[Qgis-user] vector point grid to raster grid -- pixel size does not work

[chris hermansen]

María and list

On Thu, May 14, 2020, 00:46 Priv.-Doz. Dr. Maria Shinoto <
maria.shinoto at zaw.uni-heidelberg.de> wrote:

> Chris,
>
> Thank you for your ideas. I am trying now, but there are some questions:
>
> > For this, rather than use the Raster > Rasterize tool, the approach
> should be:
> >       • open the processing toolbox Processing > Toolbox
> >       • in the toolbox open Interpolation > TIN interpolation
>
> OK until this point
>
>
> >       • in the TIN Interpolation screen:
> >               • select the Vector layer
>
> OK.
>
> >               • select the Interpolation attribute
>
> First problem: I stored the vector layer in a Geopackage; so I have an fid
> from the geopackage database, an ID from the original xyz-File in field_1,
> and the x, y, z values in field_2, _3 and _4.
>
> Which attribute should I choose?  I think only field_2 and field_3?
>

No you just want the elevation field here I guess it's your _4?

>
> There is a checkbox for the Z-coordinate, whether I with to use it for
> interpolation. I guess I leave unchecked?
>

Yes

>
> >               • click the + to add to the vector layer panel
>
> So I added the two fields, they are "Points"
>

Just the one field

>
> >               • choose the interpolation method - probably best to use
> cubic
> >               • click on the ... next to extent and set it to the layer
> extent
>
> OK
>
> >               • set the pixel size to 5.0 and 5.0
>
> OK
>
> >               • click Run
>
> OK
>
> > This way you won't have the odd sizes you mentioned.  This may give you
> a smoother surface in the end as well.
>
> I started the prozess, but with more than 11 Million points, it seems to
> take too long, I am stuck at 50%. Will try later again.
>

You can always try IDW instead of TIN.

Chris
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