I’m trying to get a “.3ds” file and a AutoCAD 2004 “.dwg” file from the “.max” file.  I need to import the
“.3ds” file into an ArcGIS geodatabase as a 3d multipatch, for use in ArcScene.  When I export the file
as either a “.3ds” file or an AutoCAD file, the cylindrical shapes become either jagged or squared
along the edges.

What version of VIZ are you using?  Export shouldn’t corrupt or change the geometry.  After you do the export, import it back into VIZ and see if the geometry is intact.  Make sure your weld threshold is set to 0 or something very low, and your surface deviation is also set low.  If the geometry is ok in VIZ, then the problem is on the CAD program side.

The problem you describe is usually the symptom of vertices being welded when they shouldn’t be.  Also I’ve seen geometry getting corrupted if you are importing solids with the Surface Deviation value set too high.

Pixels, Polygons, get’m while their hot

viz 2008

I just tried it in viz 2008, no problem here.  When I import the DWG back in, I had to turn on Cap to get the geometry in correctly.

I think the issue is going to be in the import settings for your CAD program on the other side.  You might try exporting to AutoCAD DWG 2000 and see if the problems are the same.

Since you are trying to create a “3D multipatch” (whatever that is], you might try collapsing your model to patches in max first and see if that screws things up - smells like the patch conversion is the issue.

Pixels, Polygons, get’m while their hot

have you tried converting the entire max scene to poly’s then welding all vertices?
that’s my usual workflow when exporting to 3ds as some software doesn’t seem to like to import objects that have modifiers on them.

good luck. let us know how you get on.

dual xeon 5345 - gtx 570 - 4gb ram - vista business x64 - 3ds max design 2011 x64 - vray 2