the movement of an individual in a meaningful way, perhaps even in a way which would allow us to capture their presence and redeploy it into that space. We came up with the idea of creating an acoustic and visual experience in which a user's presence was sensed through piezo sensors and projected back into the space around them, creating a sort of sticky shadow which followed them and created a trace of their presence on the steps. This interaction was explored through the diagrams below.
These diagrams are the result of a length exploration of various graphic styles and interaction concepts. Here we explore the use of solids, voids, or lines as tools to describe the presence of an individual and toy with what happens when multiple users engage the steps at the same time.
The diagram above shows a break down of how the previously illustrated interactions might works. A person walking is shown in white. The curve which trails behind them describes the intensity of their steps. The blue figures above are an abstracted projection (their sticky shadow) which traces their presence. The lines above this shadow represent an oscilloscope style representation of how the shadows fade as the person moves away from them.
Moving out into the world
We built models to visualize these interactions in the situation.
With our interaction designed, sensors developed and several potential sites selected we used photoshop to project our interaction into the landscape as a means of evaluating which site we might select to continue on with.
Pivot
After our mid-semester review we took a step back. We thought very hard about the conflict we struggled with between creating a compelling & legible installation and connecting our experience with the history and research of the Pittsburgh steps in a meaningful way. We spent a considerable amount of time revisiting the steps, trying to distill down the magic of the steps, the element which captivated us. We came to two conclusions:
The accumulation of these steps in the landscape was key to understanding them as part of a layered and legible history of Pittsburgh. The geography of the city could be read through the mapping of these steps.
The physicality of the steps, their relentless, the sensation of trudging up them, or rushing down them was an essential element of this local oddity.
Our goals for the remainder of the semester became refocused. We thought about how we might be able to emphasize these aspects of the stairs through out installation. We became focused on sound as the key element of our interaction and decided to locate our installation in the college of fine arts. We also began exploring 3D scanning and other tools as a means of capturing the stairs and locating them in the landscape. These two tracks would consume the rest of our energy as we hurried towards the end of the semester.
Scanning and mapping
The idea of creating a 3 dimensional visualization of the steps was, for us, a way of contextualizing our experience. Providing users anywhere with an opportunity to see and understand the steps individually or as a system. To do this we utilized a number of different types of scanners and meshing tools, creating our own hybrid work flows and even cowriting a virtual reality viewer app to see the steps through. Our app would allow anyone to, through their phone, look at a specially designed map of Pittsburgh and see our scans floating in their proper locations above the map.
Our initial tests showed the potential (high resolution and quality image mapping) and limits (gaps and voids resulted from the fact that scanning techniques are largely designed for either an object or environment and stairs hover between the two categories).
We hoped our work could be the beginning of a sort of collaborative repository which might provide for communities, whose support of and activism surrounding the steps demonstrated a high level of interest, a vehicle for tracking, maintaining, and enjoying the steps.
Church Stair by lwulfman on Sketchfab
Acoustic environments
We thought at first of creating a sense of accumulation through layering sounds triggered by a user as they move through the space. Using Free Sound we began creating geotagged recordings of foot steps on each of the steps in Polish Hill. These recordings, when triggered one by one as the user moved down the steps, would give a sense of an accumulation of people walking down the steps with the user. This concept required the use of new sensors and the development of a sensor enabled speaker which could be triggered in this way.
Our first iteration of this sensor enabled speaker (diagrammed below) utilized a simple photoresistor. As users walked by the photocell they would cast a shadow on the sensor triggering the sounds.
These would be triggered as illustrated below.
While cheap and effective, this sensor required particular base conditions to work (a certain quality of light). It also had a large trigger range, meaning we were not able to precisely locate users on the steps to create a trigger event. This made it less than ideal for our purposes so we moved on to a new sensor technology.
IR distance sensors created a much more precise trigger tripwire condition. Precise and effective in all lighting conditions. These sensors seemed ideal until we began tallying the cost of all of our components. In this iteration we also began to explore the idea of mashing two audio tracks together into a single R L channel. This would allow us to further reduce our costs by allowing us to trigger multiple sounds without using additional expensive sensor/ controller hardware. To further assist in separating the sounds produced from the right and left tracks, we canted the speakers away from each other allowing the sounds to expand and reflect in opposite directions.
In the third iteration of these units, we developed a way of moving all controller hardware out of the speaker unit. This allowed us to separate the speakers into their own housings which could be moved as far apart as the length of connecting cables would allow. We also moved to an ultrasonic distance sensor which was nearly as effective as the IR distance sensor in creating precise trigger thresholds at less than a quarter of the price. At this price we were able to introduce a second distance sensor in each set of speakers (one for each individual speaker). This gave us the ability to interpret the direction of movement on the steps.
In tests we found that the sounds of steps, while powerful, did not create the spatial affect we had hopped. These sounds also came off a bit cheesy and perhaps heavy handed.
In the third iteration of these units, we developed a way of moving all controller hardware out of the speaker unit. This allowed us to separate the speakers into their own housings which could be moved as far apart as the length of connecting cables would allow. We also moved to an ultrasonic distance sensor which was nearly as effective as the IR distance sensor in creating precise trigger thresholds at less than a quarter of the price. At this price we were able to introduce a second distance sensor in each set of speakers (one for each individual speaker). This gave us the ability to interpret the direction of movement on the steps.
With this new sense-able parameter we began to rethink the sounds we might play through these speakers. Shepard tones are an auditory illusion in which a pitch seems to rise or fall perpetually. By triggering a descending pitch as one moved up the steps and an ascending pitch as one moved down we hoped to be able to exaggerate the physical sensation of trudging up or zipping down the steps.
In the forth and final version of our sensing speakers we moved the speaker driver board into the speaker unit. This was largely driven by constraints produced by the selection of a new type of speaker we employed (a type we could purchase in quantity). We also made a series of small aesthetic changes.
This became the iteration we deployed in our final installation. We spent the rest of the semester tuning the sensing and playback code to be as robust as possible. The final installation looked something like this:
