trackBuilder/multiTrackMerger - Track Intersection Merging

Reference for extensions/util/trackBuilder/multiTrackMerger.lua. Creates procedural meshes at intersection points where multiple track segments meet, filling the gaps with bezier-interpolated surfaces.

Exports

Internals

• Bezier edge generation: bezierEdge(a, b, center) creates a cubic bezier curve between two track endpoints, using their orientation vectors as control point tangents. Interpolates bank, width, and pitch along the curve.
• Plate mesh generation: makePlateMesh(leftEdge, rightEdge, center, mat, bottom) creates a triangulated surface between two bezier edges and a center point. Generates both top and bottom faces.
• Center mesh: getCenterMesh(edges, mat) fills the center area of multi-way intersections (3+ segments) with plate meshes.
• Point coordinate system: Each bezier point gets nx/ny/nz orientation vectors computed from its final rotation quaternion.

How It Works

1. mergeMultiTrack receives a list of segment endpoints (with position, rotation, width, bank data).
2. Endpoints are sorted by angle around their centroid for correct winding order.
3. Bezier edges are computed between consecutive endpoints using bezierEdge.
4. For each edge, center and border meshes are generated using the same mesh generators as regular track segments.
5. For 3+ way intersections, additional fill meshes close the center gap.
6. All meshes are combined into a single ProceduralMesh object registered in MissionGroup.

-- Create an intersection between track endpoints
local segments = {
  {index = 5, sub = 1, segment = track[5], reverse = false},
  {index = 3, sub = 2, segment = track2[3], reverse = true},
}
local obj = merger.mergeMultiTrack(segments, 'track_editor_A_center', 'track_editor_A_border')

Additional Exports

• M.mergeMultiTrack - (undocumented)
• M.setMaterials - (undocumented)
• M.setReferences - (undocumented)