Failure to create TIN from countour data.

[OrhanGUNDUZ]

Hi guys:

I have a bunch of countour tiles (154 to be exact) with a total of about 440000 objects that I want to create TIN from. 3DAnalyst reports the following error and stops execution:

Failed to add features from contours

Attempt made to access an empty object
Failure to create TIN.

Any ideas why that might happen.

Thanks.

OG

Platform: ArcGIS 9.3.1 running on a Win7 machine.

[EricRice]

Greetings,

TIN's have a physical limit of ~15 million data nodes. If you build a TIN with just one tile of contours, and check the properties of the TIN, how many data nodes does it have? This should help you somewhat estimate the total node count of all contour tiles. You're most likely way over 15 million since every vertice in the contour is considered a node. Ideally, you should only put 4 or 5 million data nodes in a TIN for performance reasons. You should consider building a Geodatabase terrain dataset.

What is a terrain dataset?
(Terrains exist in 9.3.1 even though this is the 10.1 help link)

Best,
Eric

[OrhanGUNDUZ]

Dear Eric:

Thanks for the info. I did indeed have approx. 29 million data points. I succeeded to create a TIN from a file geodatabase. But I eventually have to get this terrain saved as a raster grid where I could do some map calculations. Is it possible to convert and save this TIN to a raster?

Thanks,

Orhan Gunduz

[EricRice]

See TIN to Raster or Terrain to Raster tools.

Eric

[OrhanGUNDUZ]

Eric:

Thanks for the info. I was aware of the TIN to raster command but that did not work in 9.3 (probably due to size limitations). It worked flawlessly in 10.1.

Cheers,

Orhan

[JakubSisak]

TIN created from countours will be extremely complex.  You can greatly improve performance by generalizing the TIN. (Terrain and TIN Surface -> Decimate TIN Nodes) This will produce a generalized version of the input TIN based on parameters you specify. (ie Z Tolerance or maximum number of nodes)