Grant-in-Aid for Scientific Research on Innovative Areas 5101 in FY2019 (19H05732)

Visualization software for archaeological remains and background celestial bodies

Terrain Generation QGIS Plugin for arcAstroVR「terrain for arcAstroVR」
Ver.0.2
12/22/2022

Table of Contents
Change log....................................................................................................................................................2
1.Overview....................................................................................................................................................3
2. Install..........................................................................................................................................................3
2-1. Installing QGIS.....................................................................................................................................3
2-2. Installing the Plugin.............................................................................................................................4
3.GIS (Geographic Information System) Basics............................................................................................5
3-1. Data types and layers...........................................................................................................................5
3-2. Ellipsoidal height, geoid, and elevation...............................................................................................6
3-3. Projection Method...............................................................................................................................7
4. arcAstroVR terrain format.........................................................................................................................7
5. Creating Terrain for arcAstroVR..............................................................................................................8
5-1. Creating a Texture Layer.....................................................................................................................8
5-2. Creating an elevation layer .................................................................................................................9
5-2-1 Prepareing elevation data.............................................................................................................................9
JAXA: ALOS World 3D - 30m (AW3D30)...................................................................................................10
METIof Japan/NASA: ASTER Global 3D Topographic Data......................................................................10
GSI of Japan: Basic Map Information Digital Elevation Model DEM5A......................................................11
5-2-2. Registering and merging GeoTiff files............................................................................................13
5-3. Creating a geoid layer..........................................................................................................................15
5-4. Creating a Mask Layer........................................................................................................................16
5-5. Output of terrain data for arcAstroVR using Plugin..........................................................................17
5-6. Creating a dataset for arcAstroVR......................................................................................................20
Contact...........................................................................................................................................................21

Change Log
App

更新内容

Updated date

0.1.2

2022 Mar. 1

First Draft

0.2

2022 Dec. 22

addition・Supports multiple languages (Japanese, English, Spanish)・Added a function to display in orthographic projection centered on latitude and longitude coordinates
when latitude and longitude are entered・Added a function to display wide-area terrain areas in red lines centered on the set latitude andlongitude
・Added a function to display narrow-area terrain areas in green lines when narrow-area terrain is set
modification
・When there is nodata in a narrow area, correction for overlapping of wide area terrain in the same placeis not performed.

1. Overview
This software is a plugin for creating terrain data for arcAstroVR using QGIS. QGIS is a free and open
geographic information system (GIS) that can automatically adjust the position and size of map files invarious formats and convert them into various projections for display. By loading your own elevation dataand image data into QGIS, you can create the following four types of data required for arcAstroVR.
・Wide-area topographical data of 300km square（terrain11.raw〜terrain33.raw）
・Small area terrain data of any resolution and size（terrain00.raw）

・Texture for wide area terrain data（terrain11.jpg〜terrain33.jpg）
・Texture for narrow area terrain data（terrain00.jpg）
The basic workflow is to prepare the following five layers in QGIS, then specify and run the above layers inthis plugin to create terrain data for arcAstroVR.
・Elevation raster layer (300km square, 30m resolution)
・Elevation raster layer with resolution of 0.1 to 10 m
・Elevation raster layer for geoid
・Raster layer for textures
・Mask vector layer for altitude adjustment

2. Install
2-1. Installing QGISQGIS is available for Windows, Mac, and Linux and can be downloaded from the following URL.

https://qgis.org/ja/site/forusers/download.html
This plugin is compatible with QGIS Ver. 3 and above. If you are using Ver. 2 or earlier, please download
and use the latest version.
When you run the QGIS installer, theinstallation will proceed as follows:
3-Agree to the terms and conditions
4-Specify the installation destination
5-Select the components to install

At this point, you can proceed with all
the defaults, such as "OK" and "Next".
Once the installation is complete, start QGIS
and you will see the screen on the right.

2-2. Installing the Plugin
Install this plugin software into QGIS.
From the QGIS menu, select "Plugins > Manage and installplugins".

In the plugin dialog that appears, select "Install from ZIP."Drag and drop the software file "terrain4aAVR.zip" into the ZIP file input field and set the location of theinstallation file. (You can also select the file from the button to the right of the input field.)

