Three-dimensional dynamic visualization of the long range gas diffusion contributes to disaster forecasting and assessment. Existing three-dimensional visualization methods, which calculate the gas concentration without considering the terrain and display the gas concentration in the local range by isosurfaces, cannot meet the demand for intensive calculation and dynamic visualization of gas diffusion over a wide range. This study proposes a virtual globe-based three-dimensional dynamic visualization method of the long range gas diffusion, consisting of a voxel-based multi-scale data model, a terrain-dependent multi-scale concentration field calculation method using graphics processing units (GPU), and a GPU-based multi-scale spherical ray-casting algorithm. The method is then applied to the long range natural gas diffusion and is evaluated according to the efficiency of the concentration calculation and dynamic visualization. The results show that the proposed method can achieve dynamic visualization of the long range gas diffusion above 30 frames per second.

远程气体扩散的三维动态可视化有助于灾难的预测和评估。现有的三维可视化方法不能在不考虑地形的情况下计算瓦斯浓度并通过等值面显示局部范围内的瓦斯浓度，无法满足对大范围瓦斯扩散进行密集计算和动态可视化的需求。这项研究提出了一种基于虚拟地球仪的三维长距离气体扩散动态可视化方法，该方法由基于体素的多尺度数据模型，基于地形的多尺度浓度场计算方法（使用图形处理单元（GPU））组成），以及基于GPU的多尺度球形射线投射算法。然后将该方法应用于远程天然气扩散，并根据浓度计算和动态可视化的效率进行评估。结果表明，该方法可以实现每秒30帧以上的远距离气体扩散的动态可视化。