I´d like to reproduce the smoothing operations done with the Generalizer Plugin inside the v.generalizer Toolbox so I can use them on a polygon layer instead of only on a line layer.

I tried different values for different settings but I just don't see how to get the same results using the v.generalizer algorithm in the Processing toolbar.

To which values in the v.generalizer algorithm window do the settings I see in the generalizer plugin correspond to?

Here are the settings I´d like to use and the results I get:

  1. Hermite

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  2. Chaikin

    enter image description here

Now in the v.generalize windows, there are so many options and values but nothing there is named the same as the ones in the generalizer plugin…

I tried using the v.generalizer toolbox after reading these two questions:

I'm using QGIS 2.4.


1 Answer 1


There is a difference in wording, but I think the options from the Generalizer plugin exists in the v.generalizer interface. Using Google Translate (yes, not the best thing to use) for the Generalizer Homepage, we can find a description on each algorithms used and their corresponding parameters.

In terms of Hermite Spline Interpolation, the homepage tells us:

Threshold - Determines the distance between the created points.

Thightness - Factor determining the degree of bending of the resulting line. 

Now looking at the Help section in v.generalizer, we can try and find those parameters mentioned above. For Threshold:

Maximal tolerance value <------ This is in the options.
Options: 0-1000000000

For Thightness:

Minimum angle between two consecutive segments in Hermite method <--- This is in the options.


In terms of Chaiken's Algorithm, the homepage tells us:

Level - Determines the number of iterations of the algorithm.

Weight - Determines the shear rate, the bigger the fillets are closer to the line of nodes. 

Now we look at the Help section in v.generalizer again. For Level:

Number of iterations <----- This is in the options.

For Weight:

betweeness_thresh - It denotes to what extent a line is in between the other lines in the network (unsure if this is the correct parameter!)



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