Generate perfect curves when generating a section / elevation from 3D model?

[septembertiger168]

I love that AutoCAD Architecture have the ability to generate section/elevation from a 3D model, but it always breaks my curve lines into straight segments (I design a lot of curve roofs), is there a way to generate actual curves from the 3D model? or at least control the amount of segments to be generated so that the curve can look more smooth?

[David_W_Koch · Accepted solution]

AEC Objects do not do true curves.  The number of facets/size of the faceting is controlled by the FACETDEV System Variable.  This value is a distance, and represents the maximum distance from the midpoint of a facet perpendicular to the true arc of the curve.  So a smaller number will produce a larger number of facets.  The value has to be greater than 0.  There is also a minimum of eight facets on a whole circle, no matter how large you make the value.

Be mindful that there is a performance hit as you decrease the value of FACETDEV and increase the number of facets, particularly if you have long "arcs" of large radius.  There is another variable, FACETMAX, which specifies the maximum number of facets a single arc can have, with allowable values from 100 to 10000.  Setting FACETMAX to a lower value in its range can minimize the performance hit on long, large radius arcs while still allowing you to set FACETDEV small enough to get a reasonable number of facets on smaller arcs of smaller radius.