Do not miss this and save in your calendar:



Plotter Drawings and Generative Art

83-year-old Hans Dehlinger has lived a life with many chapters. Early on, there was the chapter when Dehlinger studied under German philosopher and logician Max Bense and alongside Frieder Nake, today one of the most well-known pioneers of computer art. Then, Dehlinger entered the Berkeley chapter, where he studied and later worked as an environmental planner and architect, before entering a chapter experimenting with plotter drawings and generative art. With a broad approach to art and an ever-curious mind, Dehlinger combined the previous chapters and knowledge and has become a pioneer of generative art.

With a focus on algorithmically generated line drawings, Dehlinger bases his generative artworks on computer code executed on pen plotters, forming delicate structures, dense textures, or even evoking an unsharp impression from sharp lines.

In conversation with Anika Meier, Hans Dehlinger discusses his career and early computer art, the past and present of generative art and the connection between science and art.

Portrait of Hans Dehlinger: Courtesy the Artist.

Anika Meier: Mr. Dehlinger, Max Bense was your professor, Frieder Nake was one of your fellow students at the time. So you witnessed the early stages of generative art. What did you experience with Max Bense?

Hans Dehlinger: I studied architecture in Stuttgart. Max Bense lectured in what was then known as the "Studium Generale." I don't believe something like that exists anymore. People from all kinds of faculties gathered there. It was really exciting. There were no exams like in statics, building law, design, and so on. It was about questions concerning the art form of concrete poetry, which was fashionable at the time, about the types of language that might be used there, and about the more general question of when something is art. When does something stop being art?

Bense's answer, very briefly: Avoid the term "art" altogether. The term art is far too loaded, Bense said. Therefore, introduce the term "aesthetic event."

He once came in with a little metal art figure. "What is this?" Bense questioned, holding up the art figure. The entire assembly exclaimed, "Art!" Then he placed the figure in a vat containing something, acid maybe. Then the lecture began. Bense eventually took the figure out of the vat again and asked, "What is this?" "Art!" said everyone once more. The lesson then continued. Bense eventually took the figure out of the vat again, and it had already begun to dissolve. "Art!" yelled fewer and fewer people. At some point, the voices fell silent altogether.

It is undoubtedly a lot easier to define when something is no longer art than when it is. That was Bense's point: How can one define art? How is that calculated?

These lectures were extraordinarily focused and covered things that were absolutely foreign to me. The group of listeners was also interesting, because they came from all faculties of the university. There were often heated discussions.

As a freshman, exciting things were happening around Bense. One day, I noticed Frieder Nake observing the construction of a drawing on his plotter in the Institute for Numerical Mathematics. So as the plotter was running, and as I stood back, Nake called out to me, "Come here and have a look! It's fairly straightforward. I'll show you how to do it."

That really scared the heck out of me. I thought that if I went there and let myself be drawn into this, my architectural studies would be lost. I couldn't imagine that at the time. There were personal reasons for that. My father was very ill and I had to see that I took care of my studies.

AM: So, back then, you and your fellow students debated a lot about new developments and kept a careful eye on them. Herbert W. Franke, the pioneer of early computer art, was someone you looked up to. What captivated and moved you back then?

HD: It was a very rebellious generation of students back then. Discussions about authoritarian structures were in full swing. This different way of looking at art played a major role in Max Bense's work.

Herbert W. Franke had – in my understanding at that time – a completely revolutionary approach to create his "aesthetic events". His thoughts were related to what Frieder Nake pursued: The design of a generative principle comes before the generation of a result. That blew me away at the time. There was just this fascination that something can be generated generatively, which can then represent an aesthetic event. I consciously perceived that as something extraordinary. How something like that comes into being often played a role in Max Bense's work – the question of how these things come into being, in what way they can be triggered.

ausblob_034, 2006.

AM: And how did you come across art? You began working with programming languages and computers in Stuttgart in 1966. Did you start creating art immediately?

HD: In a very figurative sense, yes. I was interested in architecture. There, too, we had discussions. We were convinced that computers would make things possible that were previously unthinkable.

