Open the Tools tab and click Orient Facets in the
Reverse Engineering group of the Tools tab.
Hover over the triangles to see a preview of the axis it would align
to.
Select the highlighted triangle.
The facet aligns as previewed. The selected triangle is shown in blue. Its
normal is aligned to the Z-axis.
With each selection, the align-to axis alternates between Z and Y. In the
next example, the normal of the selected triangle (shown in green) aligns to the
Y-axis.
As you hover over triangles, cylindrical areas are detected. The following examples
show cylindrical areas being aligned to the Z-axis.