By Barbara Robertson

June 28, 2023

Reading Time:
9 Minutes

Many people imagine holograms look like images of characters beamed into films like Star Wars or Star Trek, or as Tupac and Lawrence Kardashian, Kim’s father, resurrected as holographic light and seen online.

But, the first step toward holograms more than 400 years ago by the Italian scientist Giambattista della Porta, was a holographic illusion using objects in a room.

Della Porta, the inventor of the camera obscura, called the illusion “How we may see in a Chamber things that are not” in his 1589 work Magia Naturalis. He writes: “Let there be a chamber wherein no other light comes, unless by the door or window where the spectator looks in. Let the whole window or part of it be of glass, as we use to do to keep out the cold. But let one part be polished, that there may be a Looking-glass on both sides, whence the spectator must look in. For the rest do nothing. Let pictures be set over against this window, marble statues and suchlike. For what is without will seem to be within, and what is behind the spectator's back, he will think to be in the middle of the house, as far from the glass inward, as they stand from it outwardly, and clearly and certainly, that he will think he sees nothing but truth.”

Giambattista della Porta

Today, we know the illusion as “Pepper’s Ghost” after the scientist John Henry Pepper who popularized it in 19th-century theater productions. (See “The History of Pepper’s Ghost” by Trevor Hogg in the April 7, 2022 edition of HoloWire.)

Although Pepper’s Ghost has not veered far from its theater origins, holography, that is, actual “wave front reconstruction,” has found more serious applications in architecture. Invented in 1948 by Dennis Gabor, “wavefront reconstruction” holography was rewarded with a Nobel Prize in 1971.

In the paper “Holography: Art and Science of light in Architecture,” Sam C. M. Hui of the Technological and Higher Education Institute of Hong Kong and Dr. H.F.O. Müller of Green Building R&D (Düsseldorf, Germany) and head of the department of sustainable architecture at the University of Dortmund, writes: “Holography has become interesting for architecture not only because of its paradoxical representation of the 3-D space but also for its physical characteristics, dispersion and diffraction of light. Holographic films, known as 'holographic optical elements' (HOEs), can be laminated between two glass panes and used for various applications in architectural design. Holography also opens up new possibilities in architectural and interior designs by acting as an information guide in public spaces and creating three-dimensional images for architectural presentation.

Holographic Optical Elements 

The article appeared in “Architectural Science Review,” September 2001, and at that time Dr. Müeller was creating products that used HOEs for daylighting and shading buildings.

“When I was teaching architecture at the Polytechnic in Cologne, I was interested in daylighting,” Dr. Müeller says. “I met a colleague there, a physicist, who is an expert in holography. He thought it might be possible to use holograms for daylighting.”

The colleague, Prof. Joerg Gutjahr, created a model of an office room and installed a hologram that redirected daylight to a ceiling and deep into a room.

“Not a hologram for visualizing three-dimensionally, ”Dr. Müeller explains. “A kind of holographic optical element (HOE), an optical element generated by holography; a prism that he could generate by holography.”

University of Breman Holo-Lux® Products. Image courtesy Dr,-ing. Helmut FO Müeller

Grants for more research led them to create HOEs on films two meters wide with arbitrary lengths. To protect the film against humidity, dirt, and physical impacts, they laminated the film between two glass planes. The glass could then be installed on building facades and within buildings.

Dr. Helmut F.O. Müller

The HOEs had three applications and were installed in various locations, but each had quirky drawbacks. “Holo-Lux” could indeed “daylight” interiors, but in doing so, it created rainbow colors at first. (“White light holograms” could solve that.) Artists became interested in the ability to exactly define colors picture element by picture element, but the “Holo-Color” colors in resulting designs shifted depending on the angle of view. And, although the HOEs in “Holo-Volt” worked perfectly for shading, and could generate solar power when combined with photovoltaics, they needed to track the sun.

“They worked perfectly for about 10 degrees, but we needed 60 or 70 degrees,” Müeller says. “So, they always had to be moved according to the solar position.”

Ultimately, the technology proved too expensive for practical applications, and Müeller is now using micro-optical building components.

“The new structures work for all angles and there’s no dispersion of rainbow colors,” he says. “That’s an advantage for daylighting. But, if I look around in architecture, I see spectral colors without specific designs used by architects like Jean Nouvel, for example. And, I think 3D holograms could be interesting for people to use in glass facades. Instead of a showroom with a large window, they could have a holographic screen and show things in three dimensions. The 3D visualization of architectural design in combination with BIM will be a new task for holography. It will be a helpful tool for architects as well as clients to achieve improved designs and better architecture. Architects could also shape rooms or whole buildings by holograms.  3D images could generate different rooms and atmospheres, changing shape, structure, color, and light by time. That could be possible.”

