I am able to replicate the issue. The background map layers are provided by the NASA WorldWind service and it appears that the servers are sometimes slow or unresponsive. This data is served by third parties and the Repast team does not have direct control over providing the background map layers. There does appear to be a solution as posted by one of their developers here: https://github.com/NASAWorldWind/WorldWindJava/issues/219 in which they describe how to improve some of the WorldWind network properties to help with the slow servers, and I have tested that this does work.
You will need to copy the below into a file named "worldwind.xml" in your project:
<?xml version="1.0" encoding="UTF-8"?>
<!--
~ Copyright 2006-2009, 2017, 2020 United States Government, as represented by the
~ Administrator of the National Aeronautics and Space Administration.
~ All rights reserved.
~
~ The NASA World Wind Java (WWJ) platform is licensed under the Apache License,
~ Version 2.0 (the "License"); you may not use this file except in compliance
~ with the License. You may obtain a copy of the License at
~ http://www.apache.org/licenses/LICENSE-2.0
~
~ Unless required by applicable law or agreed to in writing, software distributed
~ under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
~ CONDITIONS OF ANY KIND, either express or implied. See the License for the
~ specific language governing permissions and limitations under the License.
~
~ NASA World Wind Java (WWJ) also contains the following 3rd party Open Source
~ software:
~
~ Jackson Parser – Licensed under Apache 2.0
~ GDAL – Licensed under MIT
~ JOGL – Licensed under Berkeley Software Distribution (BSD)
~ Gluegen – Licensed under Berkeley Software Distribution (BSD)
~
~ A complete listing of 3rd Party software notices and licenses included in
~ NASA World Wind Java (WWJ) can be found in the WorldWindJava-v2.2 3rd-party
~ notices and licenses PDF found in code directory.
-->
<!--$Id: worldwind.xml 2348 2014-09-25 23:35:46Z dcollins $-->
<!--Default WorldWind configuration values-->
<!--Any of these can be overridden by specifying an application configuration document-->
<!--An alternate document to this one can also be specified-->
<!--See the javadoc for the Configuration class for details-->
<WorldWindConfiguration version="1">
<!--The initial layer list can be embedded here or linked as below. To change the set of initial layers,-->
<!--modify the file identified by the href or replace the link with your own-->
<LayerList href="config/worldwind.layers.xml"/>
<!--Most configuration information is defined in attribute-value pairs-->
<Property name="gov.nasa.worldwind.avkey.ModelClassName" value="gov.nasa.worldwind.BasicModel"/>
<Property name="gov.nasa.worldwind.avkey.GlobeClassName"
value="gov.nasa.worldwind.globes.Earth"/>
<Property name="gov.nasa.worldwind.avkey.EarthElevationModelConfigFile"
value="config/Earth/EarthElevations2.xml"/>
<Property name="gov.nasa.worldwind.globes.GeographicProjectionClassName"
value="gov.nasa.worldwind.globes.projections.ProjectionEquirectangular"/>
<Property name="gov.nasa.worldwind.avkey.InitialLatitude" value="38"/>
<Property name="gov.nasa.worldwind.avkey.InitialAltitude" value="19.07e6"/>
<Property name="gov.nasa.worldwind.avkey.ViewClassName" value="gov.nasa.worldwind.view.orbit.BasicOrbitView"/>
<Property name="gov.nasa.worldwind.avkey.ViewInputHandlerClassName"
value="gov.nasa.worldwind.view.orbit.OrbitViewInputHandler"/>
<Property name="gov.nasa.worldwind.avkey.InputHandlerClassName" value="gov.nasa.worldwind.awt.AWTInputHandler"/>
<Property name="gov.nasa.worldwind.avkey.LoggerName" value="gov.nasa.worldwind"/>
<Property name="gov.nasa.worldwind.avkey.WorldWindowClassName"
value="gov.nasa.worldwind.WorldWindowGLAutoDrawable"/>
<Property name="gov.nasa.worldwind.avkey.ElevationModelFactory"
value="gov.nasa.worldwind.terrain.BasicElevationModelFactory"/>
<Property name="gov.nasa.worldwind.avkey.LayerFactory" value="gov.nasa.worldwind.layers.BasicLayerFactory"/>
<Property name="gov.nasa.worldwind.avkey.ShapefileLayerFactory"
value="gov.nasa.worldwind.formats.shapefile.ShapefileLayerFactory"/>
<Property name="gov.nasa.worldwind.avkey.WebViewFactory"
value="gov.nasa.worldwind.util.webview.BasicWebViewFactory"/>
<Property name="gov.nasa.worldwind.avkey.TessellatorClassName"
value="gov.nasa.worldwind.terrain.RectangularTessellator"/>
<Property name="gov.nasa.worldwind.avkey.MemoryCacheSetClassName"
value="gov.nasa.worldwind.cache.BasicMemoryCacheSet"/>
<Property name="gov.nasa.worldwind.avkey.SessionCacheClassName" value="gov.nasa.worldwind.cache.BasicSessionCache"/>
<Property name="gov.nasa.worldwind.avkey.RetrievalServiceClassName"
