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An efficient Ray-triangle intersection algorithm for tunnel models

Ray-triangle intersection is an important operation in algorithms like ray tracing. Meanwhile, it is often the most time-consuming operation especially when there are a lot of triangles in the scene. In this paper, we proposed an efficient ray-triangle intersection algorithm for tunnel models. Its time complexity per ray is O(√n) with a very small coefficient, where n is the number of triangles in the tunnel model. Experiment results show that the algorithm outperforms many other spacial subdivision schemes like the regular grid and the kd-tree in a lot of cases. Another advantage of this algorithm is that its preprocessing is only related to the shape of the tunnel's cross section, which can be performed only once. As a result, plenty of time can be saved when users have to construct a lot of models with different parameters.