1. A computing device comprising: an input device, a display device, and at least one processor; and a storage device storing a computer-readable program comprising instructions that, when executed by the at least one processor, causes the at least one processor to performing operations comprising: obtaining a point cloud of an object and converting the point cloud into a plurality of triangulated grids using a plurality of triangles; selecting a part of the triangulated grids from the point cloud to be simplified, and receiving a number of simplification passes to simplify the triangulated grids from the input device; classifying the triangulated grids into different types of triangles according to a shape of each grid and a location of each grid in the point cloud; simplifying each type of the triangulated grids to obtain a plurality of simplified grids by performing a loop triangular grid function with the number of simplification passes; and smoothing the simplified grids to obtain a point cloud model of the object, and displaying the cloud model of the object on the display device.