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Managing black area from an mTransformer 3D map tile output

by Technical Evangelist on ‎12-05-2016 07:15 AM - edited on ‎04-13-2017 05:42 AM by Technical Evangelist (425 Views)

Question

When a user outputs a 3D map tile from mTransformer there can often be a 'black' area buffering the output map tile should that tile not 'fill' the bbox specified during tile generation. How can this 'black' area be managed in mTransformer so that it doesn't show as 'black' area when the 3D map tile is viewed in a Geospatial Portal instance?

Answer

Black and/or white areas appearing in the BBox of 3D Tiles are areas of ‘no data’. If there is no data in the input there will be none in the output.

There is only so much that can be done for these areas in a 3D tile.

 

They can be set a certain value directly on the dataset in mTransformer by adding option using a value of user choice (0/255 being most popular).

 

<option name="default-nodata-value">0</option>

 

Secondly (and more visibly pleaseing) a backdrop can be used such as BlueMarble to fill/merge the ‘no data’ areas.

Using file from http://geodata.myvr.net/BlueMarble_NextGeneration/june/gtiff/ it would look similar to this for an example

<OrthoDictionary>

        <input id="0">

            <option name="default-nodata-value">255</option>

            <option name="input-path">D:\Data\Ortho\ortho.tif</option>

            <option name="default-input-EPSG">21781</option>

            <option name="force-EPSG">true</option>

            <option name="include-bbox">true</option>

            <option name="wip-path">D:\Data \Tiles\output\wip\OrthoDictionary\</option>

        </input>

            <input id="1">

            <option name="input-path">D:\3D-Data\BlueMarble</option>

            <option name="default-input-EPSG">4326</option>

            <option name="force-EPSG">false</option>

            <option name="include-bbox">false</option>

            <option name="wip-path"> D:\Data \Tiles\output\wip\OrthoDictionary\</option>

        </input>

</OrthoDictionary>

 

 

These configuration elements are explained in more detail in the Appendix B of the mTransformer User Guide.

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