How do I make a render of the Nether roof?
I already tried setting the lighting to shadows instead of nethershadows however that only changed the lighting of where the chunks ended.
I found an old configuration page as it used the parameters maximumheight and minimumheight. However it refers to the configuration.txt which isn't used to configure worlds at least anymore as it is from 2011 and inserting it into my world.txt didn't have any effect.

did you find anything to sort this out? thanks

Giving this a try. Looks like currently minimumheight and maximumheight are still supported in the custom-perspectives.txt file:

perspectives:
  - class: org.dynmap.hdmap.IsoHDPerspective
    name: nether_top_map_lowres
    maximumheight: 256
    minimumheight: 129
    inclination: 90
    scale: 4
    azimuth: 180

The config-based map add that the Reddit thread mentions is optional (and may be outdated even), as you can do something like dmap mapset world_nether:nether_roof perspective:nether_top_map_lowres via the CLI after a reload.

And it seems to want to work after initializing a re-render!

One thing I don't like is the lack of mushrooms to give some sense of scale, and I'm not sure if maps still support the background color attribute, or if I drop minimumheight down one, the bedrock will be rendered as a sort of dark gray by default? I will keep messing around with it..

Edit: Setting minimumheight to 128 does capture the roof surface, but the default bedrock texture is ...kinda nasty imo.

Thanks @depwl9992 .
Would you (or anyone else, for that matter) be able to put together a ELI5 set of steps on how to do this? I tried following your instructions as well as the reddit post. I managed to add.. a map, but it has no icon and the map is just black. I'd really appreciate it :)

Would you (or anyone else, for that matter) be able to put together a ELI5 set of steps on how to do this? I tried following your instructions as well as the reddit post. I managed to add.. a map, but it has no icon and the map is just black. I'd really appreciate it :)

As long as the map itself shows the spawn icon, it should be fine, and eventually update with whatever you have up there, provided you run a fullrender or walk a player up there to load the chunks and let dynmap refresh automatically.

But I get you. The black is annoying, and may be caused by minimumheight=129 which I believe is open air and renders as black, blending perfectly with the black obsidian of any portals you might have placed also.

Additionally, yeah, I get why no icon could also be misleading.

So here is a step-by-step guide of what I did to get this working!

Let me know if it helps!