Placement Painter Pro — Natural Scatter, Mesh Snapping & Level Design Suite

Build entire environments in minutes, not hours. Placement Painter Pro is a professional Unity level-design and environment-building toolkit that turns prefab placement into a fast, intuitive painting workflow. Instead of manually dragging, rotating, aligning, and duplicating hundreds of objects, paint your environment directly in the Scene View. Create forests, roads, villages, dungeons, farms, industrial zones, survival maps, and detailed modular scenes with powerful placement, snapping, scattering, filtering, physics, and optimization tools.

Eight Powerful Placement and Sculpting Modes:
- Scatter: Paint hundreds of objects naturally with controllable density, radius, rotation/scale jitter, and four falloff curves (Gaussian, Linear, SmoothStep, Uniform).
- Single Place: Precision 1-click placement with a real-time 3D ghost hologram preview and vertex/edge/face snapping.
- Line / Path Placement: Turn a mouse drag into a complete infrastructure run (fences, roads, walls, pipes, utility poles, streetlights) with equidistant spacing and automatic tangent curve alignment.
- Grid Pattern: Generate structured layouts instantly (orchards, crop rows, parking spaces, floor tiles, graveyards) with custom X/Z spacing and staggered rows.
- Physics Drop & Settle: Spawn objects elevated above the ground and let Unity PhysX naturally settle them into place using in-editor simulation. Perfect for rock piles, debris, and fallen crates.
- Modify / Sculpt: Brush over existing painted objects to interactively scale, rotate, re-randomize, or reshape your composition like a 3D environment sculpting tool.
- Replace: Brush over existing objects to swap them with another prefab while maintaining exact position, rotation, and hierarchy.
- Filtered Erase: Clean your environment with precision targeting: All Painted Objects, Active Palette Only, or Selected Prefab Only. Includes optional physics fall-off for stacked debris. (Hold Shift for instant erase).

Intelligent Environment Rules and Filtering:
- Terrain Splatmap / Texture Filtering: Uses Unity Terrain alphamap data so grass only spawns on grass textures, rocks on cliff textures, and pebbles on dirt.
- Slope Angle Filtering: Restrict placement between min and max slope angles (e.g. 0-35 for trees, 30-90 for cliff rocks).
- Altitude Filtering: Gate placement to specific world-height elevation bands (e.g. mountain snowcaps or underwater vegetation).
- Collider Clearance: Prevents unwanted intersections with existing buildings, walls, and structures using Physics.OverlapSphere.

Natural Scattering and Biological Clustering:
- Cluster Scattering: Generates natural groups and sub-clusters so vegetation grows in organic clumps rather than synthetic uniform grids.
- Perlin Noise Density Mask: Uses multi-octave 2D Perlin noise to create organic clearings, meadow openings, and gradual biome transitions.

Scene Eyedropper: Pick Anything Instantly. Found an object in your scene you want to paint with? Press P while hovering in the Scene View to sample it directly into your active brush.

Multi-Prefab Palettes and Gallery:
- Drag and drop prefabs or entire asset folders to build biomes instantly.
- Weighted random distribution across multiple prefabs.
- Multi-Select (Ctrl + Click): Scatter specific subsets of prefabs from your palette.
- High-performance virtualized thumbnail grid capable of smoothly browsing 5,000+ prefabs.

Built for Large Scenes and Optimization:
- Spatial Grid Chunking: Automatically organizes painted objects into coordinate chunks (Chunk_0_0, Chunk_50_0) for optimal occlusion culling and scene streaming.
- 1-Click Static Mesh Combiner: Merge static geometry grouped by material to slash draw calls from hundreds to single digits.
- Scene Analytics HUD: Live counters tracking total painted objects, renderers, estimated triangles, vertices, and material batches.

Safe Editing with Full Undo / Redo: Continuous brush drag strokes are grouped into atomic operations; press Ctrl+Z to undo an entire stroke cleanly with zero data loss.

What's Included:
- Full C# source code with Assembly Definitions (Runtime, Editor, Editor.Tests).
- Custom dockable Editor Window + Scene View Floating Overlay Toolbar.
- 1-Click Demo Content Generator (9 modular prefabs, 2 ready-to-use palettes, 1 brush preset, and an interactive showcase scene).
- Comprehensive User Manual and Quick Start Guide.
- Automated NUnit Editor Tests.