How to Relax UVs Using Sculpt Tools in Blender

Relaxing UV maps in Blender helps distribute texture coordinates evenly and reduce stretching on 3D models. While standard UV unwrapping tools offer basic relaxation, Blender’s UV Sculpt tools provide an intuitive, brush-based workflow to smooth out distortion directly inside the UV Editor. This step-by-step guide explains how to enable, configure, and use the Relax brush and other UV sculpting tools to clean up your UV islands.

1. Open the UV Editor and Enable UV Sculpting

  1. Switch to the UV Editing workspace at the top of the Blender window.
  2. In the 3D Viewport, select your 3D mesh, press Tab to enter Edit Mode, and press A to select all vertices so the UV layout appears in the UV Editor.
  3. In the UV Editor, open the UV menu from the top header and check UV Sculpt, or simply choose a sculpt brush tool from the toolbar on the left side of the UV Editor (press T if the toolbar is hidden).

2. Configure the Relax Brush Settings

  1. Select the Relax brush tool from the UV Editor toolbar.
  2. Adjust the primary brush properties using shortcuts or the Tool settings tab on the right side of the UV Editor:
    • Radius (F): Adjusts the size of the brush.
    • Strength (Shift + F): Controls the intensity of the relaxation effect per stroke.
  3. Choose the relaxation algorithm under the tool settings:
    • Laplacian: Smooths the vertices toward the center of neighboring points. Works well for uniform grids, though it can cause shrinking.
    • HC (Humphrey’s Classes): Preserves the overall volume and shape of the UV island while relaxing the internal vertices. This is ideal for organic meshes.

3. Apply the Relax Brush to Your UVs

  1. Click and drag the mouse over stretched or pinched areas in the UV Editor to relax the underlying vertices smoothly.
  2. To prevent the outer boundary of your UV island from shrinking inward while brushing, check the Lock Borders option in the brush settings toolbar.
  3. If you want specific vertices to remain stationary while relaxing surrounding areas, select those vertices and press P to pin them (they will display as red dots). When finished sculpting, press Alt + P to unpin them.

4. Utilize Complementary UV Sculpt Brushes

  • Grab Brush: Click and drag to manually push and align distorted UV regions without altering the rest of the island.
  • Pinch/Expand Brush: Pulls UV coordinates toward the center of the brush to condense high-density detail, or pushes them outward to expand tight areas.