Creating TIN surface with small grid spaces

[amirfarshadfar]

Dear

I have two types of surfaces (attach “NURBS before – after”), with either the dxf or step files, and I want to create “TIN volume surfaces” and create a colored map (rainbow map) to show their differences in the z direction. I sent these files to the Autodesk forum and one of your colleagues sent a file for me (attach “Autodesk file 1”) that he created this TIN volume surface with a very small grid spaces and high precision (attach “Autodesk file 2”).

In this regard, I created a surface (attach “My File 2”) and did the following steps to create this surface:

I imported the “step” file into the Civil 3D software and did the following steps to create the surface:

• Set FACETERSMOOTHLEV variable to 0

• Set FACETERDEVSURFACE as 0.0001 and FACETERDEVNORMAL as 10

• Execute MESHSMOOTH command and selected my surface

• Exploded the surface

• Run the LINEWORKSHRINKWRAP command and select all my 3D Faces

• From the Home ribbon, Create Ground Data clicked on Surfaces and clicked Create Surface and created my surface with a name

• In Prospector tab, Expanded the Surfaces node, expand the surface (named in previous step) and expand Definition. Right-click on Drawing Objects and select “add”, then select all my 3D Faces and check “Maintain edges from objects” and click OK

• In Prospector tab again expanded the surface’s Definition node and right-click on Boundaries and select “Add” and added all of the boundaries of the Surface and created name for it.

• In this step my TIN surface was created and it could be used now for the “TIN Volume Surface” option to compare with other surfaces and create a colored map (attach “NURBS before”).

, but the problem is that I need a surface similar to the mentioned surface (attach “Autodesk file 2”) which has more precision with small grids. How could I create a smaller grid surface with more precision? Could you please guide me in this process. I attach my file also as the “My File 3 .dwg”.

Thanks for your response

Sincerely

Amir Farshadfar

[VincentSheehan · Accepted solution]

How about using EDGESURF to create a mesh? Set the SURFTAB1 and SURFTAB2 to the desired density of the mesh. The default is 6. Once the mesh is created, explode it to get the 3D Faces. EDGESURF will work using Feature Lines.

[amirfarshadfar]

Thanks for your guidance. 

Could you please let me know how could I create boundaries around the model to use the “edgesurf” command and select the 4 created edges for creating the mesh?

If I use the command “LINEWORKSHRINKWRAP”, it just create a straight line without considering the curvature of the real surface. In addition, if I want to connect the grid cell with drawing the lines or polylines, they may not match the surface and fixed on the surface, so how could create boundaries to be used for the “edgesurf” command?

Thanks for your responses

I look forward to hearing from you

Amir Farshadfar

[udo.huebner · Accepted solution]

Just increase the U and V Isolines on the STEP imported ACAD "Surface" Object.

[udo.huebner · Accepted solution]

And when converting the Acad SURFACE to a mesh using MESHSMOOTH, execute MESHOPTIONS Command first

[amirfarshadfar]

Thanks for your guidance, but the problem is that when I import my 2 step files (“before.step” and “after.step”) into the Civil 3D software using the tab “insert” and then the “import” option, and then create my mesh using the command “meshsmooth” with the mentioned “meshoptions” setting, Civil 3D create mesh surfaces for 2 different step file which are completely match each other and cover each other and there is no differences between them (attach “my file 1”), as it should not be and there should be some differences between them in the z direction as you sent me in the attachment “Autodesk file 1”. The file that you created (attach “Autodesk file 1”) completely show there is difference between the surfaces, and that is true and it should be, but when I import the step files and even create the mesh with the related “meshoptions” setting, they are totally covered each other. What should I do in this regard?

I am also a little confused, because you mentioned I should use the option “meshsmooth” and put the setting of the mesh type in “meshoptions” on the “triangle”, but the mesh surface you sent for me is square (attachment “Autodesk file 1”). Are you sure that I should put the setting on “triangle” and not the “mostly quads” in the “meshoptions” setting? How did you create it?

In addition, you answered me in the following previous response of your colleague that mentioned I should use the command “edgesurf” and select my 4 boundaries to create the square meshes. Now, what should I do? Should I use the command “edgesurf” to create the square meshes or I should use the “meshsmooth” and instead put the setting on “mostly quads” in the “meshoptions” setting? How did you create the attachment “Autodesk file 1” for me? Which command did you use?

Because I think if I use the command “edgesurf” and select my 4 boundaries, it just creates a mesh surface which could be completely different from my surface, is not it? Since, the “edgesurf” does not take care how the surface could be and it just consider the  boundaries and create mesh between them, and my surface could be completely different from it, is that true?

I also attach my created civil 3d files as the “My file” attachment and again the surfaces that you created before as the attachment “Autodesk file”.

Could you please guide me what should I do in the following

Thanks for your response

Sincerely

Amir Farshadfar

[Joe-Bouza]

To create a greater precision surface you need more data. Anything else is a guess

[amirfarshadfar · Accepted solution]

I finally solved it in another way. I opened my dxf files in two different sheet and then copy them and paste them as the original coordinates in a new sheet and work on them and everything is ok.

I do not why the step files create like that, but the dxf files completely show the original and real case of the data and it seems working with dxf files is much better than the step files.

[amirfarshadfar]

Could you guide me how could I cut the edge of the imported and meshed surfaces (attachment "Cutting Edges") to match them with each other’s? Thanks