ACIS是美国spatial technology公司的产品，是应用于CAD系统开发的几何平台。它提供从简单实体到复杂实体的造型功能，以及实体的布尔运算、曲面裁减、曲面过渡等多种编辑功能，还提供了实体的数据存储功能和SAT文件的输入、输出功能。-ACIS is a product of the spatial technology company, is applied to the geometry of the CAD system development platform. It from a simple entity to the modeling of complex entities functional entity, Boolean operations, surface cuts, surface transition a variety of editing functions, it also provides data storage capabilities of the entity and SAT files input and output functions.