Hopper Lock Visualizer

Built an item sorter and something isn’t working? One of your hoppers is probably receiving an unintended redstone signal. This client-side mod wraps every locked hopper near you in a bright red outline, so you can spot the culprit at a glance.

What “Locked” Means

A hopper has two states controlled by the enabled block property:

Enabled (default): pulls items in from above, pushes items out the spout. Normal behavior.
Disabled (locked): frozen. Completely stops item transfer. Triggered by any redstone signal reaching the hopper — a torch, a pressure plate, a comparator, a stray wire from a neighboring circuit…

When a big contraption stops working, 9 times out of 10 the cause is a hopper accidentally receiving a redstone signal from something nearby. This mod makes that invisible problem visible.

Features

One-key toggle — default H (rebindable in Options > Controls)
32-block radius scan around the player, refreshed twice per second
Smart culling — distance + cone-based visibility check, so only hoppers in view get drawn
Red wireframe rendering using Minecraft 1.21.11’s new Gizmo API
Client-only — works on any server, no server-side install needed
Zero configuration — install and press H

Usage

Install this mod and Fabric API
Drop both into your .minecraft/mods/ folder
Launch Minecraft, join any world or server
Press H → nearby locked hoppers get wrapped in a red outline
Press H again to disable

Compatibility

Untested

Quilt: Not tested, but should work since Quilt supports Fabric mods
Forge/NeoForge: Not supported

Performance

The scan runs 2× per second, not every frame. Each scan reads block states only (no block entities, no inventories), so even in large bases with hundreds of hoppers the overhead is negligible. The render pass culls with distance + cone checks before calling Minecraft’s Gizmo API — no manual matrix math, no state leaks

Hopper Lock Visualizer

截图

介绍