Advanced Usage

Mesh Distribution

The tool offers three distribution methods for placing meshes along the spline:

Single Distribution

When only one component is enabled, there is only one distribution possible - the same mesh is placed at every mesh placement position along the spline.

Round Robin Distribution

Cycles through available meshes in sequence, ensuring even distribution. This creates repeating patterns such as:

• Red, white, red, white barriers or flags
• Post, wire, post, wire for fence assemblies
• Light, dark, light, dark for alternating lamp posts

The pattern repeats consistently from start to end of the spline.

Random Distribution

Uses weight sliders and a random seed for probabilistic placement:

• Weight Normalization: The weights of each component’s weight slider are normalized to determine the probability of appearing
• Probability Calculation: Each component gets a chance to appear based on its normalized weight
• Random Seed: The random seed ensures reproducible patterns - the same seed will always generate the same distribution
• Sequential Population: Meshes are populated along the spline from start to end using the calculated probabilities

Example: With 3 components and weights of 0.8, 0.4, and 0.1:

• Component A (weight 0.8): ~62% chance, appears most frequently
• Component B (weight 0.4): ~31% chance, appears moderately
• Component C (weight 0.1): ~7% chance, appears rarely

In a spline with 100 mesh placement positions, you might see approximately 62 instances of Component A, 31 instances of Component B, and 7 instances of Component C, creating natural variation while maintaining the desired proportions.

This method is ideal for creating natural, varied arrangements while maintaining artistic control through weights and ensuring consistency through the random seed.

Jitter Controls

The Mesh Spline Tool includes tri-axial jitter controls (roll/pitch/yaw) for adding natural variation to mesh placement:

Jitter Workflow Approaches

Approach 1: Set Jitter Amplitude First

• Set Jitter Amplitude: Adjust the roll, pitch, and yaw sliders to set the overall amplitude of variation
• Fine-tune with Random Seed: Use the random seed slider to cycle through different variations without changing the amplitude
• Iterative Refinement: This approach allows the user to establish the “character” of the variation with the jitter sliders, then find the perfect variation using the random seed

Approach 2: Fix Random Seed First

• Set Random Seed: Choose a specific random seed value to lock in a particular variation pattern
• Adjust Individual Jitter: Fine-tune individual roll, pitch, or yaw sliders to achieve the desired effect
• Precise Control: Useful when the user wants to maintain a specific variation pattern while adjusting only certain aspects

Jitter Applications

• Small Values: Subtle natural variation for realistic placement
• Large Values: Dramatic variation for artistic or stylized effects
• Combined Approach: Mix different amplitudes across axes for complex variation patterns
• Selective Jitter: Use only specific axes (e.g., roll only) for targeted variation

Start/End Caps

Advanced cap usage allows for custom start and end treatments:

Custom Cap Meshes

• Start Cap Selection: Choose a specific mesh to appear at the beginning of the spline
• End Cap Selection: Choose a different mesh to appear at the end of the spline
• Orientation Control: Set the rotation and alignment of cap meshes

Cap Design Requirements

• Component Variations: Start and end caps should be special variations of the main components they cap
• Pivot Positioning: The pivot should be in the center rather than at the joining edge
• Consistent Scale: Caps should maintain the same scale as the main spline components

Common Usage Patterns

• Same Mesh, Different Rotation: The user will often use the same mesh for both start and end caps but with different rotations
• 180-Degree Difference: Start caps might have a pre-rotation value of 1 while end caps have a value of 3 (representing a 180-degree difference around the Z-axis)
• Mirrored Appearance: This creates a mirrored or symmetrical appearance at the spline endpoints

Cap Applications

• Fence End Posts: Use decorative end caps for fence assemblies
• Barrier Terminals: Place impact-absorbing caps at road barrier ends
• Pipeline Endings: Add valve or connection caps to pipe splines

Terraforming

The Mesh Spline Tool includes terraforming capabilities which automatically adjust the surrounding terrain to match the user’s spline design. This is useful for creating realistic infrastructure which properly integrates with the landscape.

How Terraforming Works

• Create and Edit the Spline: Design the spline with the desired elevation, banking, and width variations
• Access Terraforming Options: Go to the Terrain tab to find all terraforming controls
• Configure Parameters: Set the terraforming parameters to control how the terrain is modified
• Execute Terraforming: Click the “Terraform” button to perform the operation

Terraforming Parameters

Domain of Influence (DOI)

• Range: 0 to 500 meters
• Purpose: Defines how far away from the spline the terraforming operation will affect the terrain
• Usage: Larger values create wider terraforming areas, smaller values keep changes more localized

Terraform Margin

• Range: 1 to 20 meters
• Purpose: Creates a flat, smooth area around the spline edges before the terrain begins to fall off
• Behavior: The margin follows the plane of the spline, including banking and slope variations
• Effect: Ensures the immediate area around the spline has a clean, flat surface

Terraform Falloff

• Range: 1 to 5
• Purpose: Controls how quickly the modified terrain blends into the surrounding landscape
• Values:
  • 1: Very gradual, gentle blending
  • 3: Balanced falloff (recommended for most situations)
  • 5: Steep, abrupt blending for sharp terrain transitions

Noise Parameters

Noise Roughness

• Range: 0 to 1
• Purpose: Controls the amplitude of terrain variations (bump size)
• Usage:
  • 0: Smooth, clean terrain
  • 0.5: Moderate surface variation
  • 1: Maximum roughness with large bumps

Noise Scale

• Range: 0 to 1
• Purpose: Controls the frequency of terrain variations (bump density)
• Usage:
  • 0: Very fine, detailed surface texture
  • 0.5: Balanced surface detail
  • 1: Large, sparse surface variations

Note: The noise system automatically generates multiple layers of detail for natural-looking terrain variation.

Terraforming Process

• Terrain Analysis: The system analyzes the spline’s elevation, banking, and width
• Margin Creation: Creates a flat margin around the spline following the spline’s plane
• Falloff Application: Applies gradual terrain blending from the margin to the DOI boundary
• Noise Integration: Adds surface variations for realistic terrain appearance
• Final Blending: Smoothly integrates the modified terrain with the existing landscape

Performance Considerations

• Execution Time: Typically takes 2-7 seconds depending on spline length and DOI size
• Operation Type: Blocking operation - the interface will be unresponsive during execution
• Memory Usage: Larger DOI values require more memory for terrain calculations

Best Practices

• Iterative Workflow: Terraforming supports undo/redo, allowing the user to experiment and refine results
• Start with DOI: Begin by adjusting the Domain of Influence to get the overall terraforming area right
• Refine Margin: Once DOI is set, adjust the margin to ensure it doesn’t undercut the spline surface (this can happen with high falloff values)
• Margin Guidance: A margin value of 1m does not guarantee exactly 1m around the spline everywhere - it’s just a guide
• Add Detail: Finally, use noise parameters to add surface detail and variation
• Falloff Balance: Avoid values of 1 (too shallow) - 3-4 usually provides good results
• Noise Integration: Use noise for natural terrain features and realistic ground variation