Improvements in 3D scanning technology have allowed for the rapid and precise scanning of objects in three dimensions, including valuable cultural heritage items, producing detailed 3D point cloud data. However, traditional visualization methods that emphasize edges often lead to cluttered visuals, which can hinder clarity. To tackle these challenges, an international group of researchers has created a new technique that separately renders soft and sharp edges in 3D structures, greatly enhancing clarity and depth perception.
Recent advances in 3D scanning technology have enabled swift and accurate capturing of 3D objects, including those of cultural significance, resulting in 3D point cloud data. Despite this progress, traditional edge-highlighting visualization methods often create an overwhelming amount of lines, which can obscure understanding of complex 3D forms. In response to these limitations, a research team from various countries has introduced an innovative technique that distinguishes soft and sharp edges independently in 3D models, enhancing both clarity and depth perception.
Recently, enhancements in 3D scanning methods, particularly through photogrammetry and laser scanning, have facilitated the effective and rapid digitization of intricate 3D objects found in the physical world. These innovative techniques compile extensive point cloud data to create detailed models of object surfaces, consisting of millions of distinct points. This technological advancement serves numerous applications, including the digital scanning of cultural heritage items, allowing researchers to conduct deeper analyses of their structures. Nevertheless, the complexity of the gathered data frequently poses challenges, particularly when the scanned objects include internal 3D characteristics, such as uneven edges.
Edge-highlighting visualization aims to sharpen the understanding of intricate 3D forms by highlighting their edges, thus making the shapes and structures more recognizable. However, existing methods tend to falter with very complex items, producing excessive lines that compromise clarity while diminishing depth perception and resolution.
To tackle these issues, a diverse team of researchers, led by Professor Satoshi Tanaka along with colleagues Ms. Yuri Yamada, Dr. Satoshi Takatori, and Prof. Liang Li from Ritsumeikan University’s College of Information Science and Engineering, has crafted a pioneering technique. Professor Tanaka elaborates, stating, “Traditional edge visualization methods typically focus on sharp edges, leaving soft edges inadequately represented despite their prevalence in numerous objects. Our approach presents two significant innovations: dual 3D edge extraction, which processes soft and sharp edges independently, and opacity-color gradation, which boosts the visibility of soft edges with varying colors and opacities.” Their findings were published in Remote Sensing on October 09, 2024.
This groundbreaking visualization method utilizes dual-edge 3D extraction and opacity-color gradation techniques. The dual-edge extraction process evaluates sharp and soft edges separately by applying distinct thresholds, while the opacity-color gradation simultaneously modifies both the transparency and color of soft edges. This results in softer edges having sharper, thinner outlines which effectively illuminate the intricate details of 3D objects. Additionally, it produces a “halo effect,” subtly concealing edges in the background, thereby significantly enhancing the perception of depth. This method also improves the visibility of sharp edges by accentuating their outlines with softer edges.
The team tested this technique using real-world 3D point cloud data, including culturally significant objects. Their results indicated that the new edge-highlighting visualization method yields a clear and understandable depiction of entire 3D structures. Impressively, the computational time for dual-edge extraction closely matches that of standard binary edge extraction methods, while the opacity-color gradation visualizations can be rendered interactively. Moreover, this technique creates a more effective “see-through” effect, surpassing traditional transparency methods used in examining the internal features of 3D models. It also integrates well with existing transparent visualization techniques.
Professor Tanaka explains the broader implications of their work: “Our 3D edge extraction strategy is not just an enhancement but an expanded method capturing areas often overlooked by prior techniques. It provides archaeologists and historians the opportunity for in-depth visual analysis of cultural artifacts, while also giving the public a richer insight into historical sites, thus improving the technology available for exhibitions in museums and galleries.”
This innovative approach marks a substantial improvement in the visualization of 3D scanned items, aiding in the better understanding and preservation of cultural heritage artifacts.
