Skidmark Manager

SkidmarkManager inspector.

Generates procedural skidmark meshes when wheels slip on surfaces.

Geometry

  • Min Distance: Distance a wheel must travel before creating a new skidmark segment.
  • Ground Offset: Height above ground at which skidmarks are drawn. Increase if skidmarks clip into terrain.
  • Texture Length Meters: Distance over which the skidmark texture repeats along the mark. The texture flows continuously down the strip rather than being stretched once per segment, so a long mark no longer looks like a row of identical stamps. Lower values tile faster; match this to the scale of the tread pattern in your material.

Lifetime

  • Max Tris Per Section: Number of triangles per section before creating a new mesh object.
  • Max Total Tris: Total triangle limit per wheel before oldest sections are destroyed.
  • Skidmark Destroy Time: Time in seconds before skidmarks are destroyed. Set to 0 to disable time-based destruction.
  • Skidmark Destroy Distance: Distance from vehicle at which skidmark sections are destroyed.

Appearance

  • Global Skidmark Intensity: Multiplier for overall skidmark darkness. Higher values produce darker marks.
  • Max Skidmark Alpha: Maximum alpha value for skidmark textures (0-1).
  • Lower Intensity Threshold: Minimum alpha threshold for generating skidmark geometry. Prevents faint marks.
  • Intensity Smoothing: Controls fade in/out speed. Higher values = faster response (10-20 recommended).
  • Simplified Shading: Cheap shading path for mobile and low-end targets. Drops specular response, procedural surface relief and edge breakup, leaving a flat textured mark. This sets a global shader keyword, so it applies to every skidmark in the scene rather than per vehicle.

Surface-based Skidmarks

Skidmark appearance is controlled by the active SurfacePreset assigned via GroundDetection. Each surface defines:

  • Skidmark material
  • Base intensity
  • Slip factor
  • Whether to draw skidmarks

Note: a surface preset with Draw Skidmarks enabled but no skidmark material assigned keeps whatever material the pooled skidmark object last used. Assign a material on every surface that draws marks, or turn drawing off for that surface.

Skidmark section of AsphaltTireFrictionPreset.

Slip Detection

Skidmarks appear when wheel slip exceeds thresholds defined in VehicleController:

  • Longitudinal Slip Threshold: Forward/backward slip threshold
  • Lateral Slip Threshold: Sideways slip threshold

Intensity is calculated from slip magnitude, surface settings, and wheel load.