New Model by Approximate OffsetNew Model by Approximate Offset

(This functionality is available with the Modelling module)
(Not available in LISCAD Lite)

Creates new points and a model at an approximate offset to a currenty available model. This command is available from the Edit/New Model menu in the Terrain Modelling Task.

New Model by Approximate Offset dialog box

Item Used to
Current Model Name Select the model from which the offset is to be applied to obtain the new model.
New Model Name Enter the new name for the model to be created
Offset Enter the Offset from the existing model to the new model (positive for new model above the current model).
Starting Point Identifier Enter the starting point identifier for the new points to be created. The starting point identifier may also be determined by using the Next or Last buttons.
Point Code Select the check box and a code from the list if you want the new points created on that particular code with its attributes as per the code table. If the check box is not active, the new points will have the same codes and attributes as the original points.
Minimum Area of triangles Ignore corrections to the vertical distance for triangles less than the entered area. (Refer to methodology explained below).
Apply Create the new points and model at the approximate offet to the model.


The resulting model will not be exactly parallel to the current model. The methodology (explained below) is aimed at obtaining a model that is approximately at the desired offset.

For each triangle at a current model point, a vertical distance is computed as the entered offset corrected for the triangle slope. The offset is used as the vertical distance i.e. (no correction is applied) for triangles less than the minimum area entered.

Each of these distances is weighted according to its triagle area and a weighted average distance for all the triangles at the point computed. That weighted average distance is then applied vertically to obtain the new model point. The distance will be different at each point and always larger than the offset.