boundaries from 3dfaces (surface from 3dfaces)

[Anonymous]

Hi everyone!

I would like to create a boundary around 3DFaces for the surface definition. The problem here is that I have to work with ca. 2M 3DFaces and all the known solutions are too time consuming..

I have tried:

- linewrkshrinkwrap - does not create the exact boundary around big number of 3DFaces + does not include inner islands

- totalboundary - does not work with 3D Faces

- converting 2M 3DFaces to Regions or Polylines - never ending process

Do you know of any other solution/lisp that could work here? The results is to have a C3D surface therefore if there is a way of creating surface fom 3DFaces that would be of the exact shape as the group of 3DFaces would also work.

I have also access to the GENIO files.

Any thoughts?

Many thanks 

[tmachado]

Hi @Anonymous, you can create a surface from 3dfaces.

Create a surface, under the surface definition add drawing objects and for the pull down list select 3d faces. 

[Anonymous]

Hi @tmachado!

Thank you for your replay.

I am familiar with the process of creating a surface from 3DFaces the problem is however that C3D continues triangulating in gaps between 3DFaces and would therefore need to define it a boundary. And that's where the problem begins. 😉

Thanks

[tmachado]

I see, thanks for the clarification, well it may be time-consuming but what I do in this cases is edit the surface deleting tin lines with a fence, I found that more effective and believe it or not faster than trying to create a boundary sometimes.

[neilyj666]

@Anonymous The shrinkwrap trick won't work on 3d faces for some reason.

The only way I have found to approach this is to FLATTEN the triangles but do not attempt to select all at once - do it several times although it still could take some time.

The GENIO file may have the linework rather than the 3d faces to help? Can you request an XML file of triangle data as this sometimes has the boundary included?

@tmachado - deleting with a fence is also useful but can be tedious if the triangle are very long and thin. I'd have thought that Autodesk could have come up with a solution to this issue as it is very common

It may be simpler to manually create a 2d polyline around the extremities of the 3d faces and use this as a boundary and add vertices as required to remove any spurious triangles

[Ranjit_Singh]

This may be possible through a custom LISP. Post in the Visual LISP customization forums here.

Good luck.

[Anonymous]

So if I understand your question correctly, you want to make a boundary around your surface that is made up of 3d faces?

Create a tin surface from the faces as @tmachado suggested, then go to the surface style display tab and turn off everything but the border.

[Anonymous]

@Anonymous - I want to create a boundary around bunch of 3DFaces and then use both - 3DFaces and the boundary to define my surface. Thank you for your reply though.

[Anonymous]

@neilyj666 - I had used this solution before. The thing is that I am working currently with 2.100.000 3DFaces and you can imagine how time consuming it would be to do it this way.

I have found a way of doing that - still time consuming but the whole work is done in the background and does not require your attention. You can export the 3DFaces to shape files (mapexport) then open it in a GIS software (I use QGIS - completly free) and then merge the 3DFaces into one polygon. Then you can leave it for a while depends on how many 3DFaces you are merging. Once done import the merged polygon/shape file back into C3D (mapimport) with ticked Import polygons as closed polylines option. This way you get exact boundary of the 3DFaces including gaps which you can use to define your surface.

Thanks

[neilyj666]

@Anonymous - Interesting I'll give that a try....QGIS to the rescue when Civil 3D again fails to deliver yet again....:(

This functionality really should exist in the core Civil 3D product as it is a continual issue that occurs

[neilyj666]

@Anonymous - can you give a step by step guide as to the process in QGIS?

Can the same outcome not be achieved in MAP3D?