Sandvik, AI "sculpt" impossible statue

Inspired by some of history's greatest artistic geniuses, one company sought to emulate these peerless masters through the use of artificial intelligence.

With the help of AI, coupled with its own cutting-edge technologies, Sandvik Coromant called upon five of humanity's most remarkable sculptors to engineer a never-before-seen combination of their works into an impossible masterpiece.

While not as mainstream as other mediums, especially these days, sculpting has definitively left its mark on the world. If you think of history's most influential sculptors, there may be scant few that spring to mind, such as the Italian artist Michelangelo for his world-famous marble sculpture – David.

Or perhaps Auguste Rodin, a French sculptor who specialized in bronze and marble figures, with his most well-known piece surpassing even his name – The Thinker.

Possibly one might consider American sculptor Augusta Savage, one of the first artists to consistently represent Black physiognomy in the early 20th century. Elevating images of her heritage, her most notable piece is of her nephew, Ellis Ford, called Gamin (or street urchin in French).

Maybe you might be more familiar with toil and strife through German artist Käthe Kollwitz, whose breadth of creativity was more than sculpting but all depicting the effects of poverty, hunger, and war on the working class.

Finally, it could be Japanese artist Kotaro Takamura, known for his sculpting greatly influenced by Rodin and his poetry, both of which broke convention and traditional Japanese styles and introduced a revolution of artistry to the Land of the Rising Sun.

All of this said, when Sandvik Coromant engineers were tasked with creating an AI-generated, stainless-steel coalescence of some of history's most famous chiselers, their metal-cutting expertise was put to the ultimate test.

In partnership with parent company Sandvik Group, Sandvik Coromant, the subsidiary tasked with supplying cutting tools and services to the metal cutting industry, set to develop a statue utilizing AI modeling and cutting-edge manufacturing solutions.

The idea of a piece that combined the dynamic poses of Michelangelo's work, the musculature of Rodin, the somber tones of Kollwitz, the ingenuity of Takamura, and the inspirational defiance of Savage culminated in a work that spanned the influences of 500 years.

With all the pieces in play, a statue called "impossible" was brought to life.

Model to metal

Turning to renowned AI services such as DALL-E 2, Stable Diffusions, and Midjourney to create the initial 2D mockup of the statue through an art on its own – AI prompts. Once the design was chosen, the engineering enthusiasts used this as a reference to carve out a 3D model – which turned out to be a Herculean task, given the inexplicable nature of exacting work needed to bring life to the immaterial.

To give an insight into the challenges, the engineers labored hard to estimate the depth of the statue since two dimensions are flat and lack depth and perspective.

To tackle this issue, the team used human-pose estimators to complement the initial point clouds to be sure of the completeness and symmetry of the body (think like the motion capture markers used in 3D capturing).

The model eventually consisted of nine million polygons. For perspective, typical modeling used in video games or high-end 3D animation uses tens of thousands, not millions, as rendering takes a proportionate amount of time given to the amount of data needed to process. While the statue was not animated, it is still a great number of shapes.

Afterward, Coromant used multiple game algorithms to recreate the invisible fabric, which was followed by the use of 3D up-sampling – essentially the use of AI to fill in the blanks – that reintroduced the details that had been diminished by the previous steps.

The whole idea of this project was to challenge a task that was seemingly impossible to execute, given that there was practically no clear affinity between the artists, especially in terms of geography and time.

Nevertheless, as the group continued to work off the initial shape, much like in sculpting, one must trust the process. However, as this had never been done before, the outcome was anyone's guess.

And the team did not shy away from the challenge of overcoming the impossible.

"We could use aluminum – that would make the machining easier – but we don't want to make it easy," said Jakob Pettersson, Computer Aided Manufacturing and Machining Specialist at Sandvik Coromant. "We want to show what our software and tools can do, and believe me, the winding forms in this statue and translating this into classic industrial programs normally used for prismatic geometries, that is a serious engineering challenge!"

Sectioned into 17 individual components, the essence of the figure was brought to life with top-of-the-line machining tools, all programmed to follow the AI-generated design.

With the inputs established, the design mapped out, and all the material an art team could dream of, the initial estimate of eight tons of steel needed was reduced to nearly three tons through clever engineering, a 150-centimeter or 59-inch statue weighing roughly 500 kilograms (1,102 pounds) was slowly whittled down with high-speed cutting heads to birth "The Impossible Statue."

"We could definitely have done this in an easier way, but what's the fun in that?" said Henrik Loikkanen, Technology Area Manager at Sandvik Coromant.

Precision akin to Swiss watches

"We needed a phenomenally precise digital simulation to help us machine the statue," added Loikkanen. "Digital manufacturing means we can prove out that whole complex machining process beforehand. The only time we spent on machines, therefore, is the actual production time. It also meant we didn't produce a single scrap component during the entire project."

The challenge this project posed is evident from the output of the CAM programming – a whopping 40 million lines of G-code that were fed into their CNC machines. Add that to the fact that the precision of the machined statue was less than 0.03 millimeters (30 microns) in deviation, similar to the demands met by manufacturers of Swiss watches.

After finalizing the statue's design with AI and virtually simulating optimal ways to manufacture the statue using digital twinning, it was time to commence machining.

"We treated producing the statue as we'd treat machining highly specialized, complex parts like those found in the aerospace industry," said Loikkanen. "An additional challenge came from the statue's chosen material – stainless steel from Alleima – as ISO M materials are notoriously difficult to machine. The material group is characterized by its high work-hardening rates and poor chip-breaking properties during machining. Careful attention, therefore, must be paid to the tools selected for machining the material."

In the end, a statue that seamlessly blends the works of five artists was made possible. Furthermore, joining the nebulous nature of art with the cold logic of technology, a truly one-of-a-kind impossibility became a reality.