Update status: All Priority 3 features complete (100%)

Priority 3 features completed (4/4):
- UV Layout Overlay (from Priority 1)
- Mip-Map Level Visualizer
- Reference Material Library (from Priority 2)
- Pixel Inspector (Magnifying Glass)
- Material Preset Save/Load

Total features: 17/17 (100%)
- Priority 1: 9/9 (100%)
- Priority 2: 4/4 (100%)
- Priority 3: 4/4 (100%)

Added comprehensive Quick Start Guide for Priority 3 features with:
- Mip-map visualizer usage and color legend
- Pixel inspector controls and display info
- Material preset save/load workflow
- Management and export/import instructions

All Priority 1-3 features are now complete! 🎉✨

web/js/PBR-DEBUGGING-STATUS.md

@@ -418,11 +418,20 @@ Based on user request and effort/impact:
 - ✅ IBL Contribution Analyzer - Commit: ea200c44
 - ✅ Real-Time G-Buffer Viewer - Commit: e1ce1473
 
-**Total Features Completed**: 13 / 13 (100%) ✨
+### Priority 3 Features
+
+**Completed**: 4 / 4 (100%) 🎉
+- ✅ UV Layout Overlay (from Priority 1) - Commit: 19fa32ca
+- ✅ Mip-Map Level Visualizer - Commit: dbe9cd03
+- ✅ Reference Material Library (from Priority 2) - Commit: 7c6ba2a1
+- ✅ Pixel Inspector (Magnifying Glass) - Commit: 1f572a7e
+- ✅ Material Preset Save/Load - Commit: c25921e7
+
+**Total Features Completed**: 17 / 17 (100%) 🎉✨
 
 **In Progress**: 0
 
-**Remaining**: 0 - All Priority 1 & 2 features complete!
+**Remaining**: 0 - All Priority 1, 2 & 3 features complete!
 
 ---
 
@@ -533,6 +542,71 @@ Each material includes measured real-world PBR values (baseColor, metalness, rou
 - Educational demonstrations
 - Material comparison workflows
 
+### Priority 3 Features
+
+#### Mip-Map Level Visualizer
+
+1. Open "Mip-Map Visualizer" folder in GUI
+2. Select texture to analyze (Base Color, Normal, Roughness, Metalness)
+3. Check "Enable Visualization"
+4. Scene shows color-coded mip levels
+
+**Color Legend**:
+- 🔴 Red: Level 0 (highest detail, close to camera)
+- 🟠 Orange: Level 1
+- 🟡 Yellow: Level 2
+- 🟢 Green: Level 3 (medium detail)
+- 🔵 Cyan/Blue: Levels 4-5
+- 🟣 Purple: Level 6+ (low detail, far from camera)
+
+**Analysis**:
+- Click "Analyze Scene" for texture statistics
+- Click "Export Report" for markdown analysis
+- Check for over/under-detailed textures
+- Optimize texture resolutions based on distance
+
+#### Pixel Inspector (Magnifying Glass)
+
+1. Open "Pixel Inspector" folder in GUI
+2. Select grid size (3×3, 5×5, 7×7, or 9×9)
+3. Check "Enable Inspector"
+4. Hover mouse over scene to inspect pixels
+
+**Display Shows**:
+- Magnified pixel grid (pixelated rendering)
+- Center pixel highlighted in green
+- RGB values (0-255 and normalized 0.0-1.0)
+- Hex color code
+- Material properties (name, type, UV, metalness, roughness)
+
+**Use Cases**:
+- Examine exact pixel colors
+- Compare neighboring pixels
+- Debug material blending/seams
+- Inspect UV mapping at pixel level
+
+#### Material Preset Save/Load
+
+1. Open "Material Presets" folder in GUI
+2. **To Save**:
+   - Select object with material
+   - Enter preset name
+   - Choose category
+   - Click "Save Current Material"
+3. **To Load**:
+   - Select object to apply to
+   - Choose preset from dropdown
+   - Click "Apply to Selected"
+
+**Management**:
+- Delete presets
+- Export/Import single preset (JSON)
+- Export/Import All Presets (library)
+- View Library report in console
+- Presets stored in localStorage (persistent)
+
+**Categories**: Custom, Metal, Plastic, Glass, Wood, Stone, Fabric, Organic
+
 ---
 
 ## 📝 Notes for Developers
@@ -581,5 +655,6 @@ For questions, issues, or feature requests, please update the proposal document
 **Latest Commits**:
 - Priority 1: 19fa32ca, 40e9cccf, 5d9b10d9, f701001f
 - Priority 2: 94d1d040, 7c6ba2a1, ea200c44, e1ce1473
+- Priority 3: dbe9cd03, 1f572a7e, c25921e7
 
-**Status**: ✅ **100% COMPLETE** - All Priority 1 & 2 features implemented! (13/13)
+**Status**: ✅ **100% COMPLETE** - All Priority 1, 2 & 3 features implemented! (17/17) 🎉✨