Model Creation in n4ce
Models in n4ce are used to generate Contours, Sections, Volumes and view surfaces in 3D. A modified Delauney algorithm is used, where coded points and features strings are linked together to form a network of non-overlapping triangles. We call this a digital terrain model (DTM). Elsewhere, these may be referred to as digital ground model (DGM) or triangular integrated network (TIN).
The menu bar contains access to tools for handling Points, Features, DTMs, Contours, and Sections. Additional Icon Bars provide for Zooming, Query and access to the 3D Viewer.
Tools within the View menu allow you to create your own customised Icon bars.
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The DTM is created from points stored in XYZ with a feature code. The Feature Code is used to identify points to be included in the DTM. This can be supplemented with comma codes ,X or ,Y to eliminate individual points from the DTM. Further, since coded point can be allocated their own layer, only points turned on will be considered. If line features can be assigned as Break Lines.
During DTM creation, various checks and reports are made on the consistence of data, for duplicate points and crossing constraints.
Infilled triangles are called Groups and are used in Area and Volume calculations. Tools are provided for adding and deleting these groups. |
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Even though you may have applied all the checks available there may still be problems with your DTM. This may be a localised high/low point or places where triangles form unwanted creases in the DTM.
You may also wish to manually Switch, Insert or Delete triangles. Tools are available for this purpose, as shown in the above DTM Edit menu. |
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One way of showing elevation detail is via contours, but of course, it takes skill to visualise highs and lows. A far better way is to show 3D perspectives with solid fills, wire frame with or without contours superimposed.
Once a DTM has been created simply select the cube icon and you will se a 3D image of the model. Various options are available for showing contours, wire frame, groups and height shaded models. | The 3D model is particularly helpful when editing the DTM since ripple through effects show detail changes in both views. You will note that twin views have been shown here, an OGL and finished surfaces. |
