Nexo Mod 0.4.0-alpha

Bedrock hole finder

Finds gaps sealed inside the world's bedrock boundary layers — the Overworld floor, the Nether floor, and the Nether roof — in the chunks you have loaded, and outlines them through the terrain. No world seed needed, so it finds openings other players broke as well as ones generation left.

• Connectivity, not columns. It flood-fills through anything that isn't bedrock (deepslate, dirt, netherrack, lava, air) inside the layer and keeps only regions that close off within the size range you set. Testing each column instead can't tell a real gap from the four-deep dents generation leaves — that reported a "hole" about twenty times per chunk.
• Two size sliders set the smallest and largest pocket that counts, which is how you tune out the single walled-in blocks generation is full of.
• One merged shape per hole, not a box per block: interior walls are dropped, only edges where the surface turns are drawn, and the whole thing cycles the hue.
• Announced once, ever — per world and dimension, recorded in config/nexomod-bedrock-holes.json, so rejoining doesn't re-announce old finds. Chat, toast, and chime toggle independently.
• Streaming-safe. Coordinates in notifications can be turned off, and are withheld automatically while Position Obscuring is hiding your F3 coordinates.
• Vanilla's in-wall screen overlay is suppressed while the finder is on, so the outlines stay visible while you're inside the layer.

Configure it under Nexo Settings → Bedrock Holes; the toggle can also be bound to a key in Controls.

Requires Minecraft 26.1.2, Fabric Loader 0.19.3+, Java 25+, Fabric API.