In the subject of design, there were so-called impromptu designs. You had a few days to complete them. Then you had to present the results, which were then publicly exhibited, publicly discussed, and immediately evaluated. My best friend and I decided at the time to participate in such an impromptu design. The theme was to design a café for beachgoers in a narrow ravine on the beach overlooking the sea. I then developed a computer program that pulled together four or five terms in all possible combinations. The idea was that if you draw up a list of expressions and then generate all the possible combinations with the computer and list each of those combinations in a line as text, then each of those lines represents a "semantic tangle." If one reads such a line, then a picture arises in the head. In a very rudimentary way, one then "sees" the café in the ravine.

I printed out a list of about 2400 such semantic tangles and hung it on the wall. That was – together with a small model where such a "tangle" hung in the gorge – my design. My friend had another idea: to plank the skeleton of an old shipwreck so that it would hang in the gorge as a café.

We fell through with both of these designs. In my case, a long discussion ensued. There were between 50 and 100 people, including several professors. But there was no doubt about the fact that the design was not considered acceptable. In the end, though, one of my professors, someone I hold in very high regard, said, "Who knows, maybe Dehlinger is right after all."

That sentence stuck with me. And that was important to me: that a teacher I respect thought maybe I was on to something.

AM: Was that the first generative design for you?

HD: Yes, and I think it was the very first time that a computer was used as a determining element in a design, so to speak, at the Faculty of Architecture in Stuttgart. The fact that I learned programming at all was something that was not required anywhere. That was purely my interest.

But it was no problem at all within the university to attend such a lecture. The professor who taught the programming language Algol 68 was the same professor with whom Frieder Nake did his doctorate. I must say, however, that I dropped out after a third of that lecture. My program was simple combinatorics, I could do that already at that time.

AM: You first completed an apprenticeship as a carpenter and then your high school diploma via the secondary educational path.

HD: That's right. My background is one reason why these subjects fascinated me so much – because they were absolutely foreign to me. The work environment of the carpentry, then the technical high school at an insane pace, and then the admission to the architecture department and the start of my studies.

My first walk into the university building is still fresh in my mind. It was the new structure for the architects and engineers. We were the first semester in that building. I had goosebumps as I walked through the first-floor door: now you're entering the university, I thought to myself. That was a memorable occasion. My enthusiasm wore off after exactly four semesters. Then it was the opposite: I was completely convinced that everything had to be changed.

MSQ_2,8,11,13|15,9,6,4|14,12,7,1|3,5,10,16|, 2010.

AM: You studied in Stuttgart and Berkeley and worked as a project manager on the Olympic Village design team in Munich. Your educational background is in architecture. When did you initially refer to yourself as an artist?

HD: Actually, never at all. I'm an architect with heart and soul. I was also proud to be able to do this study of architecture. Frank Lloyd Wright called architecture "the mother of the arts." What I did were simply things that I subsumed under that term. I didn't care if other people called it art or not.

I was already interested in theoretical topics in architecture at the time, such as design theory. There were publications about it in professional journals. Two of those educators in the field taught at Berkeley. So I decided to try to get there. Then I earned a scholarship, which I consider a huge blessing. But that's another story.

The fellowship ran for three quarters of a year, as UC Berkeley was on the quarter system at the time. So when it ended, I went to my teacher to say goodbye. And then he offered me a job. The reason, as I would see it today, was that I was very involved with computers at Berkeley. And there, again, I was fortunate to have a fantastic teacher, Laura Gold, who for the first time at Berkeley taught Computers for the Humanities, which is computer applications for faculties that are not primarily mathematically oriented. Snobol 4 was the name of this language, which I learned thoroughly and worked with a lot and also drew with.

AM: Frieder Nake started working with plotters back then during his studies. You already stated that you chose against it despite your fascination, despite the fact that you had the feeling: Something is going on here! Why?

HD: Plotters were still very expensive back then. There was also no easy access to plotters; even at Berkeley, the plotters at the computer center were not that easily accessible. So I focused on computers and programming languages, and I also programmed with natural language at first.

AM: When did you finally decide to try your first experiments with the plotter?

HD: That was in Kassel. I offered a seminar there for students of textile design. They are well trained in algorithmic procedures. Punch cards and everything related to them come from weaving.

So I arrived in Kassel and wanted to do this computer course with the students. But we didn't have a computer at the art school. The electrical engineering department had a lab where one was available for the students. So I went to the engineers and asked if I could use it for one of my courses.

