gdalbuildvrt - setting scale dependent visibility

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gdalbuildvrt - setting scale dependent visibility

Graham
Hi,

When using gdalbuildvrt to create a virtual raster, is there a way to specify the scale dependent visibility of the vrt that is being created?
My reason for this question is that when displaying a vrt containing a large number of rasters QGIS 2.0.1 takes a very long time to open up the Layer Properties dialogue.  It would be therefore be a useful timesaver to set the visibility using the gdalbuildvrt command.
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Re: gdalbuildvrt - setting scale dependent visibility

Alexandre Neto
Graham,

You need to create the overlays (pyramids) for the virtual raster.

You can do it directly in QGIS:
 - Turn render off;
 - Load the Virtual raster;
 - Open Layer properties (right-click) and go to Pyramids
 - Select all the resolutions proposed and press Build pyramids.

Or you can do it using GDAL in the terminal or comand line.

 Have a look here:


there is also a great tutorial\testing in Portuguese, maybe you can understand it using a automatically translated version:


Hope this helps.

Alexandre Neto



On Thu, Dec 19, 2013 at 11:06 AM, Graham <[hidden email]> wrote:
Hi,

When using gdalbuildvrt to create a virtual raster, is there a way to
specify the scale dependent visibility of the vrt that is being created?
My reason for this question is that when displaying a vrt containing a large
number of rasters QGIS 2.0.1 takes a very long time to open up the Layer
Properties dialogue.  It would be therefore be a useful timesaver to set the
visibility using the gdalbuildvrt command.



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