3D Model Optimizer — Blender Add-on

A Blender add-on that optimizes 3D models — in particular those generated by AI tools — for web, game-engine, and real-time use. Fixes geometry issues, reduces polygon count, cleans up textures, and exports to GLB, FBX, or OBJ.

Note: The add-on was previously called AI 3D Model Optimizer. The "AI" prefix was dropped to avoid the implication that AI is used to perform the optimizations — the optimizations themselves are standard geometry and texture processing steps.

Upgrading from a previous version? Because the add-on ID changed, Blender treats this as a new extension and cannot migrate your saved preset. After installing, configure your preferred settings and click Save as Default to create a new default preset.

Features

• Fix Geometry — Merge close vertices, recalculate normals, fix non-manifold geometry
• Merge Materials — Merge materials with identical shader setups to reduce draw calls
• Join Meshes — Join mesh objects sharing materials (by material or all into one)
• Remove Interior — Remove hidden interior geometry (Loose Parts or Ray Cast method)
• Remove Small Pieces — Delete disconnected mesh islands below a face count or size threshold
• Symmetry Mirror (Experimental) — Detect near-symmetric meshes and apply mirror optimization
• Decimate — Reduce polygon count using collapse decimation with configurable ratio, optional multi-pass refinement, UV-seam protection, and a planar pre-pass that merges flat regions before collapse
• Bake Normal Map — Bake high-poly surface detail into a normal map before decimating (requires Cycles)
• Clean Duplicate Images — Pixel-content-based deduplication (safe for multi-import sessions)
• Clean Unused Data — Remove orphaned materials, textures, and meshes
• Resize Textures — Downsize or resize all textures to a maximum resolution
• Export to GLB / FBX / OBJ — Pick the format from a single dropdown. GLB has Draco mesh compression and configurable image format (WebP/JPEG/PNG); FBX has axis presets for Unreal Engine and Unity; OBJ writes a companion .mtl for materials
• LOD Generation — Export multiple LOD levels as separate files in the chosen format, with configurable ratios
• Mesh Analysis — Analyze mesh problems and get optimization recommendations for decimate ratio and merge distance
• Full Pipeline — Run all enabled steps in one click with toggleable stages
• Pipeline Progress — Live progress panel showing per-step status, sub-step progress, timing, and overall completion
• Pipeline Summary — Results panel shows total face reduction, export file size, and elapsed time at a glance
• Cancellable Pipeline — Cancel mid-pipeline with ESC or a Cancel button; all changes are automatically undone
• Presets — Save, load, and reset default settings across sessions
• Verbose Logging (opt-in) — Detailed per-step diagnostics (settings consumed, checkpoints, elapsed time) with an Open Debug Log button to write the buffered log to a file and open it in your OS text editor

Requirements

• Blender 4.2 or newer
• Optional: 3D Print Toolbox

Installation

1. Download blender_model_optimizer-X.Y.Z.zip from the latest release
2. Drag-and-drop the .zip into Blender, or go to Edit → Preferences → Add-ons → Install from Disk and select the file
3. Enable the add-on by checking the box next to "3D Model Optimizer"

Usage

1. Open the sidebar in the 3D Viewport by pressing N
2. Click the 3D Optimizer tab
3. (Optional) Click Run Analysis to inspect mesh problems and get recommended settings
4. Adjust settings in the sub-panels (Clean & Prepare Geometry, Remove Interior, Remove Small Pieces, Symmetry Mirror, Decimate, Textures, Export)
5. Click Run Full Pipeline to run all enabled steps, or use individual step buttons
6. While the pipeline runs, a Pipeline Progress panel shows each step's status and timing
7. After completion, a summary box shows total face reduction and export file size
8. Press ESC or click Cancel Pipeline to abort — all changes will be rolled back

Settings

Geometry

Setting	Default	Description
Merge Distance	0.1 mm	Threshold for merging close vertices
Recalculate Normals	On	Fix flipped normals
Manifold Fix	Fill Holes	Off / Fill Holes (n-gon hole filling, safe on thin shells) / 3D Print Toolbox (aggressive cleanup for watertight solids, requires the plugin — destroys thin-shell meshes)
Merge Materials	On	Merge materials with identical shader setups
Material Tolerance	1%	Color/value tolerance when comparing material properties
Join Meshes	On	Join mesh objects that share materials
Join Mode	By Material	Group by shared material, or join all into one mesh

