Sun Shines 83500 km日照十六萬七千里 (2018)
Digital installation with 3D static rendering of alternative perspective representation
High-performance PC x 1, Large Size Monitor (supporting HD1920x1080) x 1, 7” monitors x 3
Floor space: 4m diameter
高性能電腦，大屏幕顯示器支援高清(1920×1080), 7寸顯示器 x 3 ,佔地面積：4米直徑
In Sun Shines 83500km, a static rendering of alternative perspective representation is used to form a virtual environment. The visualization is based on a mathematical model contained in the Chou Pei Suan Ching (周髀算經 pinyin: zhoubi suanjing) compiled in the Zhou Dynasty (1046-226 BCE). It is one of ancient China’s earliest cosmological accounts, and also contains one of the earliest proofs for the Pythagorean theorem. The Chou Pei Suan Ching theoretical model of the cosmos does not align with our contemporary mathematical/physical understanding. The artwork is an outcome of twisting our visual experience, in an alternative perspective representation. It combines the simulation and modeling of the two astronomical systems, the ancient and the contemporary.
If the date and time are known, the position of the two suns from both models can be calculated and the moment rendered in an algorithm devised by the artist. Based on a 1953 postcard of the junction of Shang Hai Street and Pak Hoi Street in Yau Ma Tei, the distorted line of sight is applied to re-draw this everyday Hong Kong scene.
The work shows how a contemporary moment can be represented in an alternative perception. The project queries the authorization of our perception of space as an objective truth rather than a mental concept influenced by memory, imagination, and culture; then further solidified by evolving and accepted mathematical concepts.
《日照十六萬七千里》利用了另類透視的靜態繪製建構一個虛擬環境。 此虛擬現實的視覺呈現以中國古代已知的最早的宇宙論之一《周髀算經》所記載的數學模型為依據，當中所包含的，可能是中國最早的近似後來西方的畢氏定理的論証。 此作品源起的動機是嘗試扭曲我們慣常的視覺體驗，或說是為了追求一個另類透視法，但更想透過設合或遷就一個現今已不再被使用的數學模型去塑造空間，看出來的結果如何。 作品結合了現代所理解的古代和天文系統的模擬和建模。許維強找到1953年油麻地上海街與北海街交界的舊明信片，應用扭曲的視線以及透過對已知時日的太陽位置的演算，重新繪製1953年香港街道的日常場景。 它展現了對某個時刻如何在另一種感知系統中被「再」想像。《日照十六萬七千里》對我們對空間認知背後的理所當然的授權提出質疑。這種認知從來不是絕對客觀的，而是多少帶著心理的基礎。我們視為絕對的透視法受記憶、想像力和文化的影響，然後由數學概念進一步鞏固，也隨著時間的推移演變。
Sun Shines 83500 km was initiated by the artist’s study of alternative cosmology documented in an ancient Chinese mathematics treatise called the Chou Pei Suan Ching (周髀算經, Zhou Bi Suanjing) compiled in the Zhou Dynasty (1046-226 BCE). The imagined universe described consisted of both the earth and sky as parallel flat circular plates, 80,000 li (里) (approx. 40,000km) apart. Both plates had a cone protruding from the centre which pointed to the North Pole. The sun and other celestial bodies moved around the pole’s axis in seven circular orbits. These canopy-heaven hypotheses (蓋天說) were common in ancient times amongst many societies. However, most of these ancient cosmologies were related as mythological tales. What makes the Chou Pei Suan Ching special is its scientific and mathematical nature.
Based on observation, scientists use deductive mathematical models to explain experiences. Could artists act in a reverse direction? This project aims to twist visual experience to match a mathematical model in the Chou Pei Suan Ching. A non-Euclidean space is created in a virtual environment as a platform for visual study of a non-linear perspective representation, allowing a glimpse of an alternative perception suggested by an ancient model. That model would fail to match our contemporary visual experience, but it is still a self-contained model with its own axioms and deduced theorems. Some philosophers suggest that space is more a mental concept than an objective one. Over time this concept is supported by our cultural and scientific beliefs, then solidified by geometry in modern mathematical models, which return to further feed our perception. Thus, everything appears self-evident in a reinforcing loop. In the spirit of necessary critique, the artist queries the authorization of our space perception, and attempts to expand our visual dimensions.
