Curved edges shown as straignt edges

[MARK.PATERSON]

Im using Autocad MEP 2008 the current job im working on requires some tunnels to be drawn. Ive managed to do this by extruding a circle along a polyline and all looks good
But when i open navisworks and open the drawing either through exporting it or directly opening the DWG the tunnels all look like hexagons or Octogans any idea how to make them look like circles its very frustraiting.
I know that if you are to far away from the 0,0,0 origin the circle edges look more square but due to the project we are having to build the 3d model at actual grid references so its quite a distance from 0,0,0
Hope someone can help
Cheers

[dkoch]

Are you using a Mass Element or another AEC object for the tunnels, or is this an AutoCAD extrusion of a circle? The former I would expect to see as segmented approximations, with the number of segments depending upon the FACETDEV and FACETMAX settings.

Are you getting the desired results in MEP 2008 but only seeing the problem in Navisworks? If so, perhaps this question would be better asked in the Navisworks forum (http://forums.augi.com/forumdisplay.php?f=923).

[theald]

All kinds of objects display like this, I think the problem is similar to what happens when creating 2D sections of your 3D Objects. I know that with conduit the same thing happens in Navis - If you zoom in the are segmented polygons - just as conduit shos as hexagons in the 2D sections.

We definately need a mroe accurate representation of 3d objects like this in Navis and in MEP sections!