problem with ArcGIS compact cache v2 in local SRS

[Mar-ile]

Context

Hey,
I'm trying to create a WMTS with ArcGIS compat cache v2 as source. I have created two caches one in WebMercator (hereafter as cache 2 - World Map) and one in local SRS (hereafter as cache 1 - Poland Map).

So based on the documentation (https://mapproxy.org/docs/1.13.0/) I managed to load cache 2 (in WebMercator).

For cache 2 I created my own GRID based on WebMercator and defined BBOX, BBOX_SRS, ORIGIN (set to UL or NW) and resolution values (generated with mapproxy-util scales --dpi 96 --as-res-config) - loading and displaying went fine.

services:
  demo:
  tms:
    use_grid_names: true
    origin: ul
  kml:
    use_grid_names: true
  wmts:
  wms:
    md:
      title: MapProxy WMS Proxy
      abstract: This is a minimal MapProxy example.

layers:
  - name: worlds
    title: Cached Test Layer World
    sources: [world_cache]

caches:
  world_cache:
    sources: []
    grids: [world_grid]
    format: "image/png"
    cache:
      type: compact
      version: 2
      directory: C:/Users/ilenc/Desktop/World/cache_data/_alllayers/

grids:
  webmercator:
    base: GLOBAL_WEBMERCATOR
  world_grid:
    base: webmercator
    srs: "EPSG:3857"
    bbox:
      [
        -20037507.229594339,
        -20037507.229594339,
        20037507.229594339,
        20037507.229594339,
      ]
    bbox_srs: "EPSG:3857"
    tile_size: [256, 256]
    origin: ul
    res: [
        #  res              level     scale @96.0 DPI
        156542.7208419323, #  0   591657527.59155500
        78271.3604209660, #  1   295828763.79577702
        39135.6802104831, #  2   147914381.89788899
        19567.8401052414, #  3    73957190.94894400
        9783.9200526207, #  4    36978595.47447200
        4891.9600263104, #  5    18489297.73723600
        2445.9800131552, #  6     9244648.86861800
        1222.9900065776, #  7     4622324.43430900
        611.4950032889, #  8     2311162.21715500
        305.7475016443, #  9     1155581.10857700
        152.8737508223, # 10      577790.55428900
        76.4368754110, # 11      288895.27714400
        38.2184377055, # 12      144447.63857200
        19.1092188528, # 13       72223.81928600
        9.5546094264, # 14       36111.90964300
        4.7773047133, # 15       18055.95482200
        2.3886523567, # 16        9027.97741100
        1.1943261782, # 17        4513.98870500
        0.5971630892, # 18        2256.99435300
        0.2985815445, # 19        1128.49717600
      ]

globals:

For cache 1 I followed a similar procedure, with the difference that it was not based on WebMercator but I defined a local SRS and the other things mentioned above - everything went without problems, but nothing is displayed.

services:
  demo:
  tms:
    use_grid_names: true
    origin: ul
  kml:
    use_grid_names: true
  wmts:
  wms:
    srs: ["EPSG:3857", "EPSG:2180"]
    md:
      title: MapProxy WMS Proxy
      abstract: This is a minimal MapProxy example.

layers:
  - name: poland
    title: Cached Test Layer Poland
    sources: [poland_cache]

caches:
  poland_cache:
    sources: []
    grids: [poland_grid]
    format: "image/png"
    cache:
      type: compact
      version: 2
      directory: C:/Users/ilenc/Desktop/Poland/cahce_data/test_poland_3/tile/

grids:
  poland_grid:
    srs: "EPSG:2180"
    bbox:
      [
        -57484.615432610502,
        64610.002854817547,
        1059423.4743773644,
        832654.60719910637,
      ]
    tile_size: [256, 256]
    origin: nw
    res: [
        #  res            level     scale @96.0 DPI
        4233.3333333333, #  0    16000000.00000000
        2116.6666666667, #  1     8000000.00000000
        1058.3333333333, #  2     4000000.00000000
        529.1666666667, #  3     2000000.00000000
        264.5833333333, #  4     1000000.00000000
        132.2916666667, #  5      500000.00000000
        66.1458333333, #  6      250000.00000000
        # 33.0729166667, #  7      125000.00000000
        # 16.5364583333, #  8       62500.00000000
        # 8.2682291667, #  9       31250.00000000
      ]

globals:

the same transparent tile is returned if I use the re-projection from 3857 to 4326 or 2180.

where am I making a mistake, or is it supposed to work that way ?

Your Environment

• Version used: Mapproxy v 2.0.0 and 2.0.1
• Environment name and version (e.g. Python 2.7.5 with mod_wsgi 4.5.9): python 3.9.18
• Server type and version: -
• Operating System and version: Windows 11 Pro version 22H2

[simonseyock]

Thanks for reporting this issue @Mar-ile

In theory I'd say this should work, but sadly do not have a license for ArcGIS and cannot verify it. If you can provide a sensible fix for this issue, we are happy to assist you in creating a PR for this.