Save individual observer rasters

[sohosys]

Thank you very much for this plugin!

in the .5 version with QGIS 2 it is possible to save each observer point viewshed raster individually, or the cumulative output viewshed raster. Is it possible to do the same with .6 in QGIS 3, or is the cumulative option the only one in .6?

If not, is there a method to run a batch/loop in QGIS to loop through each observer point and run the viewshed individually?

[zoran-cuckovic]

Hello,
I've removed the option of registering individual files in the QGIS 3 version. More often than not, the individual output is a result of user overlook...

In QGIS 3 you can use the "run as batch process" option to achieve what you need, but it's not handy for larger numbers of points.

Why do you need multiple individual outputs? If there is a general need for such a feature, I could perhaps schedule it for next release (no promises).

[stephenjarvis]

I would also like this functionality if it is easy to add back in.

Otherwise I'm going to figure out how to write a script that loads a DEM and Points layer (with many points) and then iterates over each point in the Points layer to do the following:

1. Crop DEM to fit chosen Radius around the selected point
2. Calculate binary viewshed (or depth-below-horizion) for the selected point using the cropped DEM
3. Save and repeat for each point in Points

To give you a sense of the use case I have in mind, this is for some work looking at the visibility of wind turbines. Different wind projects come online at different times so just having a cumulative visibility value isn't very useful. I actually want to be able to separately identify the visibility of each turbine to account for the fact that some became visible before others. I imagine you could think of doing a similar kind of analysis for anything where visibility changes over time (e.g. building construction, deforestation etc. etc.)

[zoran-cuckovic]

Hello,
If you don't have 100s of points, you can use QGIS batch processing (all algorithms can be run in the batch mode). You will only need to split your points into individual files, to feed the batch. see for splitting on StackExchange

[stephenjarvis]

Thanks for the tip.

In the meantime I've managed to use the intervisibility algorithm to achieve what I wanted in one go because I already have both the target points (~2000 wind projects) and observer points (~2.4 million postcodes).

If at some point in the future I actually need the full visibility rasters for each target point then I'll give the batch processing a go.

Thanks again, this is a great package! :)