Dekal adds box-projector decals to Blender 4.2 and newer. Each decal is an Empty whose box paints onto any surface inside it. The projection happens in the material, so there are no decal planes, no shrinkwrap and no z-fighting. Decals work in Cycles and EEVEE, and one click sends the scene to Unreal Engine 5 with every decal as a native, editable decal actor.

Install

1. Edit › Preferences › Get Extensions › Install from Disk…, then choose dekal-.zip.
2. Open the 3D Viewport sidebar (N) and the Decals tab.

Your first decal

1. Pick a decal in the Place box. Filter by category with the dropdown above the thumbnails. The bundled library has 43 presets: eight procedural starters and 35 CC0 decals and atlas sets from ambientCG. You can also choose None and load your own image.
2. Click Add Decal, then click a surface.
   • Shift+click keeps placing.
   • The mouse wheel scales the decal.
   • Esc or right-click finishes.
3. Move, rotate and scale the projector like any object. The decal follows live.

The clicked object is prepared automatically: its materials get one DCL_Surface node, and the object is put on Decal Layer 0. To prepare objects yourself, select them and click Prepare Receivers. Remove (the X button) restores the original material wiring exactly.

The projector

• The cube is the projection volume. The decal projects along the box's local −Z axis, shown by the arrow.
• X and Y scale set the decal size. Z scale sets the projection depth.
• The image is previewed on the top face of the box. Turn this off with Previews.

Decal settings

Displacement depends on the material's Settings › Displacement:

• Bump Only (the default): decal displacement shades as bump, and is cheap.
• Displacement Only or Both: real height.

Atlas Region picks a rectangle of the source images (X, Y, width, height in 0–1), so one texture sheet can serve many decals.

Decal layers

Each decal has a layer from 0 to 31. An object receives a layer when it has the custom property dcl_layer_ = 1.0. Use layers to keep decals off objects that share a material.

Library

• Apply Preset loads the selected preset onto the active decal.
• Save as Preset writes the active decal's maps and settings into a library folder.
• Add your own library folders in Preferences › Add-ons › Dekal.
• A preset is a folder with a decal.json file and its maps.
• Atlas sets (leaves, graffiti, screws, tape and so on) are one sheet with many items. Each placement picks one item at random and sizes the decal to it. Change the item afterwards with Atlas Region.
• Presets without an opacity map (most leaks, grime and wear) use the Multiply blend.
• The refresh button next to the category rescans the library folders after you add presets on disk.
• The ambientCG decals are CC0 1.0 (ambientcg.com). Use them anywhere, including commercial work.

Flatten

Select decals and choose Flatten Selected Decals. Their effect is baked into images on each receiving material, and the decals switch off. Unflatten brings them back exactly.

Flatten covers base color, roughness and normal. Displacement stays live. A material shared by several objects must be made single-user first.

Unreal Engine 5

Dekal brings your scene into Unreal Engine 5.3 or newer with one click. Meshes keep their own materials and textures, and every decal becomes a real Unreal decal actor that you can still move and edit. Nothing is baked.

First time: set up your Unreal project

Do this once per Unreal project:

1. In Blender, open Decals › Unreal Engine › First-Time Setup and click Set Up Unreal Project.

2. Pick your project's .uproject file. Dekal then:

   • installs its small Unreal plugin, which adds Tools › Import Dekal Scene…;
   • enables Unreal's USD Importer;
   • switches on Python remote execution, which lets Blender talk to the editor.

   It backs up the files it changes as .dekal.bak.

3. Restart Unreal and open the project.

Send to Unreal

With your project open in Unreal, click Send to Unreal in Blender's Unreal Engine panel.

• The status line under the button shows which Unreal editor Blender can reach. Click the refresh button to check again.
• Whole Scene sends every visible object; Selected sends only the selected ones.
• Blender exports the scene, then Unreal imports it. Unreal shows a progress bar, and Blender's status bar counts the seconds.
• The first import of a big scene takes a minute or two while Unreal compiles shaders.

In Unreal, the objects land in the Outliner folder Dekal › , with the decals in its Decals subfolder. The assets are in Content › Dekal › . Sending again replaces what the last send placed; it never duplicates.

Without a running editor: export to a folder

Open Export to Folder, choose a folder and click Export. The folder gets the scene as a .usd file, its textures and the decal textures. In Unreal, choose Tools › Import Dekal Scene… and pick the .usd file. Projects without the Dekal plugin can run import_dekal_scene.py from the export folder with File › Execute Python Script… instead.

Other export types in the same panel: