A porous scaffold is a three-dimensional network structure composed of a large number of pores, and triply periodic minimal surfaces (TPMSs) are one of the conventional tools for designing porous scaffolds. However, discontinuity, incompleteness, and high storage space requirements are the three main shortcomings of porous scaffold design using TPMSs. In this study, we developed an effective method for heterogeneous porous scaffold generation to overcome the abovementioned shortcomings of porous scaffold design. The input of the proposed method is a trivariate B-spline solid with a cubic parametric domain. The proposed method first constructs a threshold distribution field (TDF) in the cubic parametric domain, and then produces a continuous and complete TPMS within it. Finally, by mapping the TPMS in the parametric domain to the trivariate B-spline solid, a continuous and complete porous scaffold is generated. Moreover, we defined a new storage space-saving file format based on the TDF to store porous scaffolds. The experimental results presented in this paper demonstrate the effectiveness and efficiency of the method using a trivariate B-spline solid, as well as the superior space-saving of the proposed storage format.

多孔支架是由大量孔组成的三维网络结构，并且周期性的周期性最小表面（TPMS）是用于设计多孔支架的常规工具之一。然而，不连续，不完整和高存储空间要求是使用TPMS设计多孔支架的三个主要缺点。在这项研究中，我们开发了一种有效的方法来产生异质多孔支架，以克服多孔支架设计的上述缺点。所提出方法的输入是具有三次参数域的三元B样条曲线实体。所提出的方法首先在三次参数域中构造一个阈值分布域（TDF），然后在其中生成一个连续且完整的TPMS。最后，通过将参数域中的TPMS映射到三元B样条曲线固体，可以生成连续且完整的多孔支架。此外，我们基于TDF定义了一种新的节省存储空间的文件格式来存储多孔支架。本文提出的实验结果证明了使用三元B样条曲线实体的方法的有效性和效率，以及所建议的存储格式节省了空间。