And then we made a little book and also published it; that was the very first thing. Because I didn't have a printer at that time, we also wrote all the text with the plotter. The whole booklet is written and drawn with the plotter. That was great fun. For me, that were the beginnings of generative teaching at the art school.

EVo_xf_01, 2015.

AM: How do you explain what you do to people who have never heard of plotters and generative art?

HD: In terms of generative art, I believe it is fairly straightforward and simple to explain. One is attempting to create a step-by-step manufacturing manual for a project. When it is set in motion, a result is produced. In its design, random processes play a role. Whether one calls the result art or not – I've always been hesitant to call it that. The term "generative art" already contains a limitation.

AM: Since the 1980s, you have exhibited your art internationally.

HD: These exhibitions were almost always linked to academic congresses. The SIGGRAPH – Special Interest Group Graphics – is famous. There were quite a few SIGs in the ACM, the Association for Computing Machinery, but SIGGRAPH was by far the largest, because graphics computing was making such rapid progress. I was a student member of ACM during my time at Berkeley.

When one accepts a professorship, one also has an obligation to represent one’s field in an academic setting. Participation in international conferences is one way to do that. If a paper was accepted, then it was clear that it was professionally interesting, also for the larger community. That was enough for the German Research Foundation to fund such conference visits by professors. That's how I got the funds to make trips to Los Angeles, among other places.

Exhibition View at Hallenbad Ost, Kassel, 2021.

AM: When we last spoke, you mentioned that you got the sensation that something is beginning today and that we are at the beginning of something new. How did you form this opinion?

HD: Language, programming, and art are all being used in emerging AI advances. Language encompasses literature, poetry, and everything else we discuss. Everything we do in terms of artistic activity is art. In terms of programming, everything we do with computers is done through programs. And this is where these AI systems come into play. What they're already doing suggests that they're going to lead breathtakingly quickly to new things that we can't even imagine yet. This approach of AI is happening now – whether we will later like it or not is another question. When we look at ChatGPT in terms of news or just sharing of facts, one really has to say the facts are starting to swim. Everything is conceivable that one could not imagine at all so far.

AM: You are part of a pioneering generation that had to fight much more fights than we do today for the acceptance of digital art. What barriers did you run up against?

HD: A lack of understanding regarding digital developments in general. The faculty from the art department really felt (and expressed that in meetings) that there was no need for computers in art. Mankind doesn't need computers either, they thought; computers are a temporary phenomenon that will disappear at some point. That was really the opinion of these people, who, of course, a few years later were walking around with laptops themselves. It even went so far that a budget that had been earmarked to buy computers was converted into one for cameras at a budget meeting of the art school. The cameras were then purchased; the computers were not. With the result that the cameras were all stolen six months later.

UIK_02.2B, 2012.

AM: Did you have the impression that it was possible to tear down these walls?

HD: No. You can't tear down such walls, whatever it is that you do. But at the Kunsthochschule in Kassel, there was someone in every department who was interested. We then joined forces.

AM: Who was that?

HD: That was Prof. G. Mathias, Prof. H. Bauer and me. We initiated a lecture series called "Design, Art, Computer: Computers at the Kunsthochschule". In this lecture series, we invited people from outside, for example Peter Weibel, the long-time director of the ZKM in Karlsruhe, to make this topic known to the students. We were very successful with this.

The first computer pool at the Kunsthochschule came to be because of this group and with the help of these two colleagues. We later established the "Institute for Computer Aided Representation and Design."

Throughout the university, I advocated for the founding of an interdisciplinary CAD Working Group, which ultimately comprised eight departments. This group had the necessary resources, rooms, equipment, software, and personnel. We were then able to build on this interdisciplinary working group.

I would also like to mention the Society for Electronic Art and its long-time leader Dr. W. Schneider, museum director in Gladbeck, who organized an annual exhibition and introduced the Golden Plotter of the city of Gladbeck.

One thing is also critical: I had countless interactions with colleagues, students, and research assistants. It was a pleasure to work with these incredibly bright individuals. Teaching in partnership with these assistants and students in a new way – that is, much more jointly than I had experienced it as a student - gave me a lot of motivation.