Sun Shines 83500km is not only inspired by the Chou Pei Suan Ching, but also visualizes this piece of ancient Chinese cosmology projected onto a modern time Hong Kong site from the 1950s.
A three-dimensional space is built in a virtual environment. Any light falling on an object within it casts a shadow. Two light sources (virtual suns) are calculated based on two different models: the contemporary heliocentric model and the Chou Pei Suan Ching model. Comparing the light directions, neither of the cast shadows would align, either in shape or dimension. In order to match the shadows, instead of traditional linear perspective, a non-Euclidean space is created allowing for curving light rays, as well as curved lines of sight. It generates an unexpected and distorted visual rendering. The curved lines are not generated randomly, but based on an algorithm devised by the artist. The algorithm does whatever is necessary to twist the light rays, so that the result of the Chou Pei Suan Ching model can agree with contemporary observations, i.e. cast matching shadows in this non-Euclidean space.
In this exhibition, this distorted line of sight is applied to re-draw an everyday scene of a Hong Kong street in 1953. Based on an old postcard of the junction of Shang Hai Street and Pak Hoi Street in Yau Ma Tei, the street is remade on the artist’s virtual stage. Since the date and time are known, the positions of the two suns can be calculated and the moment rendered using the artist’s algorithm. The virtual space of an alternative perspective representation on different days of 1953 is generated as a result of applying the algorithm to various positions of the sun throughout the year. The work shows how a known moment would be represented in an alternative perception. To the artist, space does not exist as an objective truth but as a mental concept. This project queries the authorization of our perception of space as influenced by memory, imagination, and culture; then consolidated over time by accepted and evolving mathematical and scientific concepts.
Notes on the concept of space in the Chou Pei Suan Ching
The Pei (髀) in the title was an 8 chě (尺) (approx. 23.1cm) rod used as the gnomon of a sundial. If it was moved 1000 li (里) (approx. 500km) towards the sun from its original standing location, its cast shadow would be reduced by 1 cun (寸) (approx. 2.31cm) in length. This was the most important theorem defined in the Chou Pei Suan Ching (i.e. 日影千里差一寸). From it, other variables of the universe could be calculated. For example, the height of the sky was 80,000 li (里), the radius of the earth was 405,000 li (里), and the diameter of the sun was 1,250 li (里). This calculations were deduced by its proof of Pythagorean Theorem (勾股定理), as well as an axiom which assumed that the sky and earth were two parallel planes. Nowadays, we know this axiom is “wrong”, and its deduced theorem fails to match experimental observations. The shadow length would not be changed as expected. However, it is still a self-contained mathematical model.
Computer graphics 電腦繪圖 / shader programming 著色器編程 / ray marching / ray tracing 光線追蹤 / volumetric shadow mapping 容積陰影貼圖 / signed-distance function 符號距離函數 / non-Euclidean rendering / alternative perspective 另類透視 / immersive experience 體驗式經驗 / VR 虛擬實境
HUI Wai Keung Adam (許維強) received his MFA from the School of Creative Media, City University of Hong Kong. His works have been exhibited in in Hong Kong and overseas, including IFVA, 404 Electronic Art Festival, and the Milan Triennale. He was awarded Best Local Work IFVA, Media Art, 2017. In recent years, Hui has been active in artist-in-residency programs held in Europe and Asia, including the ARCUS Project in Japan and held a solo exhibition at the Goethe Institut Gallery in 2017. Having employed a variety of art forms, Hui now focuses on digital media including software, game, and generative art. His practice explores the possibilities of digital art to expand the horizons of human concepts and experience whilst maintaining traditional aesthetic values. He believes it is time for art to go back to the sublime, but with a new definition of the sublime.