In this paper, we explore a new road for format-compatible 3D object encryption by proposing a novel mechanism of leveraging 2D image encryption methods. It alleviates the difficulty of designing 3D object encryption schemes coming from the intrinsic intricacy of the data structure, and implements the flexible and diverse 3D object encryption designs. First, turning complexity into simplicity, the vertex values, real numbers with continuous values, are converted into integers ranging from 0 to 255. The simplification result for a 3D object is a 2D numerical matrix. Second, six prototypes for three encryption patterns (permutation, diffusion, and permutation-diffusion) are designed as exemplifications to encrypt the 2D matrix. Third, the integer-valued elements in the encrypted numeric matrix are converted into real numbers complying with the syntax of the 3D object. In addition, some experiments are conducted to verify the effectiveness of the proposed mechanism.