How to Average UV Island Scale in Blender

Averaging UV island scale in Blender is an essential process for maintaining uniform texel density across a 3D model. This ensures that textures apply evenly without stretching or varying in resolution across different parts of the mesh. This article provides a quick, step-by-step guide on how to automatically rescale your UV islands relative to one another in Blender's UV Editor using simple menu commands and keyboard shortcuts.

Step-by-Step Guide to Average UV Island Scale

  1. Enter Edit Mode: Select your 3D object in the 3D Viewport and press Tab to enter Edit Mode. Press A to select all faces of the mesh.
  2. Open the UV Editor: Ensure you have a UV Editor window open, or switch to the default UV Editing workspace tab at the top of the screen.
  3. Select All UVs: Move your mouse cursor into the UV Editor area and press A to select every UV island.
  4. Apply Average Island Scale:
    • Menu Method: Click UV in the top header menu of the UV Editor, then select Average Island Scale.
    • Shortcut Method: Press Ctrl + A while hovering your cursor inside the UV Editor window.

Packing Islands After Rescaling

Rescaling UV islands will often cause them to overlap or extend beyond the standard 0 to 1 UV grid space. To organize them properly:

  1. Keep all UV islands selected (A) inside the UV Editor.
  2. Go to UV > Pack Islands in the top menu or press Ctrl + P.
  3. In the lower-left operator panel (Pack Islands), adjust the Margin value to prevent adjacent islands from touching or causing texture bleeding.

Why Texel Density Matters

Averaging the island scale forces every UV island to match the scale of the physical geometry in the 3D Viewport. This guarantees that a 1024x1024 pixel texture displays at the exact same visual quality across all parts of the object, whether the faces are large or small.