Road

Use the Road component to create paths in Lumberyard Editor. You can create roads that follow the curvature of existing terrain by applying a texture over the terrain texture. You can also use the Align heightmap feature with the Road component to shape the terrain to the height and curvature of the road you placed.

To enable the Road component, you must enable the Roads and Rivers gem. For more information, see Add modular features and assets with Gems.

The Road requires the Spline component to shape its path along the X, Y, and Z axes. After you place a road, you can edit the points in the road’s spline.

Note
You can rebuild roads at runtime by modifying the spline. However, this method can be slow. We recommended that you avoid modifying the spline continuously at runtime.

Topics

• Road Properties
• Creating a Road
• Modifying Road Width
• Setting Road Material Properties
• Using Roads to Modify Terrain
• Erasing Vegetation
• RoadRequestBus Interface
• RoadsAndRiversGeometryRequestsBus Interface

Road Properties

See the following Road properties:

Creating a Road

To create a road

1. Create an entity.

2. Add the Road component.

3. Add the Spline component.

   The Spline component defines the path and shape of the road. For information about how to add, remove, and edit individual points, see Spline.

The road is created with the default material defaultRoad. The Spline component defaults to the Linear Spline Type and contains four vertices (0, 1, 2, 3). For a road that curves smoothly, specify the Bezier Spline Type.

Modifying Road Width

You can modify the road’s width by adjusting the road’s Global width property. Adjusting this property modifies all the points on the road.

For more granular control over the road’s width, you can adjust individual points with the Per-Vertex Width Modifiers property.

To adjust the width of individual points

• In the Road component properties, enter a negative or positive number for the property that you want to modify.

  Negative numbers subtract from the Global width property, while positive numbers add to it. A value of 0 means that point is at global width.
  Example

  The global width of this road is 2, and the width at the selected point is set to 5. The total width at the selected point is 7.
  

Setting Road Material Properties

Roads are Decals placed along a spline. This makes the material setup of a road similar to that of decals.

The road material must use the Illum Shader and should also enable the Decal and Vertex Colors parameters in the Shader Generation Params.

To open the Material Editor

1. In Lumberyard Editor, choose Tools, Material Editor or press M.

2. Select the road material and expand the Shader Generation Params, and select the following parameters:
   Vertex Colors
   Activates a blend fadeout at each end of the road. This is a 100% to 0% fadeout over the length of the final step. The textures and alpha channel have no influence on the fadeout.
   Decal
   Enables alpha blending on the sides of the road, which comes from the diffuse texture’s alpha channel.

Example
In the left image, Vertex Colors is enabled. In the right image, the parameter is disabled.

Using Roads to Modify Terrain

You can use roads to modify the shape of the terrain.

To modify the terrain with roads

1. Create a road.

2. Manipulate the individual vertices to shape the road. For more information, see Spline.

3. In the Road component’s properties, under Terrain Editing, set the Border width. This parameter defines the width of the slope at the edges of the road.

4. Click Align heightmap.

Example
The following image shows a road that has been created and shaped, but not yet aligned.

Example
The following image shows the road and terrain after alignment with a Border width of 5.

Example
The following image shows the road and terrain after alignment with a Border width of 20.

Erasing Vegetation

You can erase vegetation around the road’s borders.

To erase vegetation

1. In the Road component’s properties, under Vegetation Editing, specify the Erase width. This parameter defines the amount of vegetation to erase at the road’s edges.

2. Specify the Erase variance. This parameter randomizes the removal of vegetation, so that the edge looks more natural.

Example
The following image shows the road with no vegetation erased.

Example
The following image shows the road with Erase width set to 0.

Example
The following image shows the road with Erase width set to 1 and Erase variance set to 5.

RoadRequestBus Interface

Use the following request functions with the RoadRequestBus EBus interface to communicate with other components of your game.

For more information about using the event bus (EBus) interface, see Working with the Event Bus (EBus) system.

RoadsAndRiversGeometryRequestsBus Interface

Use the following request functions with the RoadsAndRiversGeometryRequestsBus EBus interface to communicate with other components of your game.

For more information about using the event bus (EBus) interface, see Working with the Event Bus (EBus) system.