Employ MAPCLEAN to Simplify a GIS Surface
Craig Batchelor, a Senior Application Expert for IMAGINiT, shows how to employ the Map 3D MAPCLEAN command and the Simplify Objects option to produce a smaller Civil 3D Surface from GIS data.
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Craig does a couple things in the demo that make me shudder, but his point of a smaller and more useable Surface produced by MAPCLEAN is a good one.
If you iteratively test the Simplify Objects parameter you will probably get to a more suitable result a bit quicker with less manual tweaking.
You can still process the MAPCLEAN results as Contour data which may be worth doing with some data sets.
Surface Weeding and Suplementing factors are a significant part of the TIN Wizard craft.
Left unsaid is the all too common problem of multiple forms of polyline/line data in public GIS data. Select and check the objects carefully.