From DWG to MESH... a trick

[NandoMogollon]

Hi,
You all may be familiar with the AC14 new option "Place Mesh From Surveyors Data"...

It is a really fast way to create real terrains with just a few clicks. The only problem is that you will need a txt or a xyz file, and not all surveys provide with them, some will give you a dwg containing contour lines at real height.

There is a workaround to use the "mesh from surveyors" option with that dwg file:

• 1- open the DWG as an object
  2- copy the 3D script to a text editor (just the lines) and save it as txt
  3- open the file in MS excel (using commas as separators)
  3- use find & replace to replace the LIN_ text with a space
  4- at this moment you will have 6 columns
  5- take the last 3 and place them at the end so you can have a list of X, Y and Z values
  6- save it as a txt , again using commas as separators

now you can use the "mesh from surveyors" option by selecting the txt file.

It worked for me with more than 12000 points, so it pretty reliable.
just be aware of the amount of polygons generated when viewing on 3D.

Let me know if any clarification is needed.

Regards

Nando

[Barry Kelly]

s2art wrote:
First up - where has the "Place mesh from Surveyors Data" command gone? Doesn't seem to be in the design menu in AC20 (it is in AC19).

FILE menu > File Special

s2art wrote:
Second - does anyone understand line 5 in Nando's description?

5- take the last 3 and place them at the end so you can have a list of X, Y and Z values

I don't quite understand.

Take the last 3 columns? and place them under the first 3?
I am not sure - been a long time since I tried it.
What you should end up with is 3 columns for the x,y & z values.

Nando did list a slightly different set of instructions but maybe because that was for a diffent file?

The procedure to obtain this TXT file was:
1- Open the DWG as an Object
2- Copy the 3D script and Paste it into a simple text editor like Notepad/Textedit
3- Save it as TXT
4- Open the TXT in MS Excel
5- Clean the content in order to obtain separate columns with X,Y,Z values
6- Save it again as (the final)TXT

s2art wrote:
I do re-save as a .txt file (without step 5) but I keep getting an error message saying "The selected file is not a Text files (*.txt) file. Please select a valid Text files (*.txt) file."

Not sure about this one.

Barry.

[mikas]

The last time I checked (ACv19), there needs to be color values too in xyz -format. ArchiCAD will not read the .xyz point cloud without color information embedded in the table.

My post on that: .xyz -files

It might be a tedious task to add these values with your choice of spreadsheet program, if it's a big data in question.

I do not know if things have changed in AC20.

[David Maudlin]

mikas wrote:
The last time I checked (ACv19), there needs to be color values too in xyz -format. ArchiCAD will not read the .xyz point cloud without color information embedded in the table.

The color values are needed for Point Clouds, not for Surveyor's Data input. Here is an article I wrote a while ago about importing X, Y, Z values via the Place mesh from Surveyors Data command: Creating a Mesh from a txt file.

David

[mikas]

David wrote:

mikas wrote:
The last time I checked (ACv19), there needs to be color values too in xyz -format. ArchiCAD will not read the .xyz point cloud without color information embedded in the table.

The color values are needed for Point Clouds, not for Surveyor's Data input. Here is an article I wrote a while ago about importing X, Y, Z values via the Place mesh from Surveyors Data command: Creating a Mesh from a txt file.

David

Whoops. Thank You for the link btw.
ps. Daily I'm using a finnish version of the ArchiCAD. Sorry for my misinterpretations. I do have to launch the international version of AC sometimes to match some vocabulary. You would not believe how different the vocabulary can be.

[David Maudlin]

mikas wrote:
ps. Daily I'm using a finnish version of the ArchiCAD. Sorry for my misinterpretations. I do have to launch the international version of AC sometimes to match some vocabulary. You would not believe how different the vocabulary can be.

No worries. I am pleasantly surprised at how well non-native English speakers can participate in this forum. Without screen shots the cross referencing of commands must be difficult.

David

[Anonymous]

Barry wrote:

s2art wrote:
First up - where has the "Place mesh from Surveyors Data" command gone? Doesn't seem to be in the design menu in AC20 (it is in AC19).

FILE menu > File Special

s2art wrote:
Second - does anyone understand line 5 in Nando's description?

5- take the last 3 and place them at the end so you can have a list of X, Y and Z values

I don't quite understand.

Take the last 3 columns? and place them under the first 3?
I am not sure - been a long time since I tried it.
What you should end up with is 3 columns for the x,y & z values.

Nando did list a slightly different set of instructions but maybe because that was for a diffent file?

The procedure to obtain this TXT file was:
1- Open the DWG as an Object
2- Copy the 3D script and Paste it into a simple text editor like Notepad/Textedit
3- Save it as TXT
4- Open the TXT in MS Excel
5- Clean the content in order to obtain separate columns with X,Y,Z values
6- Save it again as (the final)TXT

s2art wrote:
I do re-save as a .txt file (without step 5) but I keep getting an error message saying "The selected file is not a Text files (*.txt) file. Please select a valid Text files (*.txt) file."

Not sure about this one.

Barry.

Had some success with your suggestions, Barry, thank you. But then I found a document on our system written by a former employee which said to delete the last 3 columns (not place them under the others). Seemed to give better results, albeit from a different DWG file.

I did find that I had to open the TXT file created from Excel again in Notepad and save it again, otherwise I got an error message when trying to import.

So at least I have some 3D information now. Unfortunately the surveyor didn't go quite far enough in this particular case, so I have to ask him for more anyway

Explanation of procedure attached.

[NandoMogollon]

Nice to see this little trick is still in use!

I hope I could make it its own Add-On, do you guys think we have enough support to crowd-fund this?

cheers

[Paul King]

Has anyone come up with a way to import/implement break lines in imported surveyor's file?
As far as I can see, xyz format just creates a dumb triangulation mesh using survey points as nodes, with no way to reliably capture vertical steps in terrain (such as with retaining walls).

Auto generated triangles with end points straddling any step in terrain basically destroy and average out the step where this occurs - there is no intelligence about which nodes to link together to form the triangles.

In AutoCAD dwg files, a break line handles this situation by telling the triangles to not link across defined step boundaries. Unfortunately, ArchiCAD is not smart enough to create a mesh directly from a dwg, and requires the user to dumb down the data into xyz data points - as per the title of this thread.

Is there a better way?

I have attached an example xyz import that demonstrated the dumbing down of vertical steps, and the same survey data imported from dwg as an object, then converted to a morph - with steps intact

I need a way for this morph to be an editable mesh, or series of meshes

[Barry Kelly]

One problem you will have is that a mesh can not have vertical faces (i.e. it can not have 2 nodes on top of each other).
At least they never used to and I am pretty sure nothing has changed.

Barry.

[Paul King]

Yes, that seems to be behind the limitation. An obvious way forward would be for the importer to create a low mesh beside a high mesh wherever there is a break line (i.e. generate as many meshes as are required), or to make any steps very slightly out of vertical, or to generate a terrain morph instead, while making the morph tool capable of acting like a terrain mesh in 2D views and sections