ProtoBlock — Snap-to-Grid Level Blockout for Blender

Primitives, modular kit pieces, CSG booleans, FBX export with collision — the fastest grayboxing pipeline for Blender.

Why ProtoBlock

Level designers waste hours wrestling Blender's modelling tools to do what should be a single keystroke: drop a wall on the grid, snap a stair into place, boolean a doorway, save the result as a reusable kit piece. ProtoBlock collapses all of that into a single sidebar.

Features

• Grid snap with backup/restore of your existing snap settings
• 8 primitives tuned for level design: box, wedge/ramp, cylinder, arch, stairs, floor, wall, pillar
• CSG booleans — Union / Difference / Intersect with auto-apply
• Kit pieces — save / load reusable modular pieces from a dedicated collection
• Auto box-UV for clean tiling textures on grayboxed walls
• FBX export with a bounding-box collider per block, named for the engine you pick: UCX_ prefix for Unreal, _col for Unity, -col for Godot
• Per-object materials — cycling colors does not recolour everything

Compatibility

• Blender: 4.2 LTS and later (tested on 4.2.9 and 5.2.0)
• OS: Windows / macOS / Linux
• Engines: Unity / Unreal / Godot via FBX

What you get

• ProtoBlock add-on (Python only, no DLL)
• README with full quick-start guide
• Free updates for v1.x
• Support through marketplace messaging

Install

Edit → Preferences → Add-ons → arrow button in the top right corner → Install from Disk → pick the add-on zip → enable. The ProtoBlock sidebar tab appears in the 3D Viewport (press N).

License

GPL-3.0. Standard for Blender add-ons. The licence applies to the add-on code only — the levels you build with it are yours to ship in any commercial project.

1.0.1 — Boolean operations work again on Blender 5.x. The add-on asked the Boolean modifier for a solver named FAST, which Blender has since replaced with FLOAT, EXACT and MANIFOLD — the assignment raised, and Quick Union, cut and difference all failed with it. The solver is now picked from what the running Blender actually offers. Verified: two blocks union into one.