The sunshine shines into the cold and icy Helan Valley, adding a touch of warmth. The agile rock sheep jump on the steep cliffs, occasionally crossing the deeply carved and shallow carved rock paintings on the rocks, and the ancient patterns seem to be instantly awakened. The Helan Mountains, spanning between the Ningxia Plain and the Alxa Plateau, have witnessed the fusion and collision of northern nomadic civilization and agricultural civilization for thousands of years. The nearly 30000 rock paintings scattered on the 250 kilometer mountain are known as the "history books on stones" and the "gallery of prehistoric human art", silently telling the vivid stories of ancient ancestors. However, as time passes and nature erodes, the totemic marks on the rock wall become increasingly blurred. How to preserve rock art information for a long time? Digital means have "saved the field" and given rock paintings a "digital life". When it comes to Helan Mountain rock paintings carved on stones, the most famous one is undoubtedly the circular "Human Face Portrait" rock painting - it is carved on a stone wall 40 meters above the ground at the mouth of Helan Mountain, with heavy circles of eyes and short eyelashes, a semi-circular outline that exudes a cold and stern expression, and a sun like radiance emanating from the top of the head. This is the most representative "Sun God" in Helan Mountain rock paintings. Every time I stand in front of this rock painting, it seems like I can hear ancient echoes. At the same time as feeling awe, I also marvel at the artistic achievements of our ancient ancestors. ”Li Jianping, the head of the Cultural Relics Management Department at the Helan Mountain Rock Painting Management Office in Yinchuan City, told reporters that some scholars believe that the cultural meaning of this "Sun God" painting reflects the early ancestors' natural worship of the sun, while others believe that it is a tribal totem and a praise for life. Although it is impossible to determine which layer of meaning is closer to the original ideas of our ancestors, it provides us with unlimited imaginative space to understand ancient human history, "said Li Jianping. Besides the 'Sun God', more stones are also telling history. Walking along the entrance boardwalk of Helan Mountain Rock Painting Scenic Area, rock paintings with different patterns and symbols can be seen everywhere on the cliffs on both sides. Some have become mottled and fallen off, while others are still clearly visible after being eroded by wind and rain. Standing in front of the grand group of rock paintings of "human faces", the human face with wide eyes, broad nose, and exposed fangs exudes a sense of majesty due to its rough lines and fierce expression. On the stone walls on both sides of the valley with a radius of less than 1 square kilometer around Helan Kou, there are 8 concentrated 'holy image walls', with a total of more than 700 human face statues, each with a different composition style and expression form. Li Jianping said that some scholars believe that this is the imprint of ancient people's worship and worship of gods and spirits. Archaeological research shows that nearly 30000 Helan Mountain rock paintings record ancient human life scenes such as grazing, hunting, worship, and entertainment, as well as various animal patterns and abstract symbols such as sheep, horses, cows, deer, tigers, leopards, etc., revealing the cultural connotations of primitive tribal natural worship and ancestor worship. It is a cultural treasure trove for studying the history of Chinese human culture, religion, and primitive art. In the Helan Mountain Rock Painting Scenic Area (Helan Mouth Rock Painting Protection Zone), there are nearly 6000 rock paintings within a 12 square kilometer protected area, which are densely distributed in the mountain pass, forming a "corridor of ancient human culture and art". From the early Neolithic Age to the Bronze Age, rock paintings were produced and distributed in different periods. From simple animal outlines in the early stages to complex social scenes in the later stages, from simple hunting records to ritualized worship and sacrificial content, this is a history of civilization evolution engraved on stone, "said Li Jianping. Ancient rock paintings come to life in the clouds. Standing in front of a rock painting at the entrance of Helan Mountain, staff member of Helan Mountain Rock Painting Management Office, Marina, carefully observed the rock surface from the side with a furrowed brow: "Look here, there is already a clear hollowing phenomenon. Helan Mountain is located in the transition zone between drought and semi-arid, with a large temperature difference between day and night, and thermal expansion and contraction cause great damage to the rocks." Weathering and water erosion, hollowing and cracking, mudslide impact, animal and plant growth activities, human behavior, and other factors can all have some impact on rock paintings. Traditional physical, chemical and other protective measures can delay its extinction to a certain extent, but cannot guarantee its permanent existence, and some rock paintings are located in steep positions, making even routine monitoring difficult. "Marina's words were filled with regret. A race against time for digital protection has begun. On the basis of the rescue protection of rock paintings, the construction of flood control protection facilities for rock paintings, and the construction of rock painting protection and utilization facilities, in 2020, the Helan Mountain Rock Painting Management Office implemented the "Helan Mountain Rock Painting Regional Surveying and Digital Preservation of the Body" project. Through various methods such as remote sensing images, unmanned aerial vehicle oblique photography, regional fine surveying, and the production of cultural relics protection engineering atlases, digital data was combined with computer visualization technology to simulate and present the rock painting scene in the 12 square kilometer protected area of Helan Mouth, and a three-dimensional visualization system for Helan Mountain rock paintings was constructed. Entering the Helan Mountain World Rock Painting Museum, a three-dimensional model of the "Sun God" human face is displayed on the screen. With just a click of the mouse, the model continuously magnifies, and every scratch, weathered spot, and even the tiny crystal structure of the rock surface are clearly visible. We have imported all the surveying data of Helan Mountain rock paintings into this digital library, and finally built a 'virtual twin' of Helan Mountain rock paintings, "said Marina. Currently, we have collected 170000 clear images, 519 sets of rock painting surveying data, and centimeter level and millimeter level 3D models of the entire protected area and key areas. Liu Siwen, the head of the Rock Painting Research Department at the Ningxia Cultural Relics Protection Center, told reporters that traditional rock painting surveys mainly rely on manual observation, measurement, and recording. For rock paintings that are far away, located high, and cannot be observed up close, they are usually captured using long and short zoom lenses to obtain the image of the painting. The exact location and specific size of the rock paintings are mostly estimated. Nowadays, the rock art information collected by the most advanced digital means is detailed and accurate. After data collection and systematic processing, it can not only fully display the overall distribution of rock art and regional natural geographical environment information, but also truly reflect the preservation status and main diseases of the rock body where the rock art is located, providing strong information and data support for the research and protection of rock art, "said Liu Siwen. The "Gallery of Ten Thousand Years" encountered digital light and gave each rock painting a unique ID, linking its 3D model, attribute information, research literature, protection records, and more. Through the database, specific information about each rock painting can be queried, including its spatial position within the mountain. The physical rock paintings will eventually blur, but their digital lives have just begun. ”Marina told reporters. With digitalization giving it new life, this "history book on stone" is no longer just a silent pattern on the cliff, but has become a cultural gene that can be touched, explored, and disseminated, continuing to interpret the praise of history and life. (New Society)