Mob Spawn Indicator

Highlights block surfaces where hostile mobs can spawn using color-coded overlays. Client-side only, requires NeoForge 1.21.1.

Features

• Scans blocks around the player and draws colored overlays on valid spawn floors
• Color-coded by block light level at the spawn position:
  • Red — block light 0 (mobs can spawn at night)
  • Yellow — block light 1 (spawns only if other conditions suppress light)
  • Green — block light 2+ (safe)
• Uses vanilla spawn rules — respects slabs, stairs, glass, leaves, and other non-spawnable blocks
• Configurable render radius and overlay opacity
• Toggle on/off with keybind (default: J)
• Shows danger, warning, and safe zones independently

Usage

Press J (default) to toggle the overlay on/off. All valid spawn floors within range will be highlighted.

Client-side commands:

• /msi on — enable the overlay
• /msi off — disable the overlay
• /msi toggle — toggle the overlay
• /msi reset — reset the overlay to default settings
• /msi settings — open the settings screen

Configuration

Edit config/msi-common.toml or use a mod menu:

• render_rad — scan radius in blocks (default: 16)
• overlay_opacity — overlay transparency (default: 0.5)
• show_danger — show red zones (default: true)
• show_warn — show yellow zones (default: true)
• show_safe — show green zones (default: false)

Build

Requires JDK 21.

./gradlew build
./gradlew runClient