anderscognite/flyover-reverse-engineering

Reversing Apple's 3D satellite mode

This is an attempt to reverse-engineer Flyover (= 3D satellite mode) from Apple Maps. Main goal is to document the results and to provide code that emerges.

Motivation

Noticed differences between Google Earth and Apple Flyover during previous project. Extreme example:

Google Earth	Apple Flyover

General

Data is stored in map tiles. These five tile styles are used for Flyover:

Type	Purpose	URL structure
C3M	Texture, Mesh, Transformation(, Animation)	🅐(?|&)style=15&v=⓿&region=❶&x=❷&y=❸&z=❹&h=❺
C3MM 1	Metadata	🅐(?|&)style=14&v=⓿&part=❻&region=❶
C3MM 2	Metadata	🅐(?|&)style=52&v=⓿&region=❶&x=❷&y=❸&z=❹&h=❺
DTM 1	Terrain/Surface/Elevation	🅐(?|&)style=16&v=⓿&region=❶&x=❷&y=❸&z=❹
DTM 2	Terrain/Surface/Elevation	🅐(?|&)style=17&v=⓿&size=❼&scale=❽&x=❷&y=❸&z=❹

• 🅐: URL prefix from resource manifest
• ⓿: Version from resource manifest or altitude manifest using region
• ❶: Region ID from altitude manifest
• ❷❸❹: Map tile numbers (tiled web map scheme)
• ❺: Height/altitude index. Probably from C3MM
• ❻: Incremental part number
• ❼❽: Size/scale. Not sure where its values come from

Resource hierarchy

ResourceManifest
└─ AltitudeManifest
   ├─ C3MM
   │  └─ C3M
   └─ DTM?

Focusing on C3M(M) for now. DTMs are just images with a footer; they're probably used for the grid that is displayed when Maps is loading.

Status

Here

Code

This repository is structured as follows:

Directory	Description
cmd	command line programs
pkg	most of the actual code
proto	protobuf files
scripts	additional scripts
vendor	dependencies

Install

Clone repo including submodules and install Go. Then edit config.json:

• automatically on macOS:
  • ./scripts/get_config_macos.sh > config.json
• or manually:
  • resourceManifestURL: from com.apple.GEO.plist or GeoServices binary
  • tokenP1: from GeoServices binary (function: GEOURLAuthenticationGenerateURL)

Command line programs

Here are some independent command line programs that use code from pkg:

Export OBJ (proof of concept, inefficient)

This exports Santa Monica Pier to ./export:

go run cmd/poc-export-obj/main.go

Authenticate URLs

This authenticates a URL using parameters from config.json:

go run cmd/auth/main.go [url]

Parse C3M file

This parses a C3M v3 file, decompresses meshes, reads JPEG textures and produces a struct that contains a textured 3d model:

go run cmd/parse-c3m/main.go [file]

Parse C3MM file (work in progress)

go run cmd/parse-c3mm/main.go [file]

Files on macOS

• ~/Library/Preferences/com.apple.GEO.plist
  • last resource manifest url
• ~/Library/Caches/GeoServices/Resources/altitude-*.xml
  • defines regions for c3m urls
  • altitude-*.xml url in resource manifest
• ~/Library/Containers/com.apple.geod/Data/Library/Caches/com.apple.geod/MapTiles/MapTiles.sqlitedb
  • local map tile cache
• /System/Library/PrivateFrameworks/GeoServices.framework/GeoServices
  • resource manifest base url, networking, caching, authentication
• /System/Library/PrivateFrameworks/VectorKit.framework/VectorKit
  • parsers, decoders
• /System/Library/PrivateFrameworks/GeoServices.framework/XPCServices/com.apple.geod.xpc
  • loads GeoServices
• /Applications/Maps.app/Contents/MacOS/Maps
  • loads VectorKit

Important

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.