Visio diagrams are popularly used to create flowcharts, floor maps, and other technical drawings. However, a VTX file is a 3D model used by 3D modeling and animation programs. Sometimes, you may need to convert a VSD or VSDX file to a VTX file. This article covers how to convert a VSD or VSDX format Visio diagram to a VTX file programmatically in C#.