A team built a 3D simulation system for large terrains using virtual textures and topographic patterns. They used a combination of Creator Terrain Studio and Vega Prime to create a detailed terrain scene. By preprocessing data from Fujian, they were able to generate realistic textures and maps for the terrain. The system includes features like virtual textures, detailed models, and efficient organization of terrain data. This technology helps in creating realistic and immersive simulations of large-scale terrains for various applications.