Using Corner Detection to Select Very Large Areas

What Corner Detection Does

Corner mode lets a structure block find the opposite corner of a region automatically instead of you typing exact coordinates. Vanilla only searches a short distance, which is why big builds often fail to detect. This mod greatly increases that search range — far enough to span large builds — but the wider the search, the more work the game does, so it is not free.

Selecting a Large Region

1. Place a structure block near one corner of the area you want.

2. Switch it to Corner mode. Remember the mod's quirk: if the mode does not take on the first try, change it again.

3. Place a second structure block (or move to the intended opposite corner) so the block has a target to detect.

4. Trigger the corner detection. The block scans outward across the enlarged range to locate the opposite corner.

5. Check the resulting bounding box. If it is short of your build, move the corner marker closer or reposition and detect again.

6. Once the box is correct, switch to Save or Load mode (toggling twice if needed) and proceed.

Keeping It Fast

Because the search range is now large, avoid leaving corner detection running over huge empty distances. Place your corner markers reasonably close to the actual build edges so the scan finishes quickly, and only widen the search when a build genuinely needs it. If detection feels slow, tighten the markers rather than waiting it out.