Create a solid from a 3D polyline

[Tyke]

As part of a larger job we have surveyed the top of a dry stone wall. The client now wants that we make a solid for him from the surveyed points with a height of 2000mm (the drawing units are in millimetres).

 

A 3d polyline was created from the lines joining the points and I have that in the attached drawing.

 

I'm not looking for someone to create the wall, but I'm looking for the method to do it, as it will certainly crop up again with this new client. I've tried many ways in both AutoCAD and Civil 3D but just can't create the solid.

 

All help would be greatly appreciated.

3D-wall.dwg

[scj]

Hi Tyke,

is the attachment okay for you (I made it in Bricscad)?

Greetings in the neighbour-county - hope, you have still dry feets!

Regards - Beste Grüße aus der Rhön -

Jochen

3D-wall_scj.dwg

[Tyke]

Hi Tyke,

is the attachment okay for you (I made it in Bricscad)?

Greetings in the neighbour-county - hope, you have still dry feets!

Regards - Beste Grüße aus der Rhön -

Jochen

 

Hi scj,

 

That's exactly what I'm trying to do in AutoCAD.

 

The question is HOW did you do it? and can you replicate what you did in Bricscad in AutoCAD? As I said, I need the method not the answer.

 

Thanks for asking and yes both of my feet are currently dry. We had a couple of roads that were swept away and the centre of town was all under water. Some neighbours got all the sludge from the river dumped in their gardens, but we escaped

[scj]

Hi Tyke,

fine - you survived the flood!

About your problem:

Yes you can do it in AutoCAD - of course (I only have an educational version here), but I used 2 helpful programs:

ABW-TRI (see http://www.ant-ares.de) to create 3-sided faces from the 3DPolyline

and F2S.lsp by Bill Gilliss (google for it) to create the 3DSolid laying under these faces.

Use the BREAK-command first to make 2 bounding 3DPolylines from your (closed) 3DPolyline.

ABW-TRI is originally for unfolding 3D-Surfaces, but the creation of the 3D-faces is a secondary effect.

BTW - I had some trouble with accuracy, your 3DPolyline is far from (0,0,0) so I moved your model first to 0,0,0

(and the result I moved back).

Regards again and Good luck!

Jochen

[Tyke]

Right, I have it now. You are the Jochen from Black-Cad, that also has the 3D LISP routines. Or am I mistaken?

[scj]

You got me...

Regards

Jochen

[hmsilva]

Tyke,

I noticed that the in the 3D Solid posted by scj, the lower part have always the same z, and as you had written

 

"The client now wants that we make a solid for him from the surveyed points with a height of 2000mm (the drawing units are in millimetres)."

 

I presume you don't want the lower "z" constant.

Is possible to do this in AutoCAD, but demands a lot of "manpower"...

Attached is a dwg with some notes...

 

Hope that helps

Henrique

3D-wall_h.dwg

[scj]

Hi hmsilva,

it seems to be more easy to give "height" for F2S.lsp bigger than 2000 and then copy the 3DSolid downwards for 2000.

Then the Boolean Subtraction should give the result.

Regards and Good luck!

Jochen

[hmsilva]

Hi hmsilva,

it seems to be more easy to give "height" for F2S.lsp bigger than 2000 and then copy the 3DSolid downwards for 2000.

Then the Boolean Subtraction should give the result.

Regards and Good luck!

Jochen

 

Jochen,

you are correct!

Just wanted to demonstrate a possible way to do so only with AutoCAD tools...and I wrote

 

but demands a lot of "manpower"...

Cheers

Henrique

[Tyke]

Thanks guys for the help.

 

@ hmsilva - I have not had time to look at your solution yet, but I will tomorrow.

 

I sorted out a solution too:

In C3D I created a DTM (DGM für Jochen) for the top of the wall and with a visual style of Drahtkörper (wireframe?) I exploded the DTM twice to get the 3D-faces

I then used a LISP routine from Udo Hübner (Faces2Solid.vlx) to project the 3D-faces down onto a 2D plane. It's a similar routine to F2S.LSP that Jochen quoted, but in German, for my non-English speaking colleagues here in the office.

I also had to move the 3D-faces close to 0,0 to get the LISP routine to work and then move the resulting solid back into position.

 

The height of the solid wall is not that important as long as it is below the surrounding ground and embankment. I gave the 2D plane a round number 2+m below the lowest point in the wall top and it works just fine.

 

Once again, thanks for your advice and time, it is appreciated.

[Tyke]

Tyke,

I noticed that the in the 3D Solid posted by scj, the lower part have always the same z, and as you had written

 

"The client now wants that we make a solid for him from the surveyed points with a height of 2000mm (the drawing units are in millimetres)."

 

I presume you don't want the lower "z" constant.

Is possible to do this in AutoCAD, but demands a lot of "manpower"...

Attached is a dwg with some notes...

 

Hope that helps

Henrique

 

@ Henrique

 

I tried to implement you method but it fails at the "_BPOLY" point. However I convertd the lower 3D polyline into a 2D polyline and then got your method to work exactly as you said.

 

But you did say it was very labour intensive and it certainly is. With a couple of hundred vertices in the 3D polyline it would take a considerable time to create the solid. My method is relatively quick and using the boolean functions in AutoCAD is also verstile. Jochen's method is very similar to mine but uses 3rd party software, which is expensive for the number of times I expect to use it. When I get a bit of time I shall write my own routine to implement it.

 

Thanks guys.

[mech]

This is a very Continental-based thread ^^

[steven-g]

This is a very Continental-based thread ^^

Oh no it isn't ..... Oops

[Tyke]

This is a very Continental-based thread ^^

 

 

But that's what CADTutor is all about, isn't it? But why so many expats?