Press the "Install" button to begin the installation.
When "Installation complete" is displayed, press the "Close" button at the bottom right to close the dialog.
If the Terrain for arcAstroVR icon is displayed second from the right on the second row of the QGIS iconbar, the installation of this plugin software was successful.

3. GIS (Geographic Information System) Basics
3-1. Data types and layers
GIS is a system for handling various topographical data, and the most well-known free software is QGIS,
while the paid software is ArcGIS. GIS handles roughly three types of data types.
Raster Data

This refers to image data in which pixels are arranged vertically and horizontally. When enlarged,
the pixels become larger and jagged edges appear. Elevation data is often of this type, and image
formats such as jpg, gif, and tif are generally used.

Vector data

This refers to data that consists of coordinates. Lines, surfaces, etc. are expressed as connections
between coordinates, so the display is smooth even when enlarged. Geographical feature data is often
of this type, and vector formats such as shp are generally used.

XYZ Tile Data

It is a type of raster data, but like Google Maps, it collects and connects tiled images according to thezoom ratio and location to display them. Map data is often of this type, and URLs are generally used.

In QGIS, the maps you display
are managed using layers.
When you register raster data,
vector data, or XYZ tile data in
the layer column on the left sideof QGIS, the geographic
information system adjusts the
position, size, and projection
method, and displays them inthe order of layers on the main
screen. In addition, you canadjust the transparency (rightclick on the layer > Properties >Transparency) and blending
method (right-click on the layer> Properties > Symbology) for
each layer, so you can overwrite
them in various ways.

©️G o o g le Ma p s / Go o g le Ea e rth

3-2. Ellipsoidal height, geoid, and elevation
The Earth has an ellipsoidal shape and is represented by an ellipsoidal model called WGS84. However, an altitude of
0m does not necessarily coincide with the surface of the ellipsoid. The definition of an altitude of 0m indicates themean sea level when the Earth's surface is filled with seawater, and due to regional gravity bias, there is a difference ofapproximately -67m to +79m between an altitude of 0m and the WGS84 ellipsoid. This difference is called the geoid
height, and the surface that coincides with an altitude of 0m is called the geoid. The sum of the geoid height andaltitude is called the ellipsoidal height, and it corresponds to the height of the terrain from the WGS84 ellipsoid.

Publicly available terrain data is elevation data that
does not include elevation changes due to geoid
fluctuations, so when trying to accurately reproduce
terrain in VR space, it is essential to supplement thegeoid height data. arcAstroVR uses ellipsoidal heightterrain data that adds geoid height to elevation.

3-3. Projection Method

The Mercator and Miller projections, which are often used for maps and elevation data, are expressed in arectangular coordinate system in which meridians and latitudes intersect at right angles, and are characterized by large
distortion, with distances and areas expanding as one approaches the poles.
On the other hand, an orthographic projection shows the exact shape of the surrounding area centered on an
observation point. Therefore, to create terrain data for arcAstroVR, elevation data is converted to an orthographic
projection. In addition, the ground descent in the height direction is calculated to follow the curvature of the sphere,
and the terrain on the Earth ellipsoid is reproduced.

4. arcAstroVR terrain format

Elevation data is often provided in rectangular coordinates, where meridians and parallels intersect at right angles,
and if this is directly deployed in a VR space, it will result in a flat world that continues to infinity.
To reproduce the actual terrain, it is necessary to perform orthorectification, deformation of the terrain to conformto the curvature of the Earth, spherical correction, and optical correction using the equivalent Earth radius that takes
into account the effect of the atmosphere, which makes it possible to see far away.

These corrected terrain data are used for arcAstroVR terrain.arcAstroVR.

©JAXA AW3D30©JAXA AW3D30

5. Creating terrain for arcAstroVR

The creation of terrain for arcAstroVR starts with creating layers of various terrain data. If you alreadyhave various data and have created layers, you can skip to "5-5. Output of terrain data for arcAstroVR using
Plugin".

5-1. Creating a Texture Layer
Satellite photos and maps to be pasted onto theSatellite photos and maps to be pasted onto thearcAstroVR terrain are registered and displayed in
QGIS.
We recommend using the XYZ tile format (see 3-1
Data Types) for this, as it displays raster images withthe appropriate resolution depending on the zoom
level. Here we will create a texture layer using asatellite image from Google Maps as an example.

