Landscape Expressions

Expressions for creating materials to be applied to Landscape terrains.

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LandscapeLayerBlend

The LandscapeLayerBlend node enables you to blend together multiple Textures or Material networks so that they can be used as Landscape layers. The LandscapeLayerBlend uses an array to store information about the Landscape layers. To add layers to this array, select the plus sign icon.

Layer_Blend_arrayelements.png

When you add multiple layers to the LandscapeLayerBlend node, the Layer Names populate in the LandscapeLayerBlend node.

LandscapeLayerBlend Mode

Number

Property

Description

1

Layers

The list of layers the node contains. You can add layers by clicking the plus icon (Plus Sign).

2

Additional Layers

These are what additional layers look like when they are collapsed.

3

Layer Name

The unique name that you give the layer. The Layer Name corresponds to the layer name used in Paint mode in the Landscape tool window.

4

Blend Type

Either LB_AlphaBlend, LB_HeightBlend, or LB_WeightBlend. See Landscape Layer Blend Types on this page.

5

Preview Weight

This is the weight value for the layer to preview the blending in the Material Editor.

6

Const Layer Input

This is for supplying a numeric value as a color to use in case you do not want to use a texture. This is mainly used for debugging a layer if there is an issue.

7

Const Height Input

This is for supplying a numeric value as a height in case you do not want to use a texture.

The following table details the Layer Blend node inputs and outputs.

layer_blend_node.png

Number

Item

Description

1

Layer *LayerName

Each layer adds an input for the layer to blend together. This input is only available after layers are added and named in the Details panel.

2

Height *LayerName

This is where you supply a height map to blend with. This input is only visible on layers that have their Blend Type property set to LB_HeightBlend.

3

Unlabeled Output

The result of the layers blended together.

Blending Layers

When using certain combinations of layer blend modes you could end up with black spots all over your Landscape where different layers meet. This problem is especially prevalent when using the LB_HeightBlend mode for multiple Landscape layers. LB_HeightBlend works by modulating the blend factor, or weight, for the layer using the specified height value. When you have multiple layers painted on an area and they all are set to LB_HeightBlend, it is possible that all the layers painted in a particular area will simultaneously have a 0 height value, so the desired blend factor for each layer becomes 0.

Because there is no implicit or explicit ordering, the result will be black spots because no layers will have any contribution to that area. The situation is worse when you are blending a Normal map, because it results in a Normal value of (0,0,0) which is not valid and will cause rendering problems with the lighting. The solution to this problem is to use LB_AlphaBlend for one of the layers like in the example below.

In the left image, all layers are LB_HeightBlend, causing some areas to be black. On the right, the red "1" layer has been changed to use LB_AlphaBlend, which solves the problem.

LB_HeightBlend Problem

Below is an example of the properties of the Landscape Layer Blend node for all the layers being blended together. Make sure to note how the Soil layer has its blend mode set to LB_AlphaBlend while the other layers have theirs set to LB_HeightBlend. This is to stop the issue mentioned above (having black spots where layers meet) from happening.

Layer Blend Properties

If you need to delete a layer, click the drop-down arrow to the right of the layer's element number to open the menu, and select Delete.

Delete Layer

LandscapeLayerCoords

The LandscapeLayerCoords node generates UV coordinates that can be used to map Material networks to Landscape terrains.

LandscapeLayerCoords Node

Number

Property

Description

1

Mapping Type

The ELandscapeCoordMappingType that specifies the orientation to use when mapping the Material (or network) to the Landscape.

2

Custom UVType

The mapping place to use on the terrain. The CustomUVType outputs the UV coordinates to map the Material to the Landscape based on the given property values.

3

Mapping Scale

Applies uniform scaling to the UV coordinates.

4

Mapping Rotation

Applies the rotation, in degrees, to the UV coordinates.

5

Mapping Pan [U]

Applies the offset in the [U] direction to the UV coordinates.

6

Mapping Pan [V]

Applies the offset in the [V] direction to the UV coordinates.

7

Unlabeled Output

Outputs the UV coordinates to map the material to the Landscape based on the given property values.

LandscapeLayerSwitch

The LandscapeLayerSwitch node allows you to exclude some Material operations when a particular layer is not contributing to a region of the Landscape. This allows you to optimize your Material by removing calculations that are not necessary when a particular layer's weight is zero.

LandscapeLayerSwitch Node

Number

Property

Description

1

Parameter Name

The unique name that you give to the parameter.

2

Preview Used

If checked, uses a preview.

3

LayerUsed

When the layer specified in the node's properties is in use by the current region of the Landscape.

4

LayerNotUsed

When the layer is not used by the current region of the Landscape and has a weight of zero.

5

Unlabeled Output

Either the LayerUsed or LayerNotUsed inputs, depending on whether or not the layer contributes to the particular region of the Landscape.

LandscapeLayerWeight

The LandscapeLayerWeight expression allows Material networks to be blended based on the weight for the associated layer obtained from the Landscape the Material.The weight for this layer is used as the alpha value for blending the two input networks.

LandscapeLayerWeight Node

Number

Property

Description

1

Parameter Name

The unique name that you give to the parameter.

2

Preview Weight

The weight to use for preview purposes in the Material Editor.

3

Const Base

You can specify a base color here that you would like for your Landscape to have

4

Base

The network to blend this layer with. This is generally the result of any previous layer blending, but can be empty if this is the first layer.

5

Layer

The network to blend together to create this layer.

6

Unlabeled Output

Outputs the result of the blending between the Base and Layer inputs based on the layer weights of the layers involved.

LandscapeVisibilityMask

The LandscapeVisibilityMask node removes visible parts of your Landscape, so you can create holes in your landscape to, for example, create caves.

LandscapeVisibilityMask Node

Number

Property

Description

1

Unlabeled Output

Outputs the visibility mask properties.

Make sure the output is connected to the Opacity Mask slot of your Material and that the Materials Blend Mode is set to Masked. Otherwise the node may not work correctly.

layer_visibility_mask_opacitymask.png

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