Basic Usage

This section covers the core workflow for using the Road Spline Tool to create roads with terrain painting and edge blending.

Getting Started

Opening the Tool

1. In the World Editor, locate the mode bar at the top

2. Click the Road Spline mode button

3. The tool window will open with a row of buttons at the top

4. The first button is “Add New Road Spline”

Create a New Road Spline

1. Click “Add New Spline” in the tool window

2. The mouse cursor sphere on the map will change from red to purple

3. Left-click on the map to place nodes and draw the road path

4. Continue clicking to add more nodes - the road spline will appear as the user draws

Note: When the user creates a road spline, the tool automatically generates some default layers which are controlled with checkboxes. These include road edges, center paint lines, and light tire tread wear (one on each side of the road, so 2 total).

Basic Editing

Moving Nodes

• Mouse method: Click and drag nodes directly on the map

• Gizmo method: Press ALT to toggle the gizmo, then use the translation gizmo handles

Adjusting Road Width

1. Select a node on the road spline

2. Look for the rib handles (left and right controls at the node)

3. Drag the rib handles in or out to adjust the road width

4. Layers will move/scale proportionally

Node Editing

• Select node: Click on any node (it will be highlighted)

• Drag node: Click and drag nodes to move them around the map

• Adding new nodes: Hover over free space on the map to add nodes to either end of the spline (whichever is closer)

• Inserting nodes: Hover over the spline to see a highlight sphere and text hint - click to insert a node

• Delete node: Select a node and press DEL

Spline Operations

• Looping a spline: Drag the start or end node close to the other end - a hint line will appear with text markup. Hold SHIFT and release to create a loop

• Joining splines: Drag the start or end node of one spline onto the start or end node of another spline of the same tool type - a hint line will appear. Hold SHIFT and release to merge them into one spline

• Splitting splines: Select a node on the spline, then click the “Split” button under the spline list to divide the spline into two separate splines at that point

• Simplifying splines: Use the “Simplify” button to reduce the number of nodes to a minimum while preserving the core shape

• Flipping splines: Use the “Flip” button to reverse the order of nodes in the spline, effectively flipping the direction. This will also flip the road layers left to right

Auto-Generated Layers

Understanding Default Layers

1. Road Edges: Automatically generated edge lines for the road boundaries

2. Center Paint Lines: Default center line markings for lane separation

3. Light Tire Tread Wear: Subtle wear patterns on both sides of the road

4. Layer Control: Each default layer has a checkbox to enable/disable it

Managing Default Layers

1. Checkbox Controls: Use the checkboxes to include/exclude each default layer

2. Customization: These layers provide a starting point for road creation

3. Layer Properties: Default layers can be adjusted or replaced with custom layers

Adding Material Layers

Starting from Scratch

1. New road splines automatically come with default layers (road edges, center paint lines, tire tread wear)

2. To start completely fresh, remove all existing layers first:

   • Select each layer in the layers list
   • Click “Remove Layer” for each one
   • Or use the “Clear All Layers” button if available

3. This gives the user a clean slate to build the road from scratch

Building a Road

1. In the tool window, find the Layers section

2. Click “Add Layer” to create a new decalroad layer

3. Click the Select New Material button to open the Material Selector window

4. In the Material Selector window, browse the list of available materials

5. Use the search facility to find specific materials by name

6. Select the preferred road material (e.g., Asphalt) and close the Material Selector

7. The layer will appear in the layers list and be visible on the spline

8. The user can laterally offset the layer, change the properties, etc.

Terrain Painting

1. Open the Painting tab

2. Use the Switch Terrain Painting On/Off toggle button to enable terrain painting

3. Use the Paint Material slider (integer) to select the paint material from the map’s available materials

4. The selected material will be painted on the terrain along the road path

5. The Paint Margin slider will change the width of the painting relative to the spline to make it shrink/grow

6. Note that for long road splines, terrain painting can cause significant slowdown

Edge Blending

Blending Layers

1. Some materials are designed to transition smoothly between two materials (e.g., asphalt to grass)

2. These materials can be placed along the edges of the road and combined with terrain painting for seamless blending

3. In a layer, select a blending material (e.g., grass-to-asphalt transition, asphalt-to-dirt, etc.)

4. Set the Width to cover the transition area

5. Use Lateral Position to position the blend layer at the road edge

6. Use the Flip Lateral checkbox, if required, to make the transition go in the correct direction

Spline Management

Enabling/Disabling Splines

1. In the tool window, find the spline list

2. Use the enable/disable toggle for each spline

3. Disabled splines: No nodes visible, but content still shows

4. Enabled splines: Full interaction with nodes and editing

Recovery System

1. Polygon Selection: Use the polygon selection button in the tool to draw a selection area around decal roads

2. Scene Tree Selection: Multi-select compatible decal road objects in the scene tree, then right-click and choose “Convert to Road Spline”

3. Object Select: Use the object select tool, then right-click and choose “Convert to Road Spline”

4. The tool will add a new spline and estimate all properties including road width, layer settings, and terrain painting parameters

Profile Management

1. Save profile: Click the “Save Profile” button under the spline list to save the current spline’s properties to a JSON file

2. Load profile: Click the “Load Profile” button to load a previously saved profile from disk

3. Profile contents: Profiles contain spline properties (layer settings, materials, terrain painting, edge blending) but not the geometry itself

4. Copy profile: Use CTRL+C to copy the selected spline’s profile to the clipboard

5. Paste profile: Use CTRL+V to paste a copied profile to another spline, inheriting all properties while keeping the target’s geometry

Workflow Notes

• Test terrain painting early to see how it looks

• Disable terrain painting during heavy editing for better performance

• Use the gizmo (ALT key) for precise height and rotation control

• The auto-generated default layers can provide a starting point for road creation

Export to PNG Mask

The tool includes an “Export to PNG Mask” button in the top button row. This exports the entire tool session to a grayscale 16-bit PNG mask, useful for third-party software importing and exporting.

Next Steps

Once the user is comfortable with these basic workflows, they can explore:

• Using custom materials
• Complex material layering
• Custom edge blending/terrain painting setups
• Integration with Master Spline Tool