[GRASS-user] Densify vertices in polygon

[Markus Metz]

Hi Robert,

On Wed, Jun 19, 2019 at 4:26 PM Robert Nuske <rsn.mailinglists at gmail.com>
wrote:
>
> Dear Listers,
>
> I would like to smooth polygons coming from a raster via r.to.vect using
> v.generalize methods=snakes.
>
> If I understood the documentation correctly, snakes is the only method
> that tries to go the middle ground: neither entirely circumscribing
> (larger than original polygon) nor inscribing (smaller than original
> polygon) the polygon. I love that behavior. But snakes only works with
> the available vertices and does not generate new vertices => quite rough
> outlines.
>
> So i thought it would be a good idea to densify the vertices of the
> polygon before the generalization. Create new vertices with distance x
> on the boundary of the polygon. But couldn't find a function in GRASS
> doing that.

v.split -n should do exactly this: add new vertices with distance x:
length=x
The -n flag causes new vertices to be added with splitting the
lines/boundaries.

>
> I would love any hints on generalization in general and on how to
> densify my vertices.

Apart from the manual of v.generalize, there is a tutorial at
https://grasswiki.osgeo.org/wiki/V.generalize_tutorial
(maybe not completely up to date)

HTH,

Markus M
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20190619/4f32b3c9/attachment.html>