Several CAD related converters support both the AC3D (*.ac) file as well as VRML format and thus should help you with this conversion. Sometimes not all data can be converted because of the difference between formats.
Convert AC3D geometry data to Virtual Reality Modeling Language 3D model.
We found 2 software records in the database related to .ac to .vrml file format conversion.
Microsoft Windows software - convert ac to vrml on Windows
3D viewer and converter with huge file type support
Convert from ac file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned ac to vrml. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert ac to vrml on OS X
A Mac version of the popular 3D visualisation software