Boundary of a Set of Points.

This tool allows you to search a contour englobing a set of points. The program asks you to select the points and then computes the contour (a 3D Polyline). You can refine the contour afterwards by entering a maximal length for the segments. The program will search again for a new contour that complies with that constraint. If a segment cannot be modified in order to comply with the constraint, the program will stop. The option "Ignore segments that are too long if necessary" will allow you to continue the process even if some segments cannot be modified to comply with the length constraint. Once the contour has been created, you can use it as a frontier to the triangulation.

Entity Types

• Select the entities to use as points : indicate what type of entities represent the points. In general, they are Autocad POINT entities, but you can also use BLOCK entities (usually, a block contains the point and the attributes Number and Altitude). In this case, the insertion point of the block will be used as coordinates.
• Points : Check this option to use POINT entities.
• Blocks : Check this option to use BLOCK entities.

Boundary Creation

• Layer : Enter the name of the layer in which the contour will be created, or click on to choose from a list .
• Ignore the segments that are too long if necessary : Check this option to continue the processing even if some segments cannot be modified to comply with the length constraint. The program will then display on the command line the number of unmodified segments. Warning: In this case, some points may end up outside the contour.

Adjust the parameters of the dialog box, then click on "OK". FlashMNT then displays the command line :

>> Select the objects :

Select the desired point objects then validate. FlashMNT searches the first convex contour, then displays the command line :

>> [ENTER] to keep this contour or enter the new distance <30.000> :

Enter then the new maximal length of the contour segments, or validate to preserve the current contour.

Initial contour

Contour with length = 20

Remarks : Used on a large number of points, this command can be relatively slow.