UniMat — Blender Addon for Material Unification

UniMat is a Blender addon that combines multiple materials used across different objects into a single unified material with all texture maps baked into one UV set. This is perfect for optimizing game assets or preparing models for export.

Important: UniMat currently works only with Principled BSDF shader materials. Other shader types (Diffuse BSDF, Glass BSDF, etc.) are not supported yet.

What Does UniMat Do?

UniMat takes all the objects in a collection that have different materials and creates one single material that looks the same but uses fewer resources. It does this by "baking" (converting) all the material information into texture images.

Key Benefits:

• Reduces draw calls for better performance in game engines
• Simplifies material management for complex models
• Maintains visual quality while optimizing assets
• Easy switching between original and unified materials

Main Features

Material Baking

Bake multiple material types into texture maps:

• Color
• Metallic
• Roughness
• Normal
• Alpha

UV Mapping Options

Choose how to handle UV coordinates:

• Smart UV Project - Automatically creates optimized UVs
• Unwrap with Existing Seams - Uses seams you've marked in your model
• Use Existing UV Map - Uses a UV map that's already on your objects

💡 Tip: Smart UV Project and Unwrap methods automatically set a minimum island size to prevent tiny UV islands from being skipped during baking, which avoids unwanted artifacts in your textures.

Flexible Naming

Use naming variables to automatically organize your textures:

• $COLL - Collection name
• $FILE - Blend file name
• $MAP - Map type (Color, Normal, etc.)

Example: $COLL_$MAP becomes MyCollection_Color, MyCollection_Normal, etc.

💡 Tip: Map names (Color, Metallic, Roughness, Normal, Alpha) can be customized in the addon preferences. For example, you can change "Color" to "Albedo" if preferred.

Individual Resolution Control

Set different texture sizes for each map type (128px to 4096px) to optimize file size and quality.

How to Use UniMat

Basic Workflow

1. Organize your objects

   • Put all objects you want to combine into a single collection
   • Select that collection in the Outliner

2. Choose your maps

   • In the UniMat panel (View3D > Sidebar > UniMat tab)
   • Open the "Maps to Bake" section
   • Check the boxes for the maps you need (Color, Normal, etc.)

3. Set resolutions

   • Open the "Map Resolution" section
   • Choose the texture size for each map (higher = better quality but larger files)

4. Configure UV mapping

   • Open the "UV Mapping Method" section
   • Choose how to create or use UV coordinates:
     • Smart UV Project (recommended for beginners) - automatic unwrapping
     • Unwrap with Existing Seams - if you've set up seams manually
     • Use existing UV map - if all objects already share the same UV map name

5. Click "Bake UniMat"

   • The addon will create the unified material and bake all selected maps
   • This may take a few moments depending on your settings

6. Switch between materials

   • Use "Switch UniMat" button to toggle between unified and original materials
   • The unified material is ON when the button shows "Switch UniMat : ON"

Extra Tools

UniMat includes additional utilities:

• Auto UV Collection - Quickly create UV maps for all objects in your collection using the selected UV method and name from the panel settings
• Move UV Map to first/last - Change which UV map is active for the selected object (applies only to the currently selected object, not the entire collection)

Cleaning Up

When you're done or want to start over:

• Click "Clean UniMat Setup" to remove all UniMat-generated data
• This restores your objects to their original state (removes unified material, UV maps, and backup data)

Addon Preferences

Access via Edit > Preferences > Add-ons > UniMat:

• Default Map Names - Customize how each map type is named (Color, Metallic, Roughness, Normal, Alpha)
• UV Settings - Control UV generation parameters:
  • Minimum Island Size
  • Smart UV Angle Limit
  • Island Margin (Learn more about edge padding)
• Bake Settings - Control baking quality and padding: number of samples (higher = better but slower) and bake margin (edge padding in pixels, value shown is for 512px maps)

Tips for Beginners

• Start simple: Try with just Color map first to understand the workflow
• Use Smart UV Project: It's the easiest option if you're new to UV mapping
• Choose appropriate resolutions: 1024px or 2048px is usually good for game assets
• Test before finalizing: Use the Switch UniMat button to compare original vs unified materials
• Keep backups: Save your file before baking complex scenes

Requirements

• Blender 4.2.0 or higher