TIN Surfaces


In addition to using them to contour or grid areas from data samples, TINs (Triangulated Irregular Networks) can also be used to create 3d surfaces.

The following example uses elevation data for the 20km SH64 square in Snowdonia (North Wales). The data was stored in the archaic NTF format and converted to CSV, before being imported into Maptitude as a conventional point layer. The point layer has been set to draw each point and color it from green (low elevation) to orange (high elevation). The general effect appears to tile the map surface:

The height data loaded as a conventional point layer. The road layer has also been included in order to provide a visual reference point.

As before, a TIN is created using the Surface Analysis dialog box.

We can create the surface straight away, but Maptitude surfaces are more reliable if they are created from a Gridded Layer. Grid your TIN by pressing the Grid button (3×3 grid, second button from the right, disabled in the image below) on the Surface Analysis Toolbox:

Surface Analysis Toolbox

Next, to create the surface we should select the source layer as the current working layer. This should either be the original TIN, or ideally the new gridded layer. We zoom to the required part of the layer, and create the surface by pressing the Surface (green cube) button on the Surface Analysis Toolbox (see above).

See Creating a Surface for the details about surface creation and the options that are available.

This is what the resulting surface looks like:

The surface created from a TIN, which in turn was created from an imported CSV file of elevation data. The Mynydd Mawr massif is in the foreground, with Blaenau Ffestiniog to the east of it. Click for larger view.

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