1. Click XYZ Tiles in the browser on the left side of
QGIS and select "New Connection...".

2. In the XYZ connection dialog, enter "GoogleMaps(Satellite Photos)" in the name field, enter"http://mt1.google.com/vt/lyrs=s&x={x}&y={y}&z={z}&s=Ga" in the URL field, and click the "OK" button.
3. A newly registered XYZ connection "GoogleMaps (Satellite Photos)" is added under "XYZ Tiles" in thebrowser field. If you double-click this "GoogleMaps (Satellite Photos)", "GoogleMaps (Satellite Photos)"
will be added to the layer field under the browser field, and the satellite photos will be displayed on themain screen.
4. On the main screen, you can zoom in and out by using the mouse wheel, move by dragging with the left
mouse button, and obtain the coordinates of the mouse position by using the right mouse button.

©️G o o g le Ma p s / Go o g le Ea e rthIn addition, URLs for XYZ tiles are published in various places. Below are URLs for some representative
free XYZ tiles. You can use them according to your purpose.

Goog le Map s
Credits: © Googl eRoad Map

http://mt1.google.com/vt/lyrs=m&x={x}&y={y}&z={z}&s=Ga

Satellite imagery

http://mt1.google.com/vt/lyrs=s&x={x}&y={y}&z={z}&s=Ga

Hybrid satellite imagery

http://mt1.google.com/vt/lyrs=y&x={x}&y={y}&z={z}&s=Ga

Geospatial Information Authority of Japan（Tile List：https ://maps .gs i.go .jp/d e ve lopment/ichiran.h tml ）Credits：© 国土地理院

Standard Map

https://cyberjapandata.gsi.go.jp/xyz/std/{z}/{x}/{y}.png

Latest photos

https://cyberjapandata.gsi.go.jp/xyz/gmld_glcnmo2/{z}/{x}/{y}.png

Color-coded elevation map https://cyberjapandata.gsi.go.jp/xyz/relief/{z}/{x}/{y}.png
Land Cover：GLCNMO

https://cyberjapandata.gsi.go.jp/xyz/gmld_glcnmo2/{z}/{x}/{y}.png

Vegetation: Tree cover rate https://cyberjapandata.gsi.go.jp/xyz/gmld_ptc2/{z}/{x}/{y}.png

Open Street Map （Tile List：https://wiki.openstreetmap.org/wiki/Tiles）
Credits：© OpenStreetMap contributors

Standard
Black & White

http://tile.openstreetmap.org/{z}/{x}/{y}.png
http://tiles.wmflabs.org/bw-mapnik/{z}/{x}/{y}.png

You can also use your own photos or images for the texture layer instead of using the XYZ tiles data. If you
have a GeoTiff format image with pre-embedded geographic information, just drag and drop the GeoTiff
into the layer column on the left side of QGIS to register it. On the other hand, if you use normal jpg or gif
files that do not contain geographic information, you will need to align the photos or images. For instructions
on how to do this, try searching for "QGIS photo alignment" or similar.

5-2. Creating an elevation layer
5-2-1. Prepareing elevation data
To create a terrain for arcAstroVR, you need to prepare theoriginal elevation data.
Elevation data comes in a variety of formats, but this plugin uses animage format called GeoTiff (with the extension .tiff or .tif), which represents
elevation as shades of grey and contains geographic information.

You can register a GeoTiff file in QGIS by dragging and dropping
it into the layer column on the left side of the window.
GeoTiff format elevation data is available for free or for a fee invarious places, and you can also create it from your own survey data.
Here are some free sites that provide it.

©J AX A A W3 D3 0

GeoTiff image example

Japan Aerospace Exploration Agency (JAXA)：ALOS World 3D - 30m (AW3D30)
https://www.eorc.jaxa.jp/ALOS/jp/dataset/aw3d30/aw3d30_j.htm
The Japan Aerospace Exploration Agency (JAXA) is providing global
digital elevation data with a resolution equivalent to 30 meters, taken fromdata acquired by the Advanced Land Observing Satellite (ALOS), free ofcharge (registration required).
1. After registering as a user on the user registration page (https://www.eorc.jaxa.jp/ALOS/aw3d30/registration_j.htm）, a password
will be sent to you by email.

