Shadows appear to not render correctly on higher quality textures. Map renders in very low quality near edges

[Maciej6542]

What i did / Steps to reproduce

For shadows not rendering correctly: zoom the map into a snowy hills biome (happens regardless of biome, but it is most noticable on this biome)

For map being very low quality: zoom the map near its edge.

Expected result

Shadows and map near edges render correctly

Actual result

Both are rendered incorrectly. Incorrect shadows may make map very inaccurate.

Context

BlueMap Version:
paper-5.16-1.21.11

Used OS and browser while getting the screenshots: Firefox on Linux
Server version: Purpur 1.21.11
Terrain generation got altered by a smaller biomes datapack. The only thing it does is make biomes smaller in area, not height.
Terrain has not been pregenerated.
For snowy biome screenshots, chunks there are often rendered by a player.

The terrain is rendered correctly while lower quality textures are used.

[TBlueF]

Hi!

BlueMap's origin and main purpose is it being a 3D map. So it renders the world into 3d-models which then are being displayed in the webbrowser. And that is also what it is optimised for.
Just like in Minecraft itself, BlueMap can't just show the entire world as one huge 3D model all at once. It would be too much for your GPU. So bluemap uses an LOD-system to display further-away map-tiles with less quality than closer map-tiles.

This lower-resolution LOD is what you see spilling over at the map's edges. I am right now working on a web-app rewrite where I will try to optimise this! This edge-spill is already fixed there :)

For the Shadows: this is because of the way ambient-occlusion is calculated for the full resolution 3d-models: Currently the ambient-occlusion on these models is calculated only for vertices at the edges of the full blocks. The issue with the snow is that it is just small snow-sheets. So their top doesn't get a proper ambient-occlusion calculation.
This is kind of a technical limitation right now with the ao-calculation.

I am aware that this looks especially problematic in 2D/flat-view. Maybe this can be improved in the future. But this is not a priority right now.

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I will close this issue here for now since this is currently more a "missing feature" and not really an important "bug".
But I would be happy to discuss and explain this further in our discord!