I would say the support actually came from those I was supposed to teach. So I certainly filled the professorship a bit differently than is the standard. And from that, again, interesting suggestions came back that otherwise wouldn't have come. We actually worked together on things that none of us had any idea about at first. Of course, that's typical for design: The task you're tackling is always unknown. You don't have a solution.

tree_16_on_pink, 2023.

AM: There are three topics that still occupy you as an artist. The line. Unsharp images. Landscapes. Looking at the history of art, landscape is a genre with a long tradition. How did you approach creating landscapes with lines and code?

HD: I begin with walking. I wonder about what I see. Walking with open senses is a privilege. It makes me happy and focused. The rewards are an abundance of visual impressions in detail and mental explorations to capture what I’ve seen in nature and around me with the means that interest me: code and plotted lines. It could be a group of tall poplars in a strong wind, a large tree branching out from its massive stem, pebbles in a dry riverbed, or a landscape stretching to disappear into the distance.

Next, trials on possible programs may follow. A programmed drawing in a plotter file contains many vectors. They have mathematical properties and can be subjected to standard mathematical transformation operations. When physically plotted, the properties and shortcomings of pen and paper and the mechanics of plotting introduce less controllable layers of visual effects that can only be judged after a plotter drawing is completed. This means there is a time-consuming process of trial and judgement before a work is finished.

AM: Your landscapes are either abstract or figurative. In 2001, you created an artwork titled YELLOW TREE, which was shown in several exhibitions. I’ve recently read an interview with Vera Molnár, which made me think of your YELLOW TREE. In it, she recalls seeing her cousin draw the trunk of a weeping willow in ultramarine blue. "This struck me for life, it gave me the courage to transgress, to think a little differently. It was unforgettable", she said in that interview with Vincent Baby. Why did you decide to code a yellow tree on a blue background?

HD: YELLOW TREE is a print. I used code from the world of plotting and ventured into the world of printing, which is very different. One cannot plot a blue background identical to the one in YELLOW TREE with a pen. You may consider blue as the idea of a wide-open and inspiring sky, and yellow is what grows and ripens on the soil of the earth.

I think moments like the one you cited from Vera Molnár are thrilling experiences and have a substantial mental impact. In 2001, it was probably far less revolutionary for me to use yellow for a tree than it may have been in Vera Molnár’s youth.

In the design (and I use the term design deliberately) of YELLOW TREE, I was confronted with very few decisions: the design of a piece of code that makes use of randomly generated, however somehow predefined, polygonal lines consisting of straight line segments; a color for the object generated by those lines; and a color for the background. It is – in my opinion – the strictness and simplicity of this setup that are of interest for its qualification as an aesthetic event.

AM: After more than 30 years, what still fascinates you about the topic of nature?

HD: Structures in or of nature are a prominent topic in art. I had a flash of insight as a young architectural student when I first encountered the photographic work of Karl Blossfeldt. And we know that many of the shaping forces in nature follow mathematical rules, e.g., the Fibonacci sequence. Order, all kinds of arrangements, but also chaos all follow rules. In the branching of trees, we encounter a fantastic variety. And if motion is added, for example, by wind, things may appear unsharp, even though they are not. For the design of aesthetic events, we can play with the shortcomings of human sight. I did that in the two examples of TREE_16 ON BLUE and TREE_16_ON_PINK.

There is another aspect hidden in the generative concept of YELLOW TREE that is very important to me. I regard it as fundamental for my code-generated line art. When drawing a line, no matter by which process it comes into existence, its starting point is placed deliberately. It is an important decision. We can mentally reduce a generative drawing to a set of starting points on a plane.

And in the code, these points really do exist. I think it is important to see the tremendous freedom of decision we have in generative art. We can generate an entire line drawing from a tiny, arbitrary area on a plane filled with a very large number of starting points, or we can also see the other extreme as well: an entire drawing from only one single starting point. In many of my works, I have followed this line of thought right from the beginning.

Yellow Tree, 2001.

AM: You worked constantly with plotters and dealt with questions attentively and patiently. What motivated you at the time and led you to work with mechanically generated lines? What did you discover about lines?

HD: The line is extremely intriguing to me. Actually, rock paintings are where art begins. The line is straightforward. There is a beginning and an end point. What occurs in the meantime is entirely up to chance. I assert that there is a line universe. It's a distinct, limitless universe.

