A grid-based level designer that lives inside the Unity editor. Build levels by clicking-and-dragging prefab brushes onto a snap-to-grid surface, then export the result as a portable JSON layout your runtime can consume.

Highlights

• Prefab brushes — assign any prefab as a brush, pick from a palette, paint
• Multi-layer support — floor, walls, props, lighting on independent grids
• Undo / redo — fully integrated with Unity’s undo stack
• Export — JSON, prefab, or both
• Symmetry tools — mirror, rotate, randomize-within-set

API

using StudioTools.GridDesigner;

// Programmatic placement
GridDesigner.Active.Paint(new Vector2Int(3, 5), brushId: "wall_corner");
GridDesigner.Active.Export(path: "Assets/Levels/level_01.json");

Built originally for our internal level prototyping; battle-tested on three shipped projects. Source is included — fork freely.