Tutorial: build a flight tracker¶

Tutorial. Target: a viewer that animates an aircraft along a sampled route, with a ground path, a trailing flight line, and a camera that follows. You should end up with a reusable pattern for any time-dynamic entity.

Just want a single globe?

See How to build your first globe — the tutorial assumes you have a working Viewer already.

This tutorial builds one file, flight_tracker.py, step by step. Each section adds one piece; the final script is complete and runnable.

1. Create the viewer and its clock¶

The flight runs between 18:00 and 19:00 UTC. Set the clock to that window and make it loop so the animation repeats:

Think of the clock as a video player: start_time and stop_time are the clip's boundaries, current_time is the playhead, and multiplier is the playback speed.

import cesiumkit

viewer = cesiumkit.Viewer(
    title="Flight Tracker",
    should_animate=True,
    clock=cesiumkit.ClockConfig(
        start_time=cesiumkit.JulianDate.from_iso8601("2026-07-14T18:00:00Z"),
        stop_time=cesiumkit.JulianDate.from_iso8601("2026-07-14T19:00:00Z"),
        current_time=cesiumkit.JulianDate.from_iso8601("2026-07-14T18:00:00Z"),
        clock_range=cesiumkit.ClockRange.LOOP_STOP,
        multiplier=60,  # one simulated minute per real second
    ),
)

2. Define the route as sampled positions¶

A SampledPositionProperty interpolates between waypoints