Topology
Apollo Map Studio derives lane topology fields from geometry rather than relying on hand-filled IDs. mapStore.addEntity / updateEntity / removeEntity triggers reconcileLaneTopologyIncremental for the affected set; the import/export worker runs the full reconcileLaneTopology.
Fields
From src/types/apollo.ts:118-164:
| Field | Geometry rule | | ------------------------- | -------------------------------------------------------------- | -------- | ----- | | predecessorIds | start point coincides with another lane's end (within epsilon) | | successorIds | end point coincides with another lane's start | | selfReverseLaneIds | central curves overlap, headings opposite | | leftNeighborForwardIds | left side, | Δheading | < 90° | | rightNeighborForwardIds | right side, same direction | | leftNeighborReverseIds | left side, | Δheading | > 90° | | rightNeighborReverseIds | right side, opposite direction | | junctionId | both endpoints inside a junction polygon |
Derivation rules
Predecessor / successor
Endpoints within ~1e-6 deg (~11 cm) on the WGS84 sphere are considered coincident. The reconcile pass writes both A.successorIds += B and B.predecessorIds += A.
Self-reverse
selfReverseLaneIds covers Apollo's "two-lane bidirectional segment" pattern where two lanes share the same geometry but point in opposite directions. The reconcile detects this by sampling central-curve points and verifying near-identical positions plus opposite heading.
Neighbour classification
For each candidate pair the reconcile compares the lane heading (atan2 of first→last centreline delta). |Δheading| < 90° ⇒ same direction; > 90° ⇒ reverse. Side (left/right) is the cross product of heading and the centre-to-centre vector at the closest pair of points.
Junction membership
Both central_curve endpoints are tested with point-in-polygon against every junction.polygon. Both-inside ⇒ junctionId = junction.id.
Steps
Automatic derivation
Just draw, move, or delete; topology updates incrementally.
Connect Lanes mode
ToolStrip C (connectLanes action) toggles a "click two lanes to connect" mode for cases where geometry alone doesn't capture intended succession (merge lanes, virtual links).
Inspector references
Select a lane → right-side Inspector lists every *Ids array as clickable references (LaneRefList.tsx). Click any ID to jump.
Options table
| Field | Type | Source | Notes | | ------------------------- | -------------- | ----------------- | --------------------------------------------------------- | -------- | ----- | | predecessorIds | string[] | derived + Connect | written bidirectionally | | successorIds | string[] | derived + Connect | written bidirectionally | | selfReverseLaneIds | string[] | derived | overlap + reverse | | leftNeighborForwardIds | string[] | derived | | Δheading | < 90° | | rightNeighborForwardIds | string[] | derived | same direction | | leftNeighborReverseIds | string[] | derived | | Δheading | > 90° | | rightNeighborReverseIds | string[] | derived | opposite direction | | junctionId | string\|null | derived | both endpoints inside polygon | | overlapIds | string[] | reconcileOverlaps | see Topology and junctions |
Shortcut cheatsheet
| Action | Key / Mouse | Notes |
|---|---|---|
| Connect mode toggle | C | connectLanes action |
| Exit Connect | C again / Esc | toggle off |
| Jump to reference | click in inspector list | LaneRefList |
| Select lane | click central curve | SELECT_ENTITY |
Troubleshooting
Aligned endpoints but no successor
Endpoint distance exceeds epsilon. Confirm snap actually pulled the endpoints together.
Neighbour written on wrong side
LaneEntity.direction is wrong; reconcile uses central-curve heading. Fix direction first.
Stale predecessor after delete
removeEntity should trigger incremental reconcile. If stale, check the worker incremental path.
Connect mode shows no preview line
Current implementation writes IDs only; geometry is unchanged. Cold layer renders on next frame.
dreamview reports orphan lane
Reconcile doesn't manage road.section.laneIds — that's the LayerTree's responsibility.
Source links
src/types/apollo.ts:118-164src/core/elements/derive/src/io/apolloIO.worker.tssrc/components/layout/panels/LaneRefList.tsxsrc/hooks/mapEventRouter/connectMode.ts
See also
Contributors
kent