Hologram-like Illusion

A hologram-like installation at ARTECHOUSE for its New York City and Washington, DC locations demonstrates that possibility. In both locations, visitors to the digital and experimental art installations would typically hang out in a bar where XR (app powered) cocktails and mocktails curated after the latest exhibits were served. Then the pandemic hit.

ATRECHOUSE Nighthawks "hologram like" bar installation. Image courtesy ARTECHOUSE.

“Our exhibitions could run, but during part of 2020, indoor dining was restricted,” says marketing director Josh Feldman. So, working with the Austin-based Noiland Collective, ARTECHOUSE used a “hologram-like” installation of a bar. The installation brought to life Edward Hopper’s 1942 Nighthawks painting of a diner’s interior viewed through a large window. The painting was appropriate because like most of 2020, the early part of the 1940s was a time filled with anxiety and concern. Projection techniques created the 3D hologram effect.

“We were able to use the framework of the bar and reverse project onto it,” Feldman says. “Although there was no bar open, visitors could experience the installation and reflect on a work designed to combine past and present, and at times see themselves reflected through shadows.”

The pandemic in 2020 and 2021 also opened an opportunity for researchers in Milan to look at new ways for the public to visit popular Monza Park. Within the park a typical Sunday crowd of 90,000 moves through the seven square meters of lawns and woods, 13 farmhouses, three historic villas, and 13 meters of fencing. But the pandemic meant reducing and controlling the movements of the public.

Holographic Cultural Heritage

To convey the open space and historical monuments to visitors, the researchers looked at reproducing them in virtual reality and with “holograms.” The goal was to install a VR experience in a seven-meter diameter 360-degree theater and use Axiom’s “Holographic Table,” which lets people wearing glasses view stereoscopic hologram-like 3D buildings and landscapes in a dark room.  

C. Bolognesi, M,  Vespasiani, and Y.  Zhang from the Department of Architecture, Built Environment and Construction engineering at Politecnico di Milano, describe the process they developed to accurately reproduce Monza Park heritage buildings and landscapes in a June, 2022 paper. They published the paper in The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences.

After testing various methods, they settled on using Orthophotos from Metashape as maps, importing the maps through the OBJ file format, UV mapping the materials onto surfaces in Blender, and then exporting FBX files to Unreal Engine 5. The work is ongoing.

“It’s a balancing act between model accuracy, hardware system capability, and software interoperability,” says Cecilia Bolognesi, who leads the Labor A Virtual and Physical modeling lab at Politecnico in Milan.

Schutzenberger Beer Palace, Strasbourg, France -Image courtesy The Ateliers Jean Nouvel

“We have made a lot of progress since that paper and are very happy with the visualization of all the architecture, the accuracy, and the green placement,” she says. “The main theme now is to visualize a lot of textured models in a vast environment with plants and fields without losing accuracy. The size of the display in ‘holographic’ mode while maintaining accuracy is a real challenge.”

The central issue is the accurate texturing of models.

“In our country, there is no meaning for building without precise materials,” she explains. “Cultural heritage is everywhere. It’s very different from renderings for gaming. It’s about applying real textures in contexts where a crack makes a difference. It’s a very interesting field.”

Axiom’s “Hologram Like Table” was also recently used by Prime Minister Modi of India to unveil models for a planned airport, and it has found a home in military, schools, and mining applications. Founded in 2010 and originally called Euclideon, the Australian company boasts having customers in the UK, Europe, the Middle East, Australia, and the US forits table and its “Hologram Wall.”

Someday, the promise of the stereoscopic Hologram Table and Wall will be realized outside dark rooms and seen by multiple people who don’t need to wear special glasses.

Future Architecture

 “Overcoming the frustration of paper or even digital paper spread out only on the x and y axes will be a great opportunity for those of us who have to show spaces only imagined to others, ”Bolognesi says. 

Architect Tom Allen agrees. “I was in the generation where we started with pencil and paper, moved to ink on mylar, moved then to AutoCad and to Sketchup,” he says. “These tools help you design, but they still don’t give you the ability to walk around a full-size model, raise a ceiling, raise the window, and change the flooring in real time. You can do a virtual walk through on a screen, but it isn’t the same thing.”

Allen had imagined creating tools in VR to do collaborative realtime design, even remotely, but he was too early-- “Cell phones couldn’t even send video yet,” he says. So, he moved on to other inventions and created a company, iBEAM Construction Cameras for realtime video streaming and time lapse videos of job sites.

“Design is a process of visualization,”he says. “Holography will play an enormous role in helping the public, the client, and the design team make realistic assessments of a proposed project. It will be much better than relying on a drawing and an architect’s arm wave.”

Someday, an architect might wave at a hologram of a life-sized kitchen counter rather than drawing the size and height of that counter in the air. And that will be as much fun as watching Star Wars’ Princess Leia’s hologram asking for help from Obi-Wan Kenobi.