Real-time Volumetric Cloud Visualization of Meteorological Simulation Data

Notes: This archive contains a cyclone simulation as png/csv files and as Unreal Engine 4.27 assets. Documentation can be found in the linked git repository. Abstract: I present a concept for visualizing realistic volumetric clouds in real-time in the Unreal Engine using a scientific weather simulation as a basis. From the simulation files, I extract and compress non-linearly spaced variables such as cloud density, rainfall, and wind speed. Cloud density is used as the basis for ray-marched volumetric clouds in Unreal Engine. The clouds use wind speed as a flow map and rain density as a color map. I add Voronoi noise to the clouds and mask it with wind speed to add dynamic detail. I am also able to animate all time steps of the simulation in real-time. A user study shows that most of the added effects improve realism and my implementation is five out of six times more realistic than previous methods. The median performance of a playable prototype on consumer-grade hardware is 128~FPS and meets the performance target.

说明：本存档包含以PNG/CSV格式存储的气旋模拟数据，以及虚幻引擎4.27（Unreal Engine 4.27）资源。相关文档可在关联的Git代码仓库中获取。摘要：本文提出一种以科学气象模拟为基础的实时可视化方案，可在虚幻引擎中渲染逼真的体积云效果。研究人员从模拟文件中提取云密度、降雨量、风速等非线性分布变量，并对其进行压缩处理。以云密度为基础，在虚幻引擎中通过光线步进（ray marching）实现体积云渲染；将风速作为流动贴图，降雨密度作为颜色贴图。此外，为体积云添加沃罗诺伊噪声（Voronoi noise），并通过风速对噪声进行遮罩处理以增强动态细节。本方案还支持对模拟的所有时间步长进行实时动画播放。用户调研结果显示，绝大多数新增效果均可提升渲染真实感，且本实现的逼真度较此前方法高出5/6倍。在消费级硬件上运行的可游玩原型帧率中位数可达128 FPS，符合性能目标要求。