I did not understand your term "actual" contours !!
In C3D the contours visibility can be set in its properties. You can also
set the layer, interval etc. When you open an exported surface, C3D is
using a default setting in properties. You can access and make your choices
and make the surface look as you want.
All contours are polylines in essence.
Hope this helps.
On Mon, May 21, 2018 at 4:44 PM slahann@cap-az.com <trimble@jiveon.com>