Question

TIN Generator fatal error: NAN values

  • 8 August 2018
  • 1 reply
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I'm using the TINGenerator-transformer to calculate slope and aspect for triangles. This works most of the time, but I sometimes get the following error:

Surface Model cannot be constructed. Either all points are linear or initial set of points did not consist of 3 non NAN elevations.

I've attached a workbench which creates such a geometry. The points are not linear nor do they consist of NAN elevations...

If there is a better way to calculate slope and aspect for geometries, then I would of course be more than happy to use that approach instead...


1 reply

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@broens

Looks like the polygon is very small and too long in relation to its width. (unless you big units.)

The Generator cannot turn it into on triangle.

Use a densifier. Your object has a length of approximately 1.5 (unknown units)

and max width of +/- 0.0028 unknown units.

You can set the densifier to exact interval.

Then the generator can turn it into triangles.

Though to get the exact tin that exactly covers the input polygon seems to me trial and error if at all possible.

With exact interval at 0.02 you get very close, but it will not cover 100%. This will yield 282 triangles though!

I tested this

You are better of treating this object as an error.

Either get rid of it or repair the input data.

Or process it before using the tin generator.

Maybe it is a overlap (bad drawing)

Or maybe it belongs to an adjacent polygon?

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