How to Convert Polyline to TIN Surface?

[imusulin1]

Hi All,

I have a bunch of topographical layers as polyines. How can I convert them to TIN surfaces?

From this:

To this.

In the past I got XYZ coordinates, so I was able to create a TIN surface.

But this time I have polylines. How can I convert them to TIN surfaces? I was trying to explode the polylines into lines and extract the XYZ_start and XZY_end coordinates. Then I read the data back and create a TIN mesh. But the .xls goes up to 65536 rows, and it seems I have more datapoints than that.

Is there any other way to go from Polylines to TIN Surface?

Kind regards, MB

[Pointdump]

Hi MB,
Let's see what you've got. Can you post your drawing?
Dave

[imusulin1]

Certainly. Version 2024 (and 2018)

[TerryDotson]

1. Display ToolSpace Panel.
2. Expand Surfaces, Create Surface.
3. Make sure Tin Surface is chosen.
4. Give it a name, click OK.
5. ToolSpace > Surfaces > Expand YourSurface
6. Expand Definition
7. Right Click Contours, Choose Add
8. Name: Contours (See Note Below)
9. Pick All Contours

Take a moment in the Add Contours dialog to evaluate the parameters as it may be that your polyline vertices are too dense which would make a much bigger TIN than needed.

[imusulin1]

Works good... but only in Civil3D: I can see mesh in a 3D view.

But when it moves to 2D top view, I don't seem to see the mesh (the same attached file), and polylines are back.

Also, in (regular) AutoCAD, I don't see the mesh in 3D view.

Do you know how to get the TIN mesh as an object I can move to AutoCAD?

I would like to see the mesh even when in a 2D top view.

[Joe-Bouza]

If you made the Surface as @TerryDotson described the triangle display is controlled by the surface style in use. See the display tab >>> view directions and turn on off  what is is desired.

to view in plain acad you need the style set and an object enabler installed or extract the triangles for surface.

FYI: Civil3d vernacular is triangles. Mesh is something other that may share points wit xy and different z. 

this may sound pedantic but there is a serious difference in the Civil3d world 

[Jeew-m]

Hi,

As Terry correctly pointed out you can use the create surface from contours option as you have polylines with elevation.

Since the polyline has so many vertices on the polylines, you can use 'WEEDFEATURES' command to remove some of the vertices to reduce extra weight on the surface. However, you need to do this carefully so that your polylines do not deviate from the original positions too much.

[imusulin1]

Can you please expand a bit on how to get the terrain mesh in the plane acad? I got the contours from the polylines, but the plug-in I am using later in acad requires 3D Terrain Mesh.

[Pointdump]

MB,
"...the plug-in I am using later in acad requires 3D Terrain Mesh."
OK, now we're getting somewhere. There are at least 6 different mesh formats. What program are you using and what format mesh do you need?

Dave

[imusulin1]

It is a Virto.CAD for solar design. It requires a terrain mesh.

But the problem I am having is that the mesh visible in Civil3D is not visible in plain acad.

I don't know how to make the mesh visible.

Even when I do the basic XZY import and create a surface in Civil3D (files attached); when I open the same file in plane acad, the mesh is gone.

[Pointdump]

MB,
I have no idea how to get what you need. I've never worked with meshes. But as Joe has said, Civil 3D triangles and AutoCAD meshes are 2 totally different concepts.
I guess step 1 is figuring out in what format you need your data. Does VirtoCAD accept CSV, PLY, or VTK formats?

What about other software, like Rhino? Have you seen >>>This<<<?
Dave

[imusulin1 · Accepted solution]

Find a way forward. I did EXPLODE the contour in Civil3D to get the triangles. In that way, I can see them in the plane acad, and the plug-in can recognise them. 

Not sure if this is the best or the optimal way.

[Joe-Bouza]

Explode is not the way forward.

as I said Civil3d will allow you to extract the triangles as acad 3d lines. This practice preserves the surface 

[TerryDotson]

I can see them in the plane acad, and the plug-in can recognise them. 

Not sure if this is the best or the optimal way.

---

Since you are willing to consider plug-ins, DotSoft's C3DTools can convert TinSurface (and GridSurface) objects to (and from) plain AutoCAD Surfaces, Meshes, etc.  Beware the conversion of *HUGE* surfaces as the results may be slow and/or unusable (for example SURFOFFSET won't handle the resulting large surface).