2. Once you have obtained the password, go to the download page （https://www.eorc.jaxa.jp/ALOS/en/aw3d30/data/index.htm）and click on
the area on the map you want to download. If this is your first time, you will
be asked to enter your ID and password here.

AW3D30 のダウンロードページ

3. You cannot download the entire Earth at once, so you need to click on the area and zoom in until it issmall enough to download. Once you zoom in until the "Download" button is visible, press "Download"
to download.

4. A zip file (e.g. N033E130.zip) with the latitude and longitude of the selected area in the file name will be

downloaded. When you unzip the zip file, you will find a file called ALPSMLC30_(latitude andlongitude)_DSM.tif inside. This file is the 30m resolution elevation data GeoTiff used to create theterrain.

Ministry of Economy, Trade and Industry/National Aeronautics and Space
Administration (NASA): ASTER Global 3D Topographic Data
https://gdemdl.aster.jspacesystems.or.jp

Like ALOS World 3D - 30m (AW3D30), this is a freely
available digital elevation data of the entire Earth with aresolution equivalent to 30m. Similarly, you can select an areaon the map and download the GeoTiff.

Geospatial Information Authority of Japan: Basic Map Information Digital Elevation Model DEM5A
https://fgd.gsi.go.jp/download/menu.php
The Geospatial Information Authority of Japan provides free access (registration required) to 5m resolution
elevation data covering all of Japan, mainly based on aerial survey data.
1. When you register as a user on the new registration page（https://ssosv.gsi.go.jp/piss/
Attention.aspx）, a password will be sent to you by email (you will need to complete temporary
registration and full registration).
2. On the download page （https://fgd.gsi.go.jp/download/mapGis.php?tab=dem）, use the "+,-"
buttons in the upper right or rotate the mouse wheel to zoom in and out of the map to an appropriate size,
then click on the area you want to download.
3. The area you clicked will be added to the selection list on the left. Once all the required areas are registeredin the selection list, click the "Confirm download" button below the selection list.
4. Click the "Download this page all at once" button to download. (At this point, you will be asked to log in,
so enter your ID and password. You will also be asked to fill out a simple survey about the purpose of use.)

5. A file called PackDLMap.zip will be downloaded. When you unzip it, you will see that it contains zip filesof further subdivided areas. Even if you unzip this zip of subdivided areas, it will only contain .xml files
and no GeoTiff files. Therefore, you will need to convert it to GeoTiff or use a plugin to load it directly
into QGIS. The following software can convert Geospatial Information Authority of Japanbasic map information to GeoTiff.PackDLMap.zip.
・For Windows: Basic Map Information Elevation DEM Conversion Tool
https://www.ecoris.co.jp/contents/demtool.html
・For Mac: Basic Map Information Conversion (DemConv)
http://www.jizoh.jp/pages/download.html#DemConv

6. If you do not want to create GeoTiff files using
software, you can also use the QGIS plugin"QuickDEM4JP" to import Geospatial Information
Authority of Japan data directly into QGIS.
i. From the QGIS menu, select “Plugins > Manage andInstall Plugins”.
ii. Select "All" from the displayed plugin dialog.表示
iii. Select "QuickDEM4JP" and press the "Install" button.
iv. Click the "QuickDEM4JP" icon button on the second
icon bar to launch the plugin.
v. Select "'xml' or 'zip' containing 'xml'" in Input Settings >Format, and set the area's zip file (FG-GML-4930-72-DEM5A.zip)
etc. in Input Settings > DEM.
（When selecting a file using the "..." button to the right of the
input field, change the drop-down menu at the bottom to "*.zip".）
vi. In Output Settings > Format, check "GeoTiff", and in Output
Settings > Output Destination, specify where to save the created GeoTiff. "CRS" and "Open output file in
QGIS after algorithm is completed" can be left at the default settings.
vii. Press the "OK" button and the GeoTiff will be created and loaded into QGIS.

