Greyboxer

A first-person spatial blockout tool for rapidly creating 3D level greyboxes, using intuitive FPS-style controls.

Export models to .glb files. Import directly into Godot Engine with collision included. Excellent for rapid prototyping of level geometry.

Note: this is an early-access alpha build. Some features are rough around the edges. Web build is a demo. Windows build is most tested.

Quick Start

1. Run greyboxer.exe (Windows) or greyboxer.x86_64 (Linux)

2. Press H for the full controls overlay

3. Use WASD to move, mouse to look, LMB to place pieces

Features

• First-person building: place, rotate, flip, scale, and recolor pieces from a FPS perspective

• Built-in primitives: floor, wall, platform, column, ramp, doorway, staircase, cube, railing, half floor, sphere, window, shallow stairs (more to come!)

• Grid snapping: surface-aware snap with 4 grid sizes (0.25m, 0.5m, 1m, 2m)

• Multi-selection: Shift+click to add, Ctrl+click to toggle, Shift+hold+look to sweep-select

• Select by color or type: right-click a palette swatch to select all pieces of that color; Shift+click a piece in the asset browser to select all of that type

• Group manipulation: move, rotate, mirror, and delete groups with full undo

• Copy/paste: Ctrl+C/V with multi-ghost preview, Ctrl+D to duplicate

• Collections: save selections as reusable prefabs (Ctrl+Shift+S)

• Asset kit import: load GLTF/GLB models via manifest.json (Ctrl+I)

• Browser panels: visual asset browser (B) and prefab browser (N)

• Lighting presets: Daylight, Overcast, Night, Interior (L key)

• HUD toggle: hide all HUD elements for clean screenshots (backtick key)

• Grid visibility: cycle grid between full lines, floor-only, and hidden ([ key)

• Undo/redo: all operations are undoable (Ctrl+Z/Y)

• Auto-save: every 2 minutes with crash recovery

• Save/load: JSON project files (Ctrl+S/O)

• GLTF export: export scenes as .glb (Ctrl+E)

Controls

| Key | Action |

| --- | ------ |

| WASD | Move |

| Mouse | Look |

| Space | Fly up / Jump |

| F | Toggle fly/walk |

| Tab | Toggle build/select mode |

| LMB | Place piece / Select |

| RMB | Quick delete (build mode) |

| Shift+LMB | Recolor piece (build) / Add to selection (select) / Select all of type (asset browser) |

| Shift+LMB hold | Sweep-recolor while looking (build) / Sweep-add to selection (select) |

| Ctrl+LMB hold | Sweep-toggle selection (direction locked to first piece) |

| Q / E | Previous / Next piece |

| R | Rotate 90 degrees |

| Y | Vertical mirror (flip upside-down) |

| Shift+Y | Horizontal mirror |

| G | Cycle grid size |

| V | Cycle scale (S/M/L) |

| T | Cycle opacity |

| C | Cycle color |

| 1-0 | Direct palette select |

| Shift+C | Color picker |

| Scroll | Adjust Y offset |

| MMB | Reset Y offset |

| Arrows | Move selection (XZ) |

| PgUp/PgDn | Move selection (Y) |

| Del / X | Delete selection |

| Ctrl+C/V/D | Copy / Paste / Duplicate |

| B / N | Asset browser / Prefab browser |

| Ctrl+Shift+S | Save collection |

| Ctrl+I | Import asset kit |

| Ctrl+S / Ctrl+O | Save / Load |

| Ctrl+E | Export GLTF |

| Ctrl+Z / Ctrl+Y | Undo / Redo |

| L | Cycle lighting preset |

| H | Toggle help |

| ` | Hide/show HUD (screenshot mode) |

| [ | Cycle grid (Full / Floor only / Hidden) |

| Esc | Release/capture mouse |

Asset Kit Format (EXPERIMENTAL ADVANCED FEATURE!)

Create a directory with a manifest.json and GLTF/GLB files:

 {    "kit_name": "My Kit",    "assets": [      {        "file": "model.glb",        "name": "Model Name",        "category": "Buildings",        "collision_type": "trimesh"      }    ]  }  

Import with Ctrl+I and select the manifest file.