How to Display UV Distortion Overlays in Blender

Displaying UV distortion overlays in Blender is an essential step for 3D artists to identify stretching or compression in texture maps. By enabling the stretching overlay in the UV Editor, Blender visually highlights distorted mesh faces using a color-coded heat map. This guide explains how to enable the UV distortion overlay, interpret the color feedback, and fix stretching issues directly in your workflow.

Enabling the UV Distortion Overlay

To view distortion on your UV map, you must turn on the stretch overlay within the UV Editor window:

  1. Select your 3D object in the Viewport and press Tab to enter Edit Mode.
  2. Select the geometry you want to view by pressing A to select all faces.
  3. Switch to the UV Editing workspace, or open a UV Editor window.
  4. In the top-right corner of the UV Editor, click the Display Overlays icon (represented by two overlapping circles).
  5. Check the box labeled Display Stretch.

Once enabled, your UV islands will change color based on the amount of distortion present on the mesh.

Choosing Distortion Types: Angle vs. Area

Blender offers two modes to measure UV stretching. You can toggle between them in the Display Stretch dropdown menu:

  • Angle: Displays distortion based on vertex angles. This mode shows where faces are visually twisted or skewed out of shape.
  • Area: Displays distortion based on face surface area. This mode shows where UV faces are larger or smaller than their corresponding 3D mesh counterparts.

Understanding the Distortion Heat Map Colors

Blender uses a standardized color gradient to represent distortion levels:

  • Dark Blue: No distortion. The UV layout perfectly matches the 3D geometry's proportions.
  • Cyan and Green: Low to moderate distortion. This is often acceptable depending on the detail level of the texture.
  • Yellow and Red: High distortion. Red areas indicate extreme stretching or compression, which will cause textures to appear blurry, pulled, or squashed.

How to Fix UV Distortion

If the overlay reveals significant yellow or red areas on your mesh, use these techniques to resolve the distortion:

  • Add More Seams: Select edges on your 3D mesh in Edit Mode, right-click, and select Mark Seam. Adding seams allows complex geometry to unwrap flatter.
  • Re-unwrap the Mesh: After placing new seams, select all faces (A) and press U > Unwrap to recalculate the UV map.
  • Use Minimize Stretch: In the UV Editor, select all UV vertices, click UV in the top menu, and select Minimize Stretch (or press Ctrl + V). Scroll your mouse wheel or adjust the tool settings to reduce distortion interactively.
  • Relax UVs: Select problematic UV islands and use the Relax brush in the UV Sculpt tools to manually smooth out vertex tension.