©Go o g le Ma p s / Go o g le Ea e rth, © 国土地理院 DEM5 A

5-2-2. Registering and merging GeoTiff files
arcAstroVR handles two types of terrain data depending on the scale.
・Wide area terrain: 24.4m mesh resolution, 300km square area.
・Narrow area terrain: 0.1m to 10m resolution, 409.6m to 40960m (resolution x 4096m) square area広
Note that while wide-area topography data is essential, narrow-area topography data is not necessarily required. In
this example, we will create the topography of the Yoshinogari ruins (latitude: 33.326902, longitude: 130.386323),
and for the wide-area topography we downloaded the following data from Jaxa's ALOS World 3D - 30m (AW3D30),
which includes a 150km radius of the Yoshinogari ruins.
・N031E128, N031E129, N031E130, N031E131, N032E128, N032E129, N032E130, N032E131, N032E132,
N033E128, N033E129, N033E130, N033E131, N033E132, N034E128, N034E129, N034E130, N034E131,
N034E132（19 files）

These multiple GeoTiffs are then registered in QGIS and merged into a single layer.

©️G o o g le Ma p s / Go o g le Ea e rth, ©J AX A A W3 D3 0

1. Drag and drop all the downloaded files

named ALPSMLC30_(latitude andlongitude) _DSM.tif into the layer field on
the left side of QGIS. (One file will be
registered as one layer.)

2. Select "QGIS Menu > Raster > Other >Combine (gdal_merge)", and press the "..."
button in the input layer field of the"Combine (gdal_merge)" dialog thatappears.

3. Check the registered GeoTiff layer and clickthe "◀" button in the upper left to return tothe parameter screen.

©️G o o g le Ma p s / Go o g le Ea e rth, ©J AX A A W3 D3 0

4. Press the "..." button in the output layer fieldand set the output destination and output filename (in this case, "User/Iwashiro/
Desktop/30mDEM.tiff").

5. Press the "Execute" button, and when thecalculation is complete, press the "Close"
button to close the "Merge (gdal_merge)"
dialog.

6. A merged layer called "30mDEM" has beencreated in the layers column, so select theindividual layers before the merge and deletethem by right-clicking and selecting "Delete
Layer."

7. Now, multiple GeoTiffs have been registeredin QGIS and integrated into a layer called“30mDEM”.

Similarly, we will create a narrow-area
topography layer from the Geospatial
Information Authority of Japan's "Basic Map
Information Digital Elevation Model DEM5A."
The image used for the narrow area terrain
is fixed at 4096px wide and 4096px high.
Therefore, when using elevation data with a
5m mesh resolution, an area of
4096px*5m=20,480m square is created as thenarrow area terrain. This time, we
downloaded the following data including aradius of 10.24km centered on the Yoshinogari
ruins.

©️G o o g le Ma p s / Go o g le Ea e rth, ©J AX A A W3 D3 0・FG-GML-4930-62-DEM5A, FG-GML-4930-63-DEM5A,FG-GML-4930-72-DEM5A, FG-GML-4930-73DEM5A, FG-GML-5030-02-DEM5A, FG-GML-5030-03-DEM5A, FG-GML-5030-12-DEM5A, FG-GML5030-13-DEM5A

These data are converted to GeoTiff format using the Basic Map Information Conversion Tool, thenregistered in QGIS using the same procedure as above, and integrated into a single layer called "5mDEM."

Map integration©J AX A A W3 D3 0 , © 国土地理院 DEM5 A©J AX A A W3 D3 0 , © 国土地理院 DEM5 A

5-3. Creating a Geoid layer

To know the exact topography in three-dimensional space, geoid data is required inaddition to elevation data. The geoid represents the mean sea level fluctuation from the Earth's
ellipsoid due to local gravity, and has a variation of approximately -67m to +79m. However, thegeoid does not show significant height changes over an area of a few kilometers. Therefore, even
if geoid data is not available, there will be no large difference in relative elevation within the actual
range of use, but if a more precise representation of the terrain is required, geoid data will need tobe taken into consideration. (See 3-2. Ellipsoid Height, Geoid, Elevation)
Geoids are also freely available in various places. The Geospatial Information Authority of Japan
publishes a precise geoid for Japan in xml format, but the GeoTiff data published by AgiSoft is easier to use as
it covers the entire Earth from the start.