Remove Interior

Setting	Default	Description
Method	Ray Cast	Loose Parts (fast, disconnected geometry) or Ray Cast (slower, catches interior faces in connected meshes)

Remove Small Pieces

Setting	Default	Description
Min Faces	50	Delete loose parts with fewer than this many faces
Min Size	1.0 cm	Delete loose parts smaller than this cube edge length

Mesh Analysis

Setting	Default	Description
Target	Web	Target platform preset: Mobile (~5K faces), Web (~25K), Desktop (~75K), or Custom
Target Faces	25,000	Custom target face count (when Target = Custom)

Symmetry Mirror (Experimental)

Setting	Default	Description
Axis	X	Axis to test symmetry along
Threshold	1.0 mm	Max distance between a vertex and its mirror to count as matched
Min Score	0.85	Minimum fraction of vertices that must have a mirror match

Decimate

Setting	Default	Description
Decimate Ratio	0.1	Keep ~10% of the original face count
Passes	1	Split COLLAPSE into N passes targeting the same final ratio. Higher values preserve silhouette and texture detail at aggressive ratios
Protect UV Seams	On	Bias COLLAPSE ~5× against collapsing vertices near UV island boundaries. Prevents texture smearing on fragmented-UV meshes
Planar Pre-Pass	On	Before COLLAPSE, merge near-coplanar faces into n-gons (UV-island-preserving). Frees COLLAPSE's budget for curved geometry
Planar Angle	5°	Max angle between adjacent faces for the planar pre-pass to merge them. 10–15° reduces more faces but may flatten subtle curvature
Bake Normal Map	On	Bake high-poly detail into a normal map before decimating
Normal Map Size	1024 px	Resolution of the baked normal map
Auto Cage Distance	On	Set bake ray distance to 1% of the mesh bounding-box diagonal (scale-independent)
Cage Extrusion	10 mm	Manual bake ray distance (used when Auto Cage Distance is off)

Textures

Setting	Default	Description
Max Texture Size	1024 px	Maximum texture dimension in pixels
Resize Mode	Downsize Only	Only shrink oversized textures, or resize all to exactly max size

Export

Setting	Default	Description
Format	GLB	Output format: GLB (web/real-time, default), FBX (game engines), or OBJ (DCC interchange). Filename auto-swaps its extension when the format changes
Output Folder	~/Downloads	Output folder
Filename	optimized_model.glb	Output filename (extension follows the Format choice)
Selected Only	On	Export only selected objects
GLB-only
Draco Compression	On	Enable Draco mesh compression (recommended for web)
Draco Level	6	Compression level (0-10, higher = smaller file)
Position Bits	14	Draco position quantization bits (lower = smaller, less precision)
Normal Bits	10	Draco normal quantization bits
UV Bits	12	Draco UV quantization bits
Image Format	WebP	Texture format in exported GLB (WebP / JPEG / PNG)
Image Quality	85	JPEG/WebP quality (1-100)
FBX-only
Axis Preset	Unreal Engine	Pre-configured axis and scale settings for the target engine: Unreal Engine (1 unit = 1 cm), Unity (1 unit = 1 m), or Blender Default
Embed Textures	On	Pack textures into the .fbx so the file is portable; off references them externally
Smoothing	Face	Smoothing groups written to the FBX (Off / Face / Edge)
OBJ-only
Export Materials	On	Write a companion .mtl file referencing the materials
Forward Axis	-Z	Forward axis written to the OBJ
Up Axis	Y	Up axis written to the OBJ
LOD
LOD Generation	Off	Generate multiple LOD levels as separate files in the chosen format
LOD Levels	3	Number of LOD levels (including full-detail LOD0)
LOD Suffix Pattern	_LOD{n}	Filename suffix pattern ({n} = LOD level number)
LOD Ratios	1.0, 0.5, 0.25	Comma-separated decimate ratios per LOD level

License

This project is licensed under the MIT License.