value="gov.nasa.worldwind.retrieve.BasicRetrievalService"/>
<Property name="gov.nasa.worldwind.avkey.SceneControllerClassName"
value="gov.nasa.worldwind.StereoOptionSceneController"/>
<Property name="gov.nasa.worldwind.avkey.NetworkStatusClassName"
value="gov.nasa.worldwind.util.BasicNetworkStatus"/>
<Property name="gov.nasa.worldwind.render.PointPlacemarkAttributes.DefaultImagePath"
value="images/pushpins/plain-yellow.png"/>
<Property name="gov.nasa.worldwind.render.PointPlacemarkAttributes.DefaultLabelFont"
value="Arial-BOLD-14"/>
<!-- The following lists the sites to test for public network access. Specify an empty string, "", for no sites.-->
<!-- Don't specify the property at all to use the default list. -->
<Property name="gov.nasa.worldwind.avkey.NetworkStatusTestSites"
value="www.nasa.gov, worldwind.arc.nasa.gov, google.com, microsoft.com, yahoo.com"/>
<Property name="gov.nasa.worldwind.avkey.TaskServiceClassName" value="gov.nasa.worldwind.util.ThreadedTaskService"/>
<Property name="gov.nasa.worldwind.avkey.DataFileStoreClassName"
value="gov.nasa.worldwind.cache.BasicDataFileStore"/>
<Property name="gov.nasa.worldwind.avkey.DataRasterReaderFactoryClassName"
value="gov.nasa.worldwind.data.BasicDataRasterReaderFactory"/>
<Property name="gov.nasa.worldwind.avkey.DataFileStoreConfigurationFileName" value="config/DataFileStore.xml"/>
<Property name="gov.nasa.worldwind.avkey.WorldMapImagePath" value="images/earth-map-512x256.dds"/>
<Property name="gov.nasa.worldwind.StarsLayer.StarsFileName" value="config/Hipparcos_Stars_Mag6x5044.dat"/>
<!--The following are tuning parameters for various WorldWind internals-->
<Property name="gov.nasa.worldwind.avkey.RetrievalPoolSize" value="32"/>
<Property name="gov.nasa.worldwind.avkey.RetrievalQueueSize" value="400"/>
<Property name="gov.nasa.worldwind.avkey.RetrievalStaleRequestLimit" value="60000"/>
<Property name="gov.nasa.worldwind.avkey.TaskPoolSize" value="32"/>
<Property name="gov.nasa.worldwind.avkey.TaskQueueSize" value="60"/>
<Property name="gov.nasa.worldwind.avkey.ScheduledTaskPoolSize" value="1"/>
<Property name="gov.nasa.worldwind.avkey.VerticalExaggeration" value="1"/>
<Property name="gov.nasa.worldwind.avkey.URLConnectTimeout" value="8000"/>
<Property name="gov.nasa.worldwind.avkey.URLReadTimeout" value="10000"/>
<Property name="gov.nasa.worldwind.avkey.TextureCacheSize" value="500000000"/>
<Property name="gov.nasa.worldwind.avkey.ElevationTileCacheSize" value="20000000"/>
<Property name="gov.nasa.worldwind.avkey.ElevationExtremesLookupCacheSize" value="20000000"/>
<Property name="gov.nasa.worldwind.avkey.SectorGeometryCacheSize" value="10000000"/>
<Property name="gov.nasa.worldwind.avkey.TextureTileCacheSize" value="10000000"/>
<Property name="gov.nasa.worldwind.avkey.PlacenameLayerCacheSize" value="4000000"/>
<Property name="gov.nasa.worldwind.avkey.AirspaceGeometryCacheSize" value="32000000"/>
<Property name="gov.nasa.worldwind.avkey.VBOUsage" value="true"/>
<Property name="gov.nasa.worldwind.avkey.VBOThreshold" value="30"/>
<Property name="gov.nasa.worldwind.avkey.OfflineMode" value="false"/>
<Property name="gov.nasa.worldwind.avkey.RectangularTessellatorMaxLevel" value="30"/>
<Property name="gov.nasa.worldwind.StereoFocusAngle" value="1.6"/>
<Property name="gov.nasa.worldwind.avkey.ForceRedrawOnMousePressed" value="f"/>
<!-- Here's one way to specify proxy settings -->
<!--<Property name="gov.nasa.worldwind.avkey.UrlProxyHost" value="100.215.10.20"/>-->
<!--<Property name="gov.nasa.worldwind.avkey.UrlProxyPort" value="8080"/>-->
<!--<Property name="gov.nasa.worldwind.avkey.UrlProxyType" value="Proxy.Type.Http"/>-->
<!-- Location of icons for MIL-STD-2525C symbol set. This can be a URL to a web server, to a local zip or jar archive.
See https://goworldwind.org/developers-guide/symbology/tactical-symbols/#offline-use for more information on how
to configure a local symbol repository.
Examples: http://myserver.com/milstd2525/ (web server)
jar:file:milstd2525-symbols.zip! (local zip archive) -->
<Property name="gov.nasa.worldwind.avkey.MilStd2525IconRetrieverPath"
value="https://worldwind.arc.nasa.gov/milstd2525c/rev1/"/>
</WorldWindConfiguration>
For testing with the Repast Geography demo, I placed the worldwind.xml file in the geograph.styles folder. And then in the ContextCreator.java add the following:
static
{
System.setProperty("gov.nasa.worldwind.app.config.document",
"geography/styles/worldwind.xml");
}
This will tell WorldWind where to find the modified worldwind.xml file. You will need to repeat this process for any other Repast model that uses the background NASA layers. Apologies for this clunky workaround. We will fix this in the next Repast release so that you don't need to manually perform these changes.
