You’ll create the top portion of the helmet mesh from a cube primitive using the image planes as a reference. Primitive objects are one method for starting 3D meshes because they can be modified to create other forms.
To create a cube primitive for the helmet mesh
A cube primitive is created at the origin with the dimensions you specified and one subdivision around the middle. This cube primitive is comprised of four-sided polygon faces called quads. Quad polygons are used frequently with 3D character models as they are easily smoothed and deform well when bound into a skeleton.
You can smooth the cube so it appears more rounded on the corners and subdivide it into smaller faces using the Smooth feature.
To smooth and subdivide the cube primitive
The cube primitive is smoothed and is rounded at its corners. The cube has also been subdivided into smaller faces.
The polygon faces are still four-sided even though their shape and position have been modified by the smooth operation.