Extract surface from Polyface Mesh

[Anonymous]

Hi there!

The purpose of this question is about how to extract surfaces from a polyface mesh.

My problem is that the ballast model of the project consists of several polyface meshes and I would like to get the bottom surface of the ballast bed, or the edges, at least. I would like to redefine the TIN surface of the existing ground from Infraworks. It could be done manually, however, the model is very large and complex so it is a very tedious and time-consuming task.

Do you know a possible solution for this problem? I have tried to convert it to a mesh and then either convert to a single surface, 3d solids or a NURBS surface, which did not work out because it only enables me to delete triangle by triangle.

Thank you so much in advance for your attention.

Best regards,

Carlos Jiménez.

[Karsten.Saenger]

Hi @Anonymous ,

I understand that you are trying to create a TIN surface from polyface objects or add polyface meshes to your TIN, correct?

A polyface consists of a representation of a plane with a certain slope (3D).

The image you are showing seems to represent a 3D solid (corridor) that was converted to a polyface mesh. The only way to add those to a surface in Civil 3D is to extract the according polyfaces.

The easiest and cleanest workflow would be to create a real Civil 3D corridor and a corridor surface representing the ballast part. That way you can directly use the corridor - ballast surface in InfraWorks.

Best Regards,

Karsten.

[Anonymous]

Hi Karsten,

Thank you so much, once again, for your support.

My problem is that I have not been provided with the alignment to create the corridor, which I totally agree that is the cleanest solution. The thing is that if I use that model to redefine the existing ground TIN surface, it would consider exactly the geometry above for the ballast bed, while I am interested only in the bottom surface to export it to Infraworks. Thus, the new ground would be perfectly defined to just import this ballast bed.

Do you know if there is any possibility to extract the bottom surface of this different meshes as just one single object? But again, I would understand that creating the corridor is the only and easiest solution.

Best regards,

Carlos Jiménez.

[Karsten.Saenger]

Hi @Anonymous ,

sorry, I don't know any easy workflow to extract just the ground level of the polyface meshes.
Maybe there is a workflow with AutoCAD tools or a workflow in 3ds Max?
But it looks as if it's quite a manual workflow....

Regards,
Karsten.