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BjornNyberg / Geometric-Attributes-Toolbox

The Geometric Attributes toolbox is a set of QGIS tools designed for the geometric attribute and shape characterization of modern depositional elements
GNU General Public License v3.0
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Centerlines output error #9

Closed limw10 closed 3 years ago

limw10 commented 3 years ago

Road Centerlines

Hi there, i have tried the functionality of the plugin in QGIS on my road polygon layer but it doesnt seem to be generating all the centerlines. I have buffered the polygon to -0.1 as recommended to avoid any over lap and test with various line spacing parameters but still end up with an incomplete centerlines. see images for reference. Your assistance will be greatly appreciated!

limw10 commented 3 years ago

Centerlines2 Hi again, just following up, I adjusted the parameters for Densify Vertex Spacing, the results is better but still i am not getting the complete centerlines. Thanks

BjornNyberg commented 3 years ago

@linw10 Did you solve the problem? I would be able to help more if I could recieve a sample dataset to test in order to reproduce the problem. Nonetheless I can see that you need to use a trim iterations option rather than "All". All option will define all centerlines from one startpoint to one endpoint. Whereas trim iterations will be able to find multiple endpoints.

BjornNyberg commented 3 years ago

As an example take a look at this road network from London for clarification. This dataset is from OSM and contains one dissolve polygon representing roads. In this example trim iterations were set at 10 but will vary depending on the complexity of your polygon (i.e. how many vertices will define a new branch).

Centerlines All Trim

limw10 commented 3 years ago

@BjornNyberg , thanks for the illustration over here, it helps alot. I got the plugin work out in the end. There is no issues with it. Thanks alot and a great plugin tool!