In the Input parameters section of the dialog, choose whether to set a planar or angular tolerance and whether to create the regions from an STL format or a mesh.
In the Selection option section of the dialog, choose which part surface properties you would like to assign to the region.
Use the Regions from Mesh/STL command to consolidate all elements from a Midplane or Dual-Domain mesh, or from a model's STL representation, into a single editable region.