Civil3d LandXML surface to Microstation Surface - Help

Posting this here in hopes of finding a CAD/Microstation crossover expert.   The situation:  We have a 5+ mile topographic surface in Civil3d2018 that we need to get into Microstation.  LandXML seemed like the way to get this done but have come to find out that MicroStation doesn’t hold the triangles created as part of the Civil3d LandXML export.  Basically it hold the points but then all of the triangle faces need to be flipped to match the Civil3d surface.  We were hoping one of the long time experts in both could provide us with some guidance.  This should be so easy yet it is so hard....or possible it's our ignorance but we have tried and searched high and low and have not found a solution.

  • Could you 'drop' the Civil3D triangles to line strings, and then use the line strings to create a new surface - to ensure the triangles stay as C3D made them? 

  • "It really should be easy but Microstation surface editing and creation tools are the worst ever." I notice you edited this line out of your C3D forum post  when cross-posting :-) 

    Message 13 in the C3D thread is what I meant. 

    "we have tried this method and can get the tin lines to come in correctly but they are in a Terrain and not part of a surface. That sentence makes no sense to me as I am not the one doing the work" - copied from the C3D thread.

    A terrain is a surface - are you actually trying to get a mesh, rather than a surface? If that is the case, you can convert the terrain to a mesh.

  • Thanks Mark. Yes i did modify my post slightly. Its not personal, but having used Cad for 30 years and trying to figure out the surface functionality in Microstation is mind boggling. In Civil3d its easy, you need a point you add a point, you need a breakline you add a breakline, you need a boundary you add a boundary.

    I think we're making some headway with the triangle faces but now our issue is the boundary.  The file is not holding the boundary so it is tinning all over the place. Any thoughts on that one?

  • Hi,

    Is there any reason you can't just reference in the surface dwg into a new 3d dgn and merge to master?

    We have found that the problem with Civil3D LandXML lies in the fact that c3d does not export breakline data in its XMLs so we always have triangle face issues going into other software from c3d.



    OpenRoads Designer 2022 R1 (10.11)  |  Microstation CE Update 17.1 |  ProjectWise CE 3.4

  • Just to be pedantic - you have used AutoCAD for 30 years. MicroStation is CAD too! :-)

    What 'vanilla' ACAD tool would you use to create the surface from the C3D triangles to include the boundary? If I was doing this, I would be using the terrain tools in OpenRoads Designer (for example) and would include the boundary in the terrain - not sure if plain MicroStation has that, as it is not a civil tool (nor is plain Acad).