AgiSoft（https://www.agisoft.com/
downloads/geoids/）
The geoid data is divided into several files according
to the observation period and measurement accuracy. In
areas where there is little gravity fluctuation, the EGM84
30' geoid model (EPSG::5203) with a resolution of 30'
units is considered sufficient. On the other hand, inareas with complex mountain ranges, the EGM2008 1'
geoid model (EPSG::1027) with a resolution of 1' may be
preferable.
Once you have downloaded the GeoTiff with thedesired resolution, drag and drop the file into the layer
column on the left side of QGIS to register it.

©️Ag iS o ft E GM2 0 0 8 1 ' g e o id m o d e l, ©J AX A A W3 D3 0 , © 国土地理院 DEM5 A

5-4. Creating a Mask Layer
In the arcAstroVR space, when wide-area terrain, narrow-area terrain, and 3D models are set attheir original altitude, the wide-area terrain may protrude above the narrow-area terrain or 3D model, or
the narrow-area terrain may protrude above the 3D model.
The wide-area terrain of a 30m mesh often contains a height error of about 1m, so it is often higher
than the narrow-area terrain that contains a height error of about 10cm.
However, the original purpose is to display the narrow-area terrain over the wide-area terrain, andthe 3D model over the narrow-area terrain, with priority, so that no penetration occurs. Currently,
controlling the display of penetration in the VR space is very burdensome and slows down the operation, so
when creating the terrain in the first place, an automatic process is performed to lower the wide-area terrain
where there is a narrow-area terrain.
Similarly, you can specify terrain descent using a mask layer when you want to suppress the heightof areas with 3D models in narrow-area terrains.

1. In the Layers section, turn off all layers otherthan satellite images so that you can create amask based on the satellite images.
2. Select "QGIS Menu > Layer > Create Layer >New Shapefile Layer". (You can also select"New Primary Scratch Layer" if you don't needto save the mask file.)
3. Click the "..." button next to the file name to
specify the save location and file name. Here, I
chose "/Users/iwashiro/Desktop/mask.shp".
©️G o o g le Ma p s / Go o g le Ea e rth©️G o o g le Ma p s / Go o g le Ea e rth

4. Change the geometry type to "Polygon".
5. Press the "OK" button to close the dialog and "mask" will be added to the layer column on the left in
QGIS.

6. Click the vector layer’s “Edit mode” button (pencil icon),then click the “Add polygon feature” button two buttons to
the right.
7. In the main window, left-click the edges you want to mask to create polygons.
8. Right-click to finish creating the polygon. At this time, you will be asked to enter an ID number, but
you can leave it as "NULL" and click the "OK" button. If necessary, you can continue creating
polygons in other places.
9. Once you have finished creating the mask, press the “Save Layer
Edits” button next to the “Edit Mode” button (pencil icon).
10. This time, I plan to place the 3D polygonized northern inner
bailey of Yoshinogari Ruins on top of the terrain data, so I
specified a mask for the northern inner bailey area.

©️G o o g le Ma p s / Go o g le Ea e rth

5-5. Output of terrain data for arcAstroVR using Plugin
Please confirm that the following layers have been created and registered by completing steps 5-1 to 5-3.
- Wide-area DEM layer (Required: 5-2. Create an elevation layer)- Narrow-area DEM layer (5-2. Create an elevation layer)- Geoid layer (5-3. Create a geoid layer)- Texture layer (5-1. Create a texture layer)- Mask layer (5-4. Create a mask layer)
Next, launch the arcAstroVR plugin from the second row of the QGIS icon bar and configure it asfollows based on the example layers we have created so far.

1. Enter the latitude and longitude of the observation
point in the latitude and longitude fields.
This time, we entered the center location of thenorthern inner bailey of Yoshinogari ruins(latitude 33.326944°, longitude 130.386319°).
2. A red "X" will be displayed at the latitude and longitude you entered, and the area of

the wide-area
terrain will be displayed in red. Check that the DEM file you prepared covers the area of the widearea terrain, and add any that are missing.

