Topo surface

[sam.greetham]

Hello all,

I'm fairly new to revit and I am working on creating a topography map for a project. The site topography has been mapped in Autocad, with 3D polylines set at the correct elevations.

When I link the CAD file and try to create the topography, I select the area (layer) I need to create from import, revit picks up the points but then seems to draw its own boundary missing a large proportion of the points. This new boundary has no points along it, so I am unable to delete anything on the boundary (the boundary does seem to follow the correct elevation).

I have tried to add points to 'snap' back the boundary, this has no effect. I have also tried to simplify the surface, this has no effect either.

I can split the surface, use pick lines for the boundary and this does work, however due to the large size of the site and the number of boundary lines to select, this would take a huge amount of time.

Just wondering if anyone has come across this before or knows a way around this?

Unfortunately, I am unable to upload a copy of the file but the attached images should show the issue.

Thanks for any assistance.