topic Re: Z-values of a text file into a mesh? in Collaboration with other software

Z-values of a text file into a mesh?

Anonymous — Tue, 12 Jan 2016 10:49:48 GMT

Hi!
I have a text file(* which has thousands of Z-values separated by a space. I wonder is it possible to get them into a MESH using GDL script?
I’ve been able to read the values from text file using Text I/O add-on, and even put them into parameter buffer (using PUT command). But the problem is that I should be able to read them in ”inside” MESH command. Like:
mesh a, b, m, n, mask, [and then:] z11, z12, z13… etc.
I guess there is no way to do that?

*) Nevermind the lack of X- and Y-values here; the file format is Esri Ascii file where the X and Y are defined in the beginning of the file via coordinates, number of columns and rows, and cell size.

Re: Z-values of a text file into a mesh?

Erwin Edel — Tue, 12 Jan 2016 11:25:19 GMT

Try using http://arcscripts.esri.com/details.asp?dbid=15144 this converter to get XYZ format file and then read the xyz file from Options > Place Mesh From Surveyors Data...

Maybe that works?

Re: Z-values of a text file into a mesh?

Anonymous — Tue, 12 Jan 2016 12:01:09 GMT

I've already found that page. But unfortunately it's for ArcGis which I don't have. And I'm using Mac.
But: converter is made with python language. Is it so that it's not compatible with other applications? I have QGIS, instead...

Re: Z-values of a text file into a mesh?

Alex Moruzzi — Tue, 12 Jan 2016 13:41:38 GMT

From what I remember, you can place a for next loop inside the mesh command ...
Then use get nsp or so for the values

Re: Z-values of a text file into a mesh?

Anonymous — Tue, 12 Jan 2016 13:49:05 GMT

Alex wrote:
From what I remember, you can place a for next loop inside the mesh command ...

Ok, that sounds promising.
Thanks both of you!

Re: Z-values of a text file into a mesh?

Erwin Edel — Tue, 12 Jan 2016 13:54:59 GMT

Long ago I used excel and notepad and some copy pasting in between to generate my own surveyor data file from some coordinate values. I think I got that to work with the import data function in the end.

But it sounds like you have a LOT of values to work with.

I think you can import the esri into qgis and you might be able to export to XYZ or ascii coordinates there.

http://wiki.tuflow.com/index.php?title=QGIS_Importing_a_Grid

Re: Z-values of a text file into a mesh?

Erwin Edel — Tue, 12 Jan 2016 13:58:14 GMT

Can you share the esri ascii file here? I have QGIS installed, can have a look if it works.

Re: Z-values of a text file into a mesh?

Anonymous — Tue, 12 Jan 2016 14:04:01 GMT

Erwin wrote:
Can you share the esri ascii file here? I have QGIS installed, can have a look if it works.

I'll get back to this tomorrow. The original land survey .asc files are quite big, but I've made a small one to be tested with GDL object. I can send that one.
I know that .asc file works with QGIS, but the possibility to use python language add-ons is way over my capabilities.

Re: Z-values of a text file into a mesh?

Erwin Edel — Tue, 12 Jan 2016 14:16:34 GMT

From what I'm reading GRASS should be able to export the imported raster to xyz.

I'm using Windows 7 version of it.

http://gis.stackexchange.com/questions/45197/what-is-xyz-format-in-qgis

Re: Z-values of a text file into a mesh?

Anonymous — Wed, 13 Jan 2016 08:24:47 GMT

Alex wrote:
From what I remember, you can place a for next loop inside the mesh command ...
Then use get nsp or so for the values

I tried to google this, but couldn't find any references. Somehow it seems strange to be able to place FOR...NEXT inside MESH - or any other - command. I might be wrong. But while searching I found this:
http://archicad-talk.graphisoft.com/viewtopic.php?t=4683&postdays=0&postorder=asc&highlight=twisted+ribbon+object&&start=0
It seems that placing a GET command inside 3D shape command is ok. So no direct help but I learned some GDL basics!

Erwin wrote:
But it sounds like you have a LOT of values to work with.

Yes; the .ASC text file is 69 MB.

Erwin wrote:
From what I'm reading GRASS should be able to export the imported raster to xyz.
I'm using Windows 7 version of it.
http://gis.stackexchange.com/questions/45197/what-is-xyz-format-in-qgis

I checked the link, and it seems QGIS can do it. I tried this (from the linked page):
"You can use Raster->Convert->Translate form the Qgis menu, and edit the command line from -of Gtiff to -of XYZ. "Save As" is only working for vector layers."
I don't know, what editing command line -of Gtiff to -of XYZ means. I didn't see anything like that. The result is XYZ file. But something odd happens: file size is ca. 310 MB (compared to ASC 69 MB), and the Z-values has 13-15 decimal numbers. In ASC there is only 3.

Now I don't have time to try XYZ in ArchiCAD. I'll write some report here later.

So:
- GDL object which reads the ASC file would be nice if several people are using it (no need to use QGIS). But in order to work I have to edit file's couple of first rows by replacing several spaces with tabs. This is for GDL's TEXT I/O command.
- Using QGIS (if translate will be fine) is nice, since there's no need to edit the ASC file.

(I couldn't attach the ASC file...)

Thanks again!

EDIT: "It seems that placing a GET command...", not 'PUT'.

Re: Z-values of a text file into a mesh?

Alex Moruzzi — Wed, 13 Jan 2016 08:54:02 GMT

Sorry, I realize I did not use the for next inside the 3d instruction but prepared the buffer in order to use the NSP values using the "use" instruction inside the 3d instruction. No for next instruction in but before in order to prepare the buffer.

Re: Z-values of a text file into a mesh?

Anonymous — Wed, 20 Jan 2016 07:42:44 GMT

Here's an update.
I couldn't make the translation from QGIS reliably. Or kind of I could: the Z-values have 13 to 15 decimal numbers, but the rounded value is (quite) similar to the original value in ASC.

In the end I made the conversion with FME software, and it seems to be fine. I checked both ASC and XYZ files in QGIS and they look the same grayscale image. File size is around 200 MB. When I read it into AC using 'Place Mesh From Surveyors Data' it turned out to be impossible to handle; there is a point in every 2 meters and the area is 6x6 km's... But the benefit of XYZ file is that it's possible to decrease the rows in Mac's Terminal, for example by leaving every 10th (or anything) row only. That produces the mesh with points in every 20 m. This decreasing process couldn’t be done with ASC file.

Because XYZ from QGIS has many decimal numbers, it explains the difference in file sizes:
- XYZ from QGIS ca. 310…320 MB.
- XYZ from FME ca. 200…210 MB.

QGIS translation would have been better, because the software is free, while FME isn’t.

(I realized that of course XYZ is much larger in file size, because for every point it includes also X- and Y-values, when ASC doesn't.)