# CONVTOSURFACE [GstarCAD 2021](Help%20System/GSTARCAD/2021/Index.md) → [Commands](Help%20System/GSTARCAD/2021/Commands/(Commands).md) → [C](Help%20System/GSTARCAD/2021/Commands/C/(C).md) You can input the CONVTOSURFACE command or click Ribbon- Mesh – Convert to SURFACEto convert eligible objects into 3D surfaces. **Eligible objects include:**2D solids, 3D solids, Mesh objects, Planar 3Dfaces, Regions, Zero-width polylines with thickness, Polylineswith global-width, Lines with thickness, Arcs with thickness, Closed plane curve. **SMOOTHMESHCONVERT:** System Variable, only supports value 3\. Smoothness and optimization effect won’t be supported in the version. **DEOBJ** :System Variable, when sets the value to 0, the defining objects won’t be deleted, when the value is -3, there will be a two options for users to choose delete or not, when it is 3, the defining objects will be deleted. --- Gstarsoft Co.,Ltd