Some cells refuse to render when heightmap smoothing is used… inventively

[AmarineSilver]

Describe the bug

Some cells refuse to render on the map proper; the invisible cells are always split by continent - they are contiguous with one another and with no unaffected cells, though more than one group of cells may be affected. Reloading the page and reloading the map from a saved file had no effect.

Steps to reproduce

Open a map and navigate to "Tools", selecting "Edit Heightmap". Arrange structures in the template editor to create a map with very, VERY little actual land (perhaps even none at all) that still retains some non-zero amount of variation in height (one or two cells somewhere with a height of 1 or 2 is sufficient). Next, add a "Smooth" function and set the degree to a small decimal quantity (≤ 0.005 is the zone I was in). Scan the resulting map closely; one or more contiguous landforms may have failed to render (discernible by labels, lakes, markers, and/or borders which are apparently in the middle of the ocean).

Expected behavior

Expected behavior was that all regions of the map would be visible on the map.

.map file

Kanaka 2025-12-13-18-37.map copy.zip

Screenshots

System

• Version: 1.108.13
• Browser: Safari
• OS: macOS Sequoia 15.6.1

[Azgaar]

Hello. Yes, in some configuration the island detection algorithm fails. It's a known issue, I don't really know how to fix it properly.