ACIS (Spatial Technology)
ACIS is a 3D geometric modeling kernel developed by Spatial Technology (acquired by Dassault Systèmes in 2000) and licensed to CAD vendors as a foundation for solid and surface modeling. ACIS uses B-rep geometry and provides a comprehensive API for building CAD applications — AutoCAD, Autodesk Inventor, Fusion 360, IronCAD, and dozens of smaller products are built on ACIS. It competes directly with Parasolid (Siemens) as the two dominant commercial geometry kernels in the MCAD industry.
Why it matters
ACIS and Parasolid together underpin approximately 90% of commercial CAD applications. Understanding which kernel a CAD tool uses explains its interoperability behavior, data translation accuracy, and the geometric capabilities available to developers building PLM integrations. When two CAD files translated through STEP or IGES lose features or change shape, the root cause is almost always a B-rep representation difference between the source and target kernels.
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Cite this definition
Finocchiaro, Michael. “ACIS (Spatial Technology).” DemystifyingPLM PLM Glossary, 2026, https://www.demystifyingplm.com/glossary/acis-spatial-technology