Interpolate the level from the ground surface!!

Hi there!!

I've got a lot of points in auto cad (x, y, z). I'd like to build a ground surface and interpolate the level (z co-ordinate) at anywhere (x, y) in that area! help me! thanks in advance!!

here is my file!!

myfile.dwg

Hi there!!

I've got a lot of points in auto cad (x, y, z). I'd like to build a ground surface and interpolate the level (z co-ordinate) at anywhere (x, y) in that area! help me! thanks in advance!!

Pls have a look at this.

myfile-2.zip

that is great!! how do you do that? could you help me? by autolisp?

that is great!! how do you do that? could you help me? by autolisp?

There are many programs which can do this job. But I have only got AutoCAD and a free program called SiteTopo, see #3 in http://www.cadtutor.net/forum/showthread.php?p=212334#post212334 (pls download, view the video clip then play by yourself).

Follow these steps:

1. Command exptxt (LISP: exptxt.lsp) to export a text file of coordinates.

2. Use Excel to modify this text file to PENZD format.

3. Save as .csv format.

4. Run program SiteTopo.

5. Open modifed text file.

6. Save as .dxf

7. Run AutoCAD...

It would take a couple minute for doing this only.

Using SiteTopo, you will be very interesting with this little program. Cheers, PP.

exptxt.zip

Thank Phiphi very much indeed, you're very kind!!

I wonder could you help me to build the surface by using the Auto Lisp only?? I'm a beginner in Auto Lisp, so I'd to learn from Phiphi and everyone, thanks in advance!!

You're welcome, Badien.

I have no Lisp for this but using SiteTopo program.

It is so good. Cheers. PP

If you go through the steps Phiphi mentioned above you get a file you can open directly in SiteTopo:

badien1.zip

Thanks Charles Roberts!

Could anyone help me this problem in Auto Lisp or VBA??

This is a difficult problem to solve in general - as you are a beginner in lisp you will want to start with something easier I can assure you!

Good luck!

This is a difficult problem to solve in general - as you are a beginner in lisp you will want to start with something easier I can assure you!

 

Good luck!

I know this is a difficult problem, So I'd to learn more from everyone. I hope this problem will be solved and everyone can use the results as a effective tool for our job!!

Hi, I'm not sure that I quite understand what you are trying to achieve - maybe I am missing something really simple.

What do you mean by "interpolate" the level from the ground surface - this is a term I have never heard before.

I have had a look at your attached file, but what would you like done with the z-coordinate displayed in each text object?

Thanks

Lee

Lee Mac, sorry for my English and my expression is not clear!

From this text I'd to build a TIN (Triangular Irregular Network), the value of this text is the elevation of the surface (or z co-ordinate in Auto Cad). From the TIN I've done I'd to get the elevation (or z co-ordinate in Auto Cad) at anywhere in this area. So I used "interpolate" term (mean in mathematics) to show that I can get z co-ordinate ) at anywhere in each 3D face built from TIN.

Thanks Lee Mac for all your kind help!!

To build a 3D terrain model is a complex mathmatical task if you slow a terrain model right down you will see one method thats its based around a spiraling out of the object data always searching for the next point to join to and create a 3 sided object. Totaly forget about writing in it lisp. get the free versions!

If you still want to continue search the web for the mathmatics behind it first.

Lisps for cretating TIN's have been discusssed here before. But as mentioned it is a large task to create an accurate, efficient program, especially one that is useful that incorporates "feature lines" or breaklines. We are fortunate something like "sitetopo" is available to do this, free.

You might want to focus on the second part of your task, to get the z value of any point once the TIN/surface model is created. This is quite doable with lisp.

Thanks BIGAL and CarlB for the advices, I hope we will discuss with each other to build a Lisp routine can do that.

1. Build a TIN (Triangular Irregular Network).

2. Get the z value of any point once the TIN/surface model is created.

Cheers!!

if i remember it correctly free cad utilities from cad forum have TIN that but i cant browse now due to web restrictions here in our company.

http://www.cadforum.cz/cadforum_en/default.asp

There are many programs which can do this job. But I have only got AutoCAD and a free program called SiteTopo, see #3 in http://www.cadtutor.net/forum/showthread.php?p=212334#post212334 (pls download, view the video clip then play by yourself).

Follow these steps:

1. Command exptxt (LISP: exptxt.lsp) to export a text file of coordinates.

2. Use Excel to modify this text file to PENZD format.

3. Save as .csv format.

4. Run program SiteTopo.

5. Open modifed text file.

6. Save as .dxf

7. Run AutoCAD...

It would take a couple minute for doing this only.

Using SiteTopo, you will be very interesting with this little program. Cheers, PP.

Please iam very new to this site and i have registered today itself, and also can u provide me your email id & phone no please

There are many programs which can do this job. But I have only got AutoCAD and a free program called SiteTopo, see #3 in http://www.cadtutor.net/forum/showthread.php?p=212334#post212334 (pls download, view the video clip then play by yourself).

Follow these steps:

1. Command exptxt (LISP: exptxt.lsp) to export a text file of coordinates.

2. Use Excel to modify this text file to PENZD format.

3. Save as .csv format.

4. Run program SiteTopo.

5. Open modifed text file.

6. Save as .dxf

7. Run AutoCAD...

It would take a couple minute for doing this only.

Using SiteTopo, you will be very interesting with this little program. Cheers, PP.

please sir can u provide me ur email id and phone no

Saiswaroop

You asked for help. The answer would be for everybody having similar problems. Why to get help by e-mail? That's not the way things are going here. Let the question to be debated in the public, chances are to receive more answers.