关键词: 三维模型, 三角网格, 体积计算

Abstract: Triangular meshes are widely used in many field.In this paper，a new volume calculation method for arbitrary triangular mesh is presented based on the triangles set of the mesh only.Give a projecting plane，sign volume of pentahedron for each triangle in mesh，which is constructed by the triangle and it projection in projecting plane，is computed.Volume of the mesh is algebraic sum of all pentahedrons’ signed volume.Triangles will be partition into several smaller triangles when necessary.Volume calculation method presented in this paper can computed volume of meshes rapidly and accurately.Applications of the method to compute volume for constructing moulding unit in simulating large water and hydropower project constructing，and test result of computing volume for triangular meshes with different number of triangles，it is proved the effectiveness of the volume calculation method presented in this paper.

Key words: 3D model, triangular meshes, volume calculation