3. For the layer settings for wide-area terrain, select
DEM layer: "30mDEM"
Geoid layer: "egm2008-1"
Texture layer: "GoogleMaps (satellite photo)".
Note: If the narrow terrain in the next item is set,
the shape of the wide-area terrain will be corrected
so that it does not cut through the shape of thenarrow-area terrain.
4. In the layer settings for narrow-area terrain, select"5mDEM" for the DEM layer,"egm2008-1" for the Geoid layer,"GoogleMaps (satellite photo)"
for the Texture layer, and set "5.0" for the Mesh (m).
When you enter settings for narrow-area terrain,
the range of the narrow-area terrain is displayedwith a green line. Check that the DEM file you
have prepared covers the range of the narrow-area
terrain, and add any that are missing.
5. For the mask layer, select "mask".
6. I specified "/Users/iwashiro/Desktop/terrain" as the destination folder.
7. Pressing the "OK" button will start creating terrain data for arcAstroVR.
Note: Creating a terrain can take a very long time - a small terrain takes about 10 minutes, a large
terrain takes about an hour.

8. When the creation of the terrain is finished,
the main screen of QGIS will switch to an
orthographic projection, and the layers
wideTerrain_DTM, narrowTerrain_DTM,
wideTerrain_TEX andnarrowTerrain_TEX will be created. Thisis the image data that has been corrected
and processed in various ways forarcAstroVR, and the files (terrain00.raw toterrain33.raw, terrain00.jpg toterrain33.jpg) that have been converted toa format that can be read by arcAstroVR
will be saved in the specified destination
folder.

©️G o o g le Ma p s / Go o g le Ea e rth, ©J AX A A W3 D3 0 , © 国土地理院 DEM5 A

You can see that the created baseTerrain_DTM has beencorrected for terrain irregularities to accommodate thecurvature of the Earth.

5-6. Creating a dataset for arcAstroVR
Copy the dataset folder (data_template) that comes with arcAstroVR and rename it to yourown name. In this example, we renamed it to “data_yoshinogari”.
The dataset folder has the following structure:dataset folder├ dataset.txt ：specification setting file
：Storage for 3D models, avatars, etc.D├ object：Storage location of terrain data
└ terrain

Place all of the files output to the destination folder in step 5-5 into the terrain folder in the dataset folder.
Next, open dataset.txt in a text editor and set the following basic information.
(Note: arcAstroVR Ver.0.17 and later versions support this data format.)•location = "title name"in English•

country = "country name"in English•

timezone = HH:MM

Time zone setting (-12:00 to +13:00) If not set, it will be set to +0:00.

•

date = yyyy/mm/dd•

time = HH:MM:SS•

mesh = numerical value•

type = coordinate system symbol (required)Start date: Year/Month/Day. If not set, the current time will be set.
Start time: hours:minutes:seconds. If not set, the current time will be used.
Mesh resolution of narrow area terrain (m). Please input the value set in the terrain4aAVR plugin for QGIS.
For longitude and latitude notation: WGS84
For Japanese Plane Cartesian Coordinate System 19: JP01-19 (two digits are zone numbers)
For UTM coordinate system: UTM01-60 (two digits are zone numbers)•

center = easting, northing, ellipsoid height (required)
Set the coordinates of the geographic center point.
For WGS84, longitude (°), latitude (°), ellipsoid height (m)For JP**, the Y coordinate (m), X coordinate (m), ellipsoid height (m) of the specified zone number**
For UTM**, the E coordinate (m), N coordinate (m), ellipsoid height (m) of the specified zone number**•

copyright ："broad area credit", "narrow area credit"

The credit name used for the terrain data. You can also set only the wide area terrain.

This time, enter the following:location = "Yoshinogari"country = "Japan"
timezone = +09:00
date = 216/12/12
time = 16:00:00
mesh = 5
type = WGS84
center = 130.386306,33.326917,56
copyright = "Jaxa ALOS(30m mesh DTM)/Google Earth(Photo)","GSI(5m mesh DTM)/Google Earth(Photo)"
This completes the setup of dataset.txt.

Launch Stellarium and arcAstroVR, specify dataset.txt and load it, and the terrain you created will be displayed in the VR space.

©️G o o g le Ma p s / Go o g le Ea e rth, ©J AX A A W3 D3 0 , © 国土地理院 DEM5 A

ContactscienceNODE Kuninori Iwashiro
iwashiro@science-node.com