Geo Pacenotes

Measures pacenote corner geometry by fitting circles to driveline points. Calculates corner severity, direction, radius, arc length, and fit quality. Provides debug visualization with 3D arc prisms.

Exports

How It Works

Measurement Modes

Single circle (default): Fits one circle through CS, halfpoint, and CE positions.

Two circles (intensity variation): Splits the corner at a percentage of total path length, fits separate circles to each segment. Used for compound corners.

Auto-Selection (autoSelectBestIntensityVariation)

1. Tests single-circle fit first - if fit quality ≤ 0.009, uses single circle
2. Otherwise tests all intensity variation options (none, 50%)
3. Selects the option with lowest average fit quality (normalized RMSE)
4. pn.intensityVariationAuto controls whether auto-selection runs (default: true)

Circle Fitting

Uses circle2DFrom3Points() from road architect utilities for 2D circle calculation, then calculates:

• Radius/diameter: from center to first point
• Arc distance: angle × radius
• Fit quality: normalized RMSE of all points' distances from the circle (lower = better)
  • < 0.05 = excellent, 0.05-0.15 = good, > 0.15 = poor/compound

Corner Severity

After measurement, calculateAndStoreSeverityDirection():

1. Finds nearest severity entry by diameter from text compositor config
2. Validates hairpin classification (requires ≥45% of circumference)
3. Detects direction via cross product (left/right/straight)
4. Calculates diameter change between corners (opening/tightening)

Measurement Data Structure

pn.measurements = {
  corner1 = {
    center = vec3(...), radius = 25, diameter = 50,
    arcDistance = 40, angleDegrees = 92,
    straightLineDistance = 35, fitQuality = 0.03,
    pointsLength = 42, p1 = vec3(...), p2 = vec3(...), p3 = vec3(...),
    severity = { value = 3, ... }, direction = "left"
  },
  corner2 = { ... },  -- nil for single circle
  splitPoint = vec3(...),
  totalPointsLength = 80,
  diameterChange = { change = 10, changePercent = 20, isOpening = true, isTightening = false }
}

Debug Visualization

Draws 3D arc prisms, radius lines, and text labels showing length, diameter, angle, and fit quality using debugDrawer:drawSquarePrism().

local geoPacenotes = require('/lua/ge/extensions/gameplay/rally/snaproad/geoPacenotes')
geoPacenotes.measurePartition(pacenote, focusPoints)
-- Results stored in pacenote.measurements

See Also

• normals - Snaproad Normal Vector Calculations - Related reference
• Gameplay Systems Guide - Guide