Electromagnetic simulation acceleration algorithm based on improved SAH-BVH

Ray tracing is an important computational method in electromagnetism. To improve the efficiency of electromagnetic simulation, spatial division structures such as the Bounding Volume Hierarchy (BVH) are often used to accelerate calculations. Studies have shown that the traversal efficiency of the BVH tree is also affected to a certain extent by the distribution of scene primitives. In electromagnetic ray tracing with direction sensitivity, the distribution of scene primitives has a greater impact on BVH traversal efficiency. Therefore, to further improve tracing efficiency, this paper proposes a BVH construction method based on the local coherence of triangular primitives and their directional sensitivity. First, this method uses Morton encoding to spatially sort the primitives, thereby enhancing spatial locality within nodes and minimizing the redundant volume of the bounding box. Second, a local adjacency clustering method is proposed to further optimize the data distribution of leaf nodes. Finally, a direction-weighted scoring mechanism is proposed to prioritize traversal of triangular primitives closer to the emission source’s viewing angle and distance, achieving a direction-priority hierarchy and traversal acceleration that conform to the characteristics of electromagnetic wave propagation. Experiments show that in four typical scenarios, such as classrooms, residential areas, schools, and mountainous regions, the calculation results of the improved algorithm, while maintaining consistency with the baseline model, increase the calculation efficiency by an average of ∼15% and accelerate the electromagnetic simulation calculation process.