Unreal Engine UV Editor: A Step-by-Step Guide to Unwrapping

What you’ll learn in this guide

Unreal Engine UV Editor combines a 2D workspace for editing a mesh’s UV coordinates with a 3D view that shows the result on the model. In this guide, you’ll learn how to open the editor, generate UVs automatically, edit seams and islands, pack UVs, and apply the result to a mesh. The goal is to make the texture space of a model created or imported in the engine easier to control.

UVs determine how a texture is mapped onto a model’s surface. Poorly distributed UVs can cause textures to look stretched or compressed. The 2D view lets you work with UV coordinates, while the 3D view shows how your edits affect the model.

Requirements and preparation

You’ll need a project with a mesh in the Unreal Engine editor. Epic’s documentation does not specify a particular Unreal Engine version or account requirement for using UV Editor, so this guide does not assume a required version number or account. Since the source documentation describes both UV Editor and Modeling Mode as beta, use these features with care, especially when preparing a project for release.

If Modeling Mode isn’t visible in the options, Epic’s guide recommends checking that the Modeling Tools Editor Mode plugin is enabled under Edit > Plugins. You can switch to Modeling Mode from the Select Mode dropdown or use the Shift+5 shortcut.

Step-by-step UV editing

1. Select a mesh and open UV Editor. You can use the UVs category in Modeling Mode, or right-click a mesh in the Level or in the Content Browser to open UV Editor. When the editor opens, it displays the imported mesh’s existing UV map. Meshes created in the engine have default UVs.

2. Get familiar with the workspace and views. The main interface areas are the toolbar, tools, 2D Viewport, and 3D Viewport. Edit UV islands in the 2D Viewport and see how they map onto the mesh in the 3D Viewport. In the 2D view, zoom using the middle mouse button and pan the grid by right-clicking. To focus on the selected UVs in the 3D view, press Alt+F while the view is active.

3. Create initial UVs or inspect the existing map. For a quick start, use the AutoUV tool. The documentation describes three methods: Patch Builder, UV Atlas, and XAtlas. Patch Builder is designed to support large models, including Nanite models, and is listed as the default option in the engine. UV Atlas aims to reduce stretching on organic objects but does not work on Linux. XAtlas is designed for lightmaps and mechanical meshes. Treat these as a starting point for editing, not as an automatic final solution.

4. Define seams if needed. To start manually, select the Seam tool. You can create seams by separating edges in either the 2D or 3D view; selecting at least two vertices creates a seam. Consider where the seams will appear on the model: you’ll usually want to place them where viewers are less likely to notice them. The Seam tool lets you switch between cutting and joining.

5. Split, join, or re-unwrap UV islands. Use the Split tool to separate a UV island. It can cut along edges, triangles, or connections called bowtie vertices. Use the Sew tool to reconnect two opposing edges. The selected edge is highlighted in red and its matching edge in green; joining them creates a new UV island. If existing UVs are stretched or compressed, the Unwrap tool can recalculate the coordinates. ExpMap is fast; Conformal reduces more distortion but is more costly on large islands. SpectralConformal can reduce distortion further, but takes longer to compute.

6. Pack the islands. The Layout tool can place UV islands in the 0–1 space or in existing UDIM layouts when Preserve UDIMs is enabled. Repack packs islands together without overlapping them. Stack places islands on top of one another, which can reduce repetition for islands that share the same texture design. Transform changes the scale and position of UVs while preserving their existing layout. Allow Flips in Repack can improve space usage, but check the result because it may cause issues in subsequent steps.

7. Check the texture display and apply the changes. In the Display tab, you can toggle the grid and rulers, and show the texture mapped to the UVs as a background. The background appears automatically in the 0–1 unit square; UDIMs must be configured to display it correctly in other tiles. Check the result in the 3D Viewport. Apply in the toolbar applies the UV changes to the original mesh; Save saves the UV map.

Common mistakes

Checking UVs only in the 2D view can make it easy to miss how the texture looks on the model. Seams on visible surfaces can also leave unwanted marks, so keep an eye on the 3D view as you edit. Don’t assume automatic unwrapping will produce a perfect result for every mesh: Epic describes AutoUV as useful for getting started with custom UV editing or for background objects that need a quick map.

When using Repack, check that the islands don’t overlap and that the Allow Flips setting suits the next steps in your workflow. For complex geometry with uneven distribution, SpectralConformal may reduce distortion, but it takes longer to compute. For simple, flat geometry, the different unwrapping methods may produce similar results.

Impact on architectural visualization workflows and next steps

Architects, interior designers, and visualization artists working with scene assets in Unreal Engine can use UV Editor to control texture placement directly in the engine. AutoUV can provide a quick starting point, especially for background assets. For visible surfaces, check seam placement, island layout, and how the texture appears on the 3D model. The documentation also notes that a mesh can have multiple UV Channels for lightmaps or different texture layers.

Tools in Modeling Mode often don’t apply changes immediately: the result is previewed first, then confirmed with Accept or discarded with Cancel. Don’t overlook this confirmation step when making modeling edits beyond UVs, either. The source documentation does not provide specific hardware requirements, pricing, or licensing terms; the beta warning should be taken into account during project delivery and release. In the next stage, you can work with textures and materials and inspect UV channels.

Sources and license

This guide was adapted into Turkish from Epic Games’ UV Editor in Unreal Engine and Modeling Mode in Unreal Engine documentation. The source records list both documents as license=free.