The interesting thing about these early plotter artists is that they each developed their own type of line for their drawings. Jean-Pierre Hébert, Roman Verostko and I developed different line types with the programs. You can immediately identify these drawings. This is a Hébert. This is a Verostko, this is a Dehlinger.

For this, it is necessary to grasp the line algorithmically. I did it like this: The beginning is set relatively clearly. The end point can be left open for the time being. And what happens in between – you have to program some things for that.

In my case, this is a polygonal line, i.e. a polyline. There are length differences, angles, spread and more. You can program all this and influence it with random numbers.

For this reason, the line is an elementary and fascinating entity that lends itself very well to algorithmic generative approaches. You may also create surfaces, which I did as well. When the lines are tight and parallel, the drawing forms a surface.

AM: How do you get started on a new piece?

HD: Often a question is in my mind for an extended period of time. I begin by taking notes and gradually get more concrete. This can take a long time. I've been working on a project involving three-dimensional sculptures for several years.

Algorists (from left to right): Roman Verostko, Channa Horwitz, Jean-Pierre Hébert and Hans Dehlinger in Channa Horwitz's studio in Santa Monica, CA, USA, 2005.

AM: Has anything changed in your influences from then to now?

HD: It's getting harder and harder to get the old plotters repaired. Maybe that's why I'm exploring the 3D field now: because once again there are new technologies to do stuff with.

AM: Does your architectural background have an impact on your artistic work?

HD: Definitely. And, in particular, the design theory that I mentioned previously. The imagination – it’s exactly what Max Frisch does in his novel "Mein Name sei Gantenbein"; he was an architect. He uses this recurring phrase: "I imagine..." That is the constant preoccupation of architects: how do you come up with an idea? What is your interpretation of something? What is the answer?

And these solutions are never what is known as an optimum in mathematics, such as an optimal point. There is no such thing here. It is equally optimal to be here or there. However, it is not equally good. Design theory is a wonderful foundation for such work - envision, grasp, and then create. You can then judge the result, others can judge it, and you can alter it. Typically many such iterations are developed, condensed, and then one or two are picked.

Berlin Airport Express, 2007.

AM: Is abstract art something that influences you?

HD: I believe that ideas for these things can come from everywhere. It can be abstract art or even a train schedule, as in my "Berlin Airport Express" project. Or a cigarette vending machine. I imagined at the time that these five brands, Roth-Händle, Ernte, and so on, may serve as the basis for a generative drawing. So the occasions are so diverse and multi-layered that no definitive assertion can be made in regards to their origin.

When we were in China, it was difficult to convince students that a drawing without a figure is art. Art is entirely arbitrary. Finally I said to the students: "We're going to do a 'random walk' with the camera. You hold the camera in your hand, pick how far you want to go straight ahead, how many degrees you want to turn, how close you want to get, and then press the shutter. Then there's the occasion for your art, which is what's in the picture.” One of them really got it and and then used it to create some really amazing abstract paintings.

So actually you can use any occasion, anything that comes into your head. You just have to put some thought into it. You have to analyze and, of course, have some knowledge of what conditions generative art has and what you need for it. Then you can take sounds, colours, objects, collages, patterns etc. and create aesthetic events from them.

AM: You have been following the evolution and history of generative art for several decades and have actively contributed to shaping it. What do you imagine art and technology to be like in five years?

HD: The terms art and technology, or rather, this pair of terms – art in conjunction with technology – I’m sure will continue to exist, regardless of how technology advances. Artists will always find a way to interconnect the two. It is far more difficult to forecast where technology will go.

However, I do not believe AI will completely replace generative approaches. Certainly AI can be used generatively. You may also say that the "generative" in generative art arose in the last 30-40-50 years, with people like Herbert W. Franke serving as forerunners. It's not like what's being done with programs now is entirely novel.

It could also be that the AI becomes so independent that it simply spits out art, daily, always new art, somewhere, everywhere. That it feels the need to produce itself, to impose itself, and then the AI produces and places art everywhere. Seriously? I don't know.

exq0_vers_2pos_1.2_bw, 2015.

AM: When you look back on all the battles you had to fight, such as the fight for the acquisition of computers at the university: Do you have any advice for artists who have to fight battles again today, for example over the acceptance of artificial intelligence in art?

HD: Don't let circumstances distract you. By all means, keep going. Engage in deep conversations with like-minded people.




Read More