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    【Blender】UV Mapping for Beginners: Texture Placement Basics and Troubleshooting

    Created: 2025-12-06Last updated: 2026-01-15

    UV unwrapping basics for texturing 3D models. Covers seam placement, unwrapping, and verifying results with checker maps

    Overview

    To apply textures (images) to a 3D model, you need to perform "UV mapping." UV mapping is the process of unfolding a 3D shape into 2D and defining which part of the texture corresponds to which part of the model. This article covers everything from UV mapping basics to practical techniques.

    What is UV Mapping?

    UV mapping example: UV layout on left, 3D model on right

    "UV" refers to coordinates on the texture image (U and V are used because X, Y, and Z are already used for 3D space coordinates).

    Think of it like:

    • 3D model = Gift box
    • UV mapping = Blueprint for wrapping the box
    • Texture = Wrapping paper design

    Poor UV mapping causes textures to stretch, distort, or appear in unintended positions.

    Opening the UV Editor

    1. Select the "UV Editing" workspace at the top
    2. Or in any area, "Editor Type" → "UV Editor"

    The UV Editor appears on the left, 3D viewport on the right.

    What are Seams?

    Seams are the "cut lines" for unfolding a 3D model into 2D.

    Think of it like deciding where to cut when flattening a cardboard box.

    Seam example: red lines indicate the seams (cut lines)

    Creating Seams

    1. Enter Edit Mode (Tab)
    2. Switch to Edge Select mode (2)
    3. Select the edges to cut
    4. Ctrl + E → "Mark Seam"

    Seam edges display in red.

    How to UV Unwrap

    After setting seams, unwrap the UVs.

    Basic Unwrap

    1. In Edit Mode, select all (A)
    2. Press U → "Unwrap" (In Blender 4.5: "Unwrap Angle Based")

    The unwrapped UV map appears in the UV Editor.

    UV unwrap result: model unfolded into 2D along the seams

    Editing UVs

    You can edit UV islands (unwrapped parts) in the UV Editor.

    Basic Operations

    • G: Move
    • R: Rotate
    • S: Scale
    • L: Select island
    • P: Pin (lock selected vertices in place)

    Pinning

    Pinning locks specific vertices in place during UV editing. Pinned vertices won't move when re-unwrapping.

    • Pin: Select vertices and press P
    • Unpin: Alt + P

    Pin the areas you want to keep fixed, then re-unwrap. Other vertices will unfold relative to the pinned positions.

    Checking Textures

    Methods to verify UV mapping is correct.

    Using a Checker Texture

    Simply click the "Checker Map" button in the "TexTools" panel in the UV Editor sidebar to display a checker pattern.

    TexTools Checker Map button
    Checker map applied: uniform pattern indicates successful UV mapping

    If the checker pattern isn't distorted, UV mapping succeeded. If you see distortion, reconsider seam placement or manually adjust the affected areas in the UV Editor.

    Using Mirror Modifier with UVs

    When using a Mirror Modifier, you can also mirror the UVs symmetrically.

    Preparation

    1. In the UV Editor, arrange UV islands to fit within half of the texture area (left or right half)
    UVs arranged in half the texture space

    Mirror U Setting

    1. Open the "Data" section of the Mirror Modifier and enable "Mirror U"
    Mirror Modifier Mirror U setting

    With this setting, UVs will automatically mirror when the modifier is applied. This allows efficient texture use for symmetrical models.

    Common Problems and Solutions

    Texture is Stretched

    • Cause: UV island proportions don't match the original mesh
    • Solution: Adjust the affected area in UV Editor, or re-unwrap

    Texture is Flipped

    • Cause: Face normals may be inverted
    • Solution: Select faces in 3D view → Alt + N → "Flip"

    Seams are Visible

    • Cause: Seam placement is in a noticeable location
    • Solution: Move seams to less visible areas (back side, natural folds, etc.)

    UVs are Overlapping

    • Cause: Multiple UV islands are in the same position
    • Solution: Ctrl + P to pack UVs, or manually move islands

    Rectify is Disabled (Grayed Out)

    • Cause: UV Sync Selection is enabled
    • Solution: Click the "UV Sync Selection" button in the top-left of the UV Editor header to turn it OFF
    Rectify is grayed out

    When UV Sync Selection is ON, selections in the 3D Viewport and UV Editor are synchronized. In this state, some UV editing features like Rectify are restricted.

    UV Sync Selection button location

    Click the icon with two overlapping squares in the top-left header to turn it OFF, and Rectify will become available.

    Rectify is now enabled

    Tips for Efficient UV Mapping

    1. Minimize seams: Too many creates more visible seams
    2. Place seams in hidden areas: For characters, use armpits, clothing seams, etc.
    3. Consider texture resolution: Make important areas larger in UV space
    4. Ensure padding: Leave space between islands to prevent bleeding

    Summary

    • UV Mapping: Unfolds 3D models into 2D to define texture coordinates
    • Seams: Specify where to cut for unfolding
    • Unwrap: Generates UVs according to seams
    • Smart UV Project: Creates UVs quickly and automatically

    UV mapping may feel difficult at first, but the intuition develops with practice.