Surface from X/Y/Z Points.

I need create a surface ( Terrain ) from a list of coordinates in XYZ format.

The list is something like...

PointNum, Description, X, Z, Y

4,TEST,22.950,-16.758,199.995
5,TEST,-75.044,19.454,199.461
6,TEST,51.060,-21.960,200.930
7,TEST,-88.051,44.489,199.229
...

Read the file and put the points in the 3D is easy, but... i dont have experience in surfaces... i try to make it... but, i can't.

If anyone have a idea or example to make it, please help me. =)

Is this your own terrain mesh? Or are you using Blitz's terrain commands? If so why don't you make a gradient map from your surface info instead? 0-256 colour grey scale. Save it out and then then just load it in using the load terrain command - means you don't have to mess about with surfaces.

eee... yep, is an option, but... i need generate the heightmap first.

And i not sure wich option is more complex... create a surface or generate a heighmap from the XYZ file.

Suggest making another heightmap.

A heightmap assumes uniform spacing in the x/z axis which is why you only need to store the y component.

The data above is all over the place with strange coords ( 199.995 ?? ). It's definately not uniform in terms of x/z coords so it would probably be difficult to convert to an image.

How much more data do you have? I could try something for you. I'm off work atm - just had a toe nail removed ( ouch ) so have time on my hands.

Stevie

Where are you getting all this terrain data from anyway? It sounds a bit long-winded when you could just airbrush some heightmaps in a paint program instead.

@Stevie
The file contain around 487 points...
If you need see the file, Here is http://www.badmouse.cl/download/xyz.txt

I update the first post, the format of the file is X,Z,Y... sorry for the mistake.

Thx for your time.

Ok, leave it with me.

See attached plot of X & Z coords.



They are too random so there is no chance of making a mesh out of them or a heightmap. The Y coord doesn't fluctuate much anyway, it's between 180-200. Do you really need to use this naff data? What are you trying to do? Suggest you start from scratch using a heightmap as Hujiklo mentioned.

Stevie

The data is from a topographic intrument.
In the image, you can see the area of a real terrain.

I try to make in a easy way the process of create a preview in 3D, without the complex process in the case of others software like "Autocad Survey".

Hmm, you'd need to use some form of tesselation routine which I'm guessing is the reason some most would use "AutoCad Survey".

It's extremely complicated to build a mesh from a bunch of random points but there is alot of stuff on google e.g.

http://www.cs.berkeley.edu/~ug/slide/docs/slide/spec/spec_frame_meshnode.shtml

I had this exact same issue the other day in writing code to produce a cartogram (in this case a mesh from points distorted by travel times).

I didn't get very far - in the end went with manually selecting the points (with which to create the polys) and saving the resultant mesh plus point selection order to file.

However I didn't have as many points to tesselate as you do...

@Stevie
Anyway, thx for your time Stevie.
I have some ideas now, maybe i can do it...

@MadJack
Please, you can post some example from your code?.

Tab

Sorry - not for a couple of days - it's the weekend here in NZ and the code's on my work PC.

But it wasn't that extensive - basically pick three points, create a polygon - the code's all available from the archives here on this site.