Import point cloud to ArchiCAD and make a terrain from it

[Anonymous]

Hi,
I found an interesting article which describes some of the steps needed in order to import a point cloud to ArchiCAD and make a terrain from that point cloud:
https://asiabim.wordpress.com/2016/02/10/importing-point-clouds-and-modelling-the-terrain

However the the final terrain looks a little bit "flat" so to say (photo attached below).

Is it possible to somehow make that terrain a bit more precise (meaning: it corresponding to the position of the actual point cloud points)?

Thank you for the reply.

[Laszlo Nagy]

I checked that article.
Basically you use the Point Cloud only as a Reference. Then you have to place many many Coordinate Dimension objects as the X, Y and Z coordinates of these will be scheduled then saved as Excel, manipulated there a bit to achieve the desired format, then saved as XYZ files. Then a Mesh placed based on those XYZ points. So the resolution of the Mesh that will be created from that XYZ file will be dependent on how many Coordinate Dimension objects you have placed.
The more you placed the more accurate the final result will be.
It is probably a good idea to place a lot more of them in areas where the terrain varies a lot.
In any case I would probably place hundreds of them before scheduling them and exporting to Excel.

[Anonymous]

Thank you Laszlo.

Can you suggest some better method of importing a point cloud into ArchiCAD and making a precise terrain from it?

[Laszlo Nagy]

Not that I can think of.
What would be a useful thing (and I don't know if there is such a utility out there) is a little program to reduce the number of points in a point cloud. So for example, if you have a Point Cloud file of 1 million points, this utility could reduce evenly the number of points to, let's say a 1000 points, then save it as an XYZ file.
Then you could import that 1000 point XYZ file into ARCHICAD and make a Mesh out of it. Then the Mesh would not slow down because of the high number of surface points in it.
If you tried to convert 100s of thousands or millions of points to a Mesh, that would pretty much kill it, I think.

[Anonymous]

Thank you Laszlo.

Would it be possible to explain this step a bit in detail please:

laszlonagy wrote:
Then you could import that 1000 point XYZ file into ARCHICAD and make a Mesh out of it.

I am interested in how to make a Mesh from those imported points.

[Laszlo Nagy]

Step 12. of that article details how this is done. It is a command in ARCHICAD. It takes a TXT file that contains a list of X, Y and Z coordinates and creates a Mesh based on it:

https://asiabim.wordpress.com/2016/02/10/importing-point-clouds-and-modelling-the-terrain/

[David Maudlin]

nedostizni wrote:
I am interested in how to make a Mesh from those imported points.

This is an article I wrote awhile ago, but still should re relevant: Creating a mesh from a txt file.

nedostizni: your signature looks out of date.

David

[Anonymous]

Thank you Laszlo and David.

@David: is your article made for rectangular (at least rectangular in 2d view) meshes only?
It's almost impossible to name which X, Y, Z coordinate coresponds to which point in a point cloud with randomly arranged points.

P.S.

I edited my PC configuration in my profile. Thank you.

[David Maudlin]

nedostizni wrote:
@David: is your article made for rectangular (at least rectangular in 2d view) meshes only?

No, this will work for any polygonal shape, but I think ArchiCAD finds the boundary then adds the other points to the interior (might not work correctly for an "S" type shape).

nedostizni wrote:
It's almost impossible to name which X, Y, Z coordinate coresponds to which point in a point cloud with randomly arranged points.

Understandable. This thread has a link to software that can reduce the number of points: Point cloud - Too many points.

nedostizni wrote:
I edited my PC configuration in my profile.

Thanks, shows you have the Place Mesh but not the Point Cloud import features.

David

[Anonymous]

Thank you for the reply David.
Let me just quote one part:

David wrote:

nedostizni wrote:
It's almost impossible to name which X, Y, Z coordinate coresponds to which point in a point cloud with randomly arranged points.

Understandable. This thread has a link to software that can reduce the number of points: Point cloud - Too many points.
...
No, this will work for any polygonal shape, but I think ArchiCAD finds the boundary then adds the other points to the interior (might not work correctly for an "S" type shape).

So If I understood you correctly, in case of rectangular (rectangular in top view) point cloud, it just needs to be exported from some other application (Rhino3d for example) in .xyz file, and imported to ArchCAD.

But if the point cloud in .xyz file is not rectangular (rectangular in top view), then it needs to be edited according to your article? Otherwise, the "S" shaped point cloud will look rectangular too?

Did I understand that correctly or not?