PostGIS

ST_IsPlanar — Check if a surface is or not planar

boolean +`*`+ST_IsPlanar*(`geometry `geom`)`;

Availability: 2.2.0: This was documented in 2.1.0 but got accidentally left out in 2.1 release.

This method needs SFCGAL backend.

This function supports 3d and will not drop the z-index.

This function supports Polyhedral surfaces.

This function supports Triangles and Triangulated Irregular Network Surfaces (TIN).