Concave Hull
#updated
Purpose
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The tool is provided for building concave hulls for features of any geometry type (points, polylines, and polygons).
The concave hull is built for the input features in such a way that all their points/nodes are included to the hull. The concave hull shape depends on the input data type and the level of detail. Besides, there is an option to create multiple hulls. To do so, the fields defining the group for each hull need to be specified.
As a result, a new polygon layer will be created.
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Input features |
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Concave hull |
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Customizing the hull
Single and multiple concave hulls
The tool allows creating both single and multiple hulls. If you want to create the single concave hull, leave the «Group by Fields» section empty. In this case one concave hull for all the input features will be created.
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Geometry |
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In order to create multiple concave hulls, you need to specify the grouping fields. In this case, for each found group the separate concave hull will be created. The fields used for grouping will be added to the output dataset along with multiple concave hulls.
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Geometry |
Attributes |
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Level of detail
The concavity level depends on the level of detail varying from 0% to 100%. The level of detail 0% means that the hull shape is close to convex hull, but may still not fully coincide with it. With the detail value 100% the empty areas inside the hull will be excluded as much as possible, but they may reside because of the high density of the input points or in cases when boundaries of the input polylines and polygons build a barrier for the concave hull.
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0% |
45% |
90% |
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Allow holes
In some cases, it may be needed to allow holes in the created concave hulls. For instance, the input features are located in such a way that there may be empty spaces within the output hulls. In such cases creating holes allows excluding such empty spaces from hulls for more detailed shapes.
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Input features |
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Concave hull |
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