3D globe view

[silvester-pari]

MVP

• Create globe "plugin" that is not bundled with the rest of eox-map
• Decide on usage of openglobus or Cesium
• Support projection "globe" to render 3d globe
• Render eox-maps as tile providers for 3d globe
• Correctly project the map on the globe (including wrapping correctly in the pacific)
• Support zoom, center, zoomExtent eox-map properties for globe
• Support projection switching (e.g. 3857 -> globe -> 3857) while keeping zoom/position/extent
• Support layer change (re-render tiles)

Potential Evolution

• Basic zoom buttons (either aligned with eox-map or taken directly from eox-map)
• Automatic switching map/globe based on zoom level
• Support "base layers" (rendered natively by openglobus) and "data layers" (rendered as canvas tiles)
• Support mouse events (pass through from globe to map)
• Investigate Vector Tile rendering and potnetial workarounds (currently OL only supports vector tiles in the view projection and the globe needs EPSG:4326)
• Support feature selection (highlight -> re-render tiles)
• Terrain/elevation support
• 2.5D support ("3D flat plane")
• ...