What gets downloaded
MeshBench fetches things it needs and keeps them. The Resources page, under File, is where those live: what is on the disk, how much of it there is, what terms it arrived under, and how to remove it.
It exists because the caches are larger than people expect. Terrain for a country runs to several gigabytes, and until this page there was nothing in the application that would say so.
What is listed#
| fetched | why it is here | |
|---|---|---|
| Terrain tiles | as the map is used | height data under every link budget |
| Map tiles | as the view needs them | the map imagery itself |
| Basemap | as the map is used | the hillshaded ground under the simulation |
| Building footprints | when asked | heights and materials that stand in the way of a signal |
| Nordic SoftDevice | only when asked | nRF52 boards boot MBR, then SoftDevice, then MeshCore |
Firmware is not on this page. It has a page of its own, because a firmware image is a choice about what to run rather than a cost on the disk.
Two kinds of thing#
Most of these fill themselves. Pan the map and terrain arrives; the cache is a consequence of using the application rather than a decision anybody made. Those rows show what they have cost and offer to remove it, and their Fetch button is disabled with the reason given - there is nothing to ask for out of context.
The SoftDevice is the exception, and is fetched only on request. It is somebody else's licensed binary, and the terms should arrive where a person sees them rather than appear on a disk unannounced. The licence is downloaded beside the image and shown on the row.
Terms#
Every row can show what its contents arrived under. Terrain is Copernicus DEM and NASA SRTM; the map imagery and the building footprints derive from OpenStreetMap under the ODbL; the SoftDevice carries Nordic's own agreement.
Attribution is not optional and not only a courtesy: any map published from a MeshBench simulation carries OpenStreetMap's, which is why the application draws each layer's attribution on the map itself.
Removing something#
Remove asks twice, in place. What it deletes is a cache, so nothing is lost that cannot be fetched again - but a terrain cache rebuilt over a metered connection is worth thinking about first, which is why the size is on the row.
Sizes#
A measured size is stated plainly; an estimate carries a ~. Nothing that has not been measured is shown as zero, because a page about disk usage that prints 0 B for a cache it has not looked at is lying about the disk.
From a script#
The control socket carries the same operations, so a fixture-preparation script or a CI runner can warm or clear a cache without the interface:
resource.list what is on the disk
resource.fetch get one, as a job that can be stopped
resource.remove delete one
resource.licence the terms, and resource.licence.hide to put them awayA cache that fills itself refuses resource.fetch and says why, rather than appearing to succeed. See the control socket reference.