Import

Apollo Map Studio can load an existing base_map.bin file and restore it as an editable map.

Import a map

1. Click Import in the top-right toolbar
2. Either drag and drop a .bin file onto the drop zone, or click to open the file picker
3. The parser decodes the binary, converts all ENU coordinates back to WGS84, and populates the editor state

After import, the map behaves identically to one drawn from scratch — all elements are selectable, editable, and re-exportable.

What gets restored

Element	Restored fields
Lanes	centerline geometry, width (estimated from samples), speed limit, type, turn, direction, boundary types, predecessor/successor/neighbor IDs, junction ID
Junctions	polygon geometry
Crosswalks	polygon geometry
Stop signs	stop line geometry, type
Clear areas	polygon geometry
Speed bumps	position line geometry
Parking spaces	polygon geometry, heading
Signals	stop line geometry, signal type, position (midpoint of stop line)

Overlap objects

Overlap objects from the binary are not restored to the editor state — they are recomputed from scratch at export time. This ensures consistency if you modify any element after import.

Coordinate recovery

The import parser extracts the ENU origin from the map's header.projection.proj string:

+proj=tmerc +lat_0=<originLat> +lon_0=<originLon> +k=1 +ellps=WGS84 +no_defs

If the projection string is absent or malformed, the origin defaults to (0, 0). In that case, re-open Project Settings and correct the origin before exporting.

Width estimation

Apollo's base_map.bin stores left_sample and right_sample arrays (per-meter distances from centerline to each boundary). The import parser estimates the lane width as:

width = mean(left_sample[i].width + right_sample[i].width)

This gives an approximate uniform width. For lanes with varying width, the exported base_map.bin will use the constant estimated width for sampling.

Limitations

• Road proto is not restored — lane-to-road grouping (roadId) is lost on import. Lanes re-export each as their own road unless you manually set roadId in the Properties panel after import.
• sim_map.bin and routing_map.bin are not parsed — only base_map.bin is supported as import source.
• Subsignal geometry — the Subsignal locations within a signal are not restored (Apollo Map Studio treats a signal as a single point + stop line).