Unreal Engine Landscape Grass: A guide to adding grass to paintable terrain

Unreal Engine’s official documentation explains how to set up the Grass system to add static mesh-based grass to a Landscape and control it with layers. This method uses Landscape Paint tools to specify where grass appears across virtual terrain. The documentation does not specify a particular Unreal Engine version, so the steps below are based on the Landscape workflow described in the sources.

1. Set up the Landscape and Grass Type

1. Create a Landscape. Open a new level, follow Modes › Landscape in the main toolbar, and select Create to add a Landscape Actor. The official quick-start guide adds the Open World Demo Collection pack to the project to use its sample meshes and textures. This pack is not a requirement for the Grass system; it provides the sample assets used in the guide.

2. Create a Landscape Grass Type asset. Right-click in the Content Browser and select Foliage › Landscape Grass Type. Open the asset you created and add a new entry to the Grass Varieties array. In the sample setup, SM_FieldGrass_01 is assigned to the Grass Mesh field.

3. Set up grass placement. The example sets Grass Density to 400.0 for a dense grass look and enables Use Grid, Random Rotation, and Align to Surface. These are settings from the example, not mandatory or ideal values for every project. Random Rotation helps prevent the mesh from always facing the same direction, while Align to Surface helps the mesh conform to the Landscape surface.

2. Set up the material layers

1. Define the material and layers. Create a new Material and add a Landscape Layer Blend node in the Material Editor. The example creates two layers, Grass and Rock, and sets each Preview Weight to 1.0. Preview Weight is used for the preview in the material editor; it does not determine which layer is painted on the terrain.

2. Connect texture samples to the layers. The quick-start example connects the T_GDC_Grass01_D_NoisyAlpha texture to the Grass input and T_AlpinePatch001_D_alt_R to the Rock input, then connects the Layer Blend output to the Base Color input of the main material node. You can use different textures in your own project; the basic approach shown in the sources is to combine each layer’s appearance through a separate input.

3. Connect the Grass Type to the material. Add Landscape Layer Sample and Landscape Grass Output nodes to the Material Graph. Enter Grass in the Layer Sample node’s Parameter Name field and connect its output to Grass Output. Landscape Grass Output enables Landscape Grass Type generation on the Landscape based on the material layer. Then, in the Landscape Grass Type asset, assign this asset to the Grass Type option in the Material section. Apply and save the material.

3. Paint layers on the Landscape

1. Assign the material to the Landscape. Select the Landscape Actor in the viewport. Assign the material you prepared in the Landscape Material field of the Details panel. Then switch to the Paint tab via Modes › Landscape.

2. Create Target Layer information. In the Target Layers section, create Layer Info for both Grass and Rock. The example documentation uses Weight-Blended Layer (normal) as the layer type. These assets allow the Landscape to store paint weights. The official Landscape material documentation also emphasizes that a paintable layer must be associated with a Landscape Layer Info asset.

3. Paint the grass areas. Select the Grass Target Layer and hold down the left mouse button in the viewport to apply grass to the areas you want. To remove grass or apply the Rock texture to an area, select the Rock layer and paint in the same way. Brush Size and Tool Strength help control the area and effect of the paint.

4. How this fits into architectural visualization workflows

This method is useful for architecture and archviz teams that want to generate grass meshes on selected Landscape layers instead of covering the terrain with a single surface texture. Grass boundaries can be visually adjusted by painting with the rock texture, while the layered material approach lets different surfaces coexist on the same Landscape. This workflow can benefit anyone who wants to control within the scene where grass is concentrated, particularly for exterior visualizations.

The documentation does not specify requirements for a particular graphics card or amount of memory. However, the quick-start document notes that painting dense grass can cause the editor to stop responding, depending on the power of the development computer. For this reason, lowering Grass Density while working and raising it again for the final look is the practical measure suggested in the source. The documents provide no information about licensing, pricing, or compatibility across versions, so these should be verified separately for your project.

Common mistakes

• Trying to use the Grass system on an Actor other than a Landscape Terrain Actor. According to the official documentation, the system does not work with other Actor types.

• Not matching the material layer name with the Target Layer name in Landscape Paint. Landscape Layer Sample reads the weight of the target layer you specify; if there is no matching layer, its weight is treated as zero.

• Starting to paint without creating Layer Info for a layer. A paintable layer must be associated with a Layer Info asset.

• Keeping density high while painting. If the editor slows down temporarily, lower Grass Density while working and restore the target value afterward.

This setup provides the basic method for pairing static mesh grass with Landscape layers. The sample asset names and density value are from the example in the official quick-start guide; different meshes and layers can be used in a production scene to suit its needs.