Fatal error and unsuccess export to IGES data format for large surface (MMS)

[georg.grebenyuk]

Hello all,

I had been finding ways to export from Civil 3D large surfaces (my example is contains of 2.26 mln point or 4.53 mln 3d faces). In forum there was that Post - and all was worked .. may be problem with so large files or smth else?

Below screen of surface (created by Point cloud) in Navisworks:

Most interesting thing that Civil 3D can't find MMS file that placed near drawing even if save as new drawing these files in directory!

File for experiments <<here>> .... I haven't any suggestions why it was happened. May be I must create 3D solids from surface? (= death of Civil 3D for so large file)

I tried on Civil 2020 Russian and 2021 (Beta). 

Screencast with my steps <<here>>

[Pointdump]

Egor,
I got same as you in both 2020 and 2018. I have no experience with exporting as IGES, so all I can say is, yes, using your same steps crashes Civil 3D. Maybe someone here will offer a solution.
Dave

[georg.grebenyuk]

Hi. Dave

Yeah, I tested on smaller model what contain os two surfaces. At that Case I extrude 3D solids and tried some iterations of export (look screen below):

Screen of data (small surface - 1762 points or 3105 3d faces; large surface 42117 points or 83852 3d faces).

As you can check size of IGES files more than other data's size. And I suggest that in operations when surfaces contain of a lot of points in Civil 3D there is "limit" he can't calculate those data (and of course need to extrude from surface 3D solids; why Civil 3D select surface I don't know. There are no data's filter and it bug in my opinion).