Three-dimensional shape data processing apparatus and non-transitory computer readable medium

A non-transitory computer readable medium storing a program causing a computer to execute a process for three-dimensional shape data processing, the process comprising:

• dividing a three-dimensional space including a three-dimensional shape constituted by one or more forming surfaces, which are flat surfaces or curved surfaces or include both flat surfaces and curved surfaces, into a plurality of three-dimensional regions each having a predetermined size,
• specifying, for each of the three-dimensional regions, one or more of the forming surfaces that interfere(s) with the three-dimensional region, wherein the forming surface that is in contact with or included in an interference range of the three-dimensional region is specified as interfering with the three-dimensional region, and
• redividing each of the three-dimensional regions until a size of the three-dimensional region reaches a size necessary for reproduction of a property of a portion of the three-dimensional shape expressed by one or more of the forming surfaces that interfere(s) with the three-dimensional region, wherein
• in a case where a property variation in a range of the one or more of the forming surfaces that interfere(s) with the three-dimensional region falls within a predetermined allowable range, it is determined that the size of the three-dimensional region has reached the size necessary for reproduction of the property of the portion of the three-dimensional shape expressed by the one or more of the forming surfaces that interfere(s) with the three-dimensional region and redivision of the three-dimensional region is stopped, and wherein
• in a case where the one or more of the forming surfaces that interfere(s) with the three-dimensional region constitute(s) a flat surface of the three-dimensional shape or in a case where there is no forming surface that interferes with the three-dimensional region, it is determined that the size of the three-dimensional region has reached the size necessary for reproduction of the property of the portion of the three-dimensional shape expressed by the one or more of the forming surfaces that interfere(s) with the three-dimensional region and redivision of the three-dimensional region is stopped, wherein
• the processor is configured to, in a case where variance of normal vectors of the one or more of the forming surfaces that interfere(s) with the three-dimensional region is equal to or less than a predetermined threshold value, consider that the one or more of the forming surfaces constitute(s) a flat surface of the three-dimensional shape.