Description
So the viewer in STAC Browser is a "hot topic" right now. I have people asking for more than just COG, e.g. geozarr or COPC. The main issue right now is the proliferation of mapping libraries and it would really not be a good idea to ship 2, 3 or 4 different (mapping/vis) libraries with STAC Browser (primarily looking at Leaflet, OL, Cesium and the Vis.gl/Deck.gl family).
Due to the absence of COG support in OL (at the time of starting STAC Browser v3), the STAC PSC invested into stac-layer, which is an extension for Leaflet.
COG support is available in OL now, which is more robust and faster than the Leaflet implementation, but isn't as good at automatically visualizing "random" COGs and reprojection support is also not as fleshed out (afaik). So for now it's still a bit better to use Leaflet, I'd say.
On the other hand, for (geo)zarr support there's nothing available for Leaflet (I think), but some (proprietary) code for OL.
And lastly, for COPC there's nothing open-source available as far as I know. The COPC viewer (viewer.copc.io) is not open source and it is not planned to make it open source (again: afaik).
So, if you'd need support in STAC Browser for any other format than COG, we'd need an implementation in OL or Leaflet I'd say as otherwise it's a bit out of scope for STAC Browser itself. STAC Browser should really focus on STAC and just re-use what's out there for the file formats, but not invest itself into implementing support for different file formats into mapping libraries. It's just out of scope (and funding).
This also leads to the question which mapping library we want to use long-term.
There's a lot of formats it would be nice to have support for:
- geozarr
- geoparquet
- copc
- COG (which we have support for, but the the implementations in OL/Leaflet have dfferent strengths)
- ...
Ideally these would all be supported by a single mapping library, but that's really just a super-optimistic wish right now. Maybe we can work on this together in the geospatial community. I think it would be super helpful if e.g. OL would support all these formats out of the box. But this will need funding, of course.
PS: I'm just looking at client-side visualization right now as STAC Browser is meant to run without "server-side" component (except for the STAC catalog). Still, some things could also be brought in using server-side components such as TiTiler.