REMOSCAPE EXPORTED 3D TILES LANDSCAPE

This is a 3D landscape from Remoscape, exported to the 3D Tiles format.

3D Tiles is a format created and supported by the Cesium geospatial platform. The format has become
an OGC (Open Geospatial Consortium) standard and it is supported in for example CesiumJS,
Unreal Engine, Unity, VulkanSceneGraph and Carmenta.

The zip file can be uploaded directly to Cesium ion, or if you have already unzipped it, just zip it
again. Then select the zip file in Cesium ion, set "What kind of data is this?" to "3D Tiles" and
"Main JSON File" to <Name>_3D_Tiles/tileset.json.

You can use the code provided in cesium.js in Cesium Sandcastle to clip the Cesium terrain around
your landscape and place the camera for an overview of your landscape. Refer to the comments in
cesium.js for how to modify the script with your access token and asset ID. You can reach Cesium
Sandcastle from the "Open complete code example" in Cesium ion.

The center.txt file contains the landscape's center position given as longitude, latitude in WGS84
decimal degrees and elevation in meters. Just like the Vertical Datum export setting, the definition
of the elevation here also depends on if the elevation from raster or laser was defined as height
above the WGS84 ellipsoid or above the EGM84, EGM96 or EGM2008 geoid. You can see what was decided
at export as export_vertical_datum in the included Remoscape_export.json file.

To use the 3D Tiles export in Unreal Engine, first download and install the Cesium for Unreal plugin
from the UE Marketplace and follow the instructions and learn the basics from the Cesium for Unreal
learning center. Then unzip the downloaded export in a suitable folder, create a
"Blank 3D Tiles Tileset" in your Cesium for Unreal project, set its "Source" to "From URL" and set
the URL to a file URL pointing to your tileset file, for example:
file:///C:/Users/yourname/Downloads/<Name>_3D_Tiles/tileset.json

Set the Origin Latitude and Origin Longitude in the CesiumGeoreference component in Unreal Engine
to the position from the center.txt file. Set Origin Height to a desired height in meters above the
elevation given in center.txt. Also, you might want to decrease the Light Intensity value in the
DirectionalLight item in the CesiumSunSky component to something like 1.0 lux.

There is a file called unreal_engine_cartographic_polygon.txt included with the export. It contains
a cartographic polygon that can be used in Unreal Engine to cut out the surrounding terrain, for
example the Cesium globe, and avoid overlapping and flickering terrain in your exported landscape
area. Open unreal_engine_cartographic_polygon.txt in a text editor, copy all text and paste it in
the Outliner panel in Unreal Engine.

If you experience strange flickering in Unreal Engine, this is a known issue with certain versions
of the Cesium for Unreal plugin and can be fixed by enabling Render CustomDepth Pass on the tileset
under Rendering -> Advanced.

To use the 3D Tiles export in Unity, first install and start using the Cesium for Unity plugin by
following the Cesium for Unity Quickstart on the Cesium website, if you have not already. Then add a
Blank 3D Tileset, set its Tileset Source to From URL and set the URL to a local path to your tileset,
for example C:/Users/yourname/Downloads/<Name>_3D_Tiles/tileset.json

The same adjustments in CesiumGeoreference as recommended for Unreal Engine above apply in Unity
as well. Also set the Position in the DynamicCamera component to the same latitude, longitude and
height.
