Follow the vessel in Google Earth¶

Google Earth Pro on the desktop and Liquid Galaxy installations accept ViewSync UDP packets that move the camera; the simulator can send them so that the view follows the vessel. The packet layout is on the ViewSync reference page.

Enable ViewSync in Google Earth¶

Google Earth listens for ViewSync packets only when configured to. Close Google Earth and edit its drivers.ini:

Platform	File
Windows	`%LOCALAPPDATA%\Google\GoogleEarth\drivers.ini`
macOS	`~/Library/Application Support/Google Earth/drivers.ini`
Linux	`~/.googleearth/drivers.ini`

Add or change the ViewSync section so that it receives, on the port you will send to:

[ViewSync]
sendEnabled = false
receiveEnabled = true
port = 42000
hostname =

Start Google Earth again. Liquid Galaxy installations already receive on their configured port; use that port and the address of the master node instead.

Send packets from the simulator¶

Add a UDP output with the viewsync encoding pointed at the machine running Google Earth. From the command line:

nmeasim run --udp 192.168.1.20:42000 --encoding viewsync

In the desktop application add a UDP output in File → Settings... → Outputs, set the address and port, and choose ViewSync as its Encoding. The ViewSync fields set the camera height above the vessel (500 m by default), its tilt (60 degrees, looking ahead along the heading) and roll. A profile carries the same settings:

{ "type": "udp", "address": "192.168.1.20", "port": 42000, "encoding": "viewsync",
  "period_ms": 200, "viewsync": { "camera_altitude_m": 800, "tilt_deg": 55 } }

Google Earth applies each packet as it arrives, so a short period (100 to 250 ms) gives a smooth flight. Sail a track to fly along a recorded route.

Check the packets without Google Earth¶

nmeasim run --stdout --encoding viewsync --quiet --duration 2 | python3 tools/check_viewsync_stream.py