If your points are inside a csv file
here for 20 points randomized inside a spreadsheet ;)

You can use Max's HeightMap script with the heightmap picture. Use Loft after the curves are generated.

http://moi.maxsm.net/

Wayne

Ref: From Mount Rainier heightmap
https://mattbooty.wordpress.com/2019/01/20/3d-printing-a-model-of-mount-rainier-using-digital-elevation-model-dem-files/

Thanks again for the pointers. I have some good news and some bad news....

The good news is that I managed to convert the ImportPointFile scripts to import multiple polylines from a single CSV file (1 polyline per data row).
This works well and the resulting curves simply require 2 joining lines - one along each end - to produce something that can be networked into a surface.

The bad news is that MOI struggles badly with networking the area I'm working on - in fact it never completes the job.
The area is approx. 2400m x 2400m with data sampled every 1m. That results in 2400 polylines, each line with 2400 data points.
That means we're connecting close to 6 million data points. I'm sure I could resample it but I need that level of detail I'm afraid.

Can anyone advise on a way forward please or suggest an affordable modelling package that might handle that kind of landscape size?
It's frustrating as I thought I was almost there. MOI is an incredible piece of software and I use it for all my modelling now. It's got to be the most well thought out modelling package out there but I suspect I'm pushing the boundaries here.

Thanks

Are you using MoI4 Beta? It handles more data... or memory or ...

I think I would use interpcurves instead of polylines.

- Brian

I am Brian, yes.

Maybe try Through pts import option?

Divide up the problem into 4 or 16 or 64 grid areas?

Try out a smaller grid for proof of method?

- Brian

Also it is unclear if you are doing "column" polylines, or "column" through point curves.
Or just joining the ends of the "row" polylines?

I would think that there should be multiple columns of curves, about the same as the row curves.

Are you trying to network ribbons, or a grid?

A reduced size demo "3dm" would be nice to see?

- Brian

I think Network works on a grid, "quad-ish", like a very wavy screen door screen.
- B

You would need to do a second data set in column format?

Thanks for the suggestions Brian. I'll try that.
Maybe if I make a surface for each of the smaller units and remove the polylines, I can then join the surfaces up with a smaller hit on memory/processor.

Maybe Loft?
Networks seems better way?
- B

Let P be a matrix of points. Just the raw point.z values need be stored. ( Pt.z ).
The row numbers are the x coordinates (possibly scaled a bit).
(Or store all the raw point data, Pt, with Pt containing (Pt.x, Pt.y, Pt.z))
The column numbers are the y coordinates (possibly scaled a bit).
P is a javascript array of arrays, and is zero indexed.
P[i][j] = P[row][col] is of dimension 2,400 by 2,400 = 5,760,000 z values.
The entries of P can be accessed by row, or by column, to create the curves.

If there is too much data, smaller chunks of P could be accessed, either n rows, with all columns,
or vice versa, or rectangular subsets of the matrix could be accesed.

Well, a few thoughts anyway.

- Brian

I wonder if the surface edges/ surface results of network chunks join up the same as the surface result of a complete network?
And what are the geometry data limits of MoI4?

Mmmm, good point Brian. Will have to experiment to see if the chunks will join along their edges.

I've created a much reduced data set with just 20 curves for testing (attached).
I also include 2 images to show the resulting model before and after the surface has been applied. All works very well, although the network operation takes time even with this many curves.

And here is the modified script I used to load the multiple curves. It was a quick job and I've only tested it with Polylines!

Here is the 3dm file for the model before I remove the polylines from the surface.

And here is the final surface with a basic road aligned above it, ready for projection.

Trouble is, I can't get it to project onto the surface for some reason. I've used projection before without issue.

Any ideas please? Thanks!

Seems your object is out scale of the Origin !
Default Grid is 300 * 300
Your object is 123 600 * 2 000

Sorry, don't know what that means! I have used the longitude for the Y axis so yes, the values are large but I don't think that makes much difference to the result.

All the axis are scaled correctly in cm.

Just tried the same projection operation with MOI 3.0 and it worked fine. Must be an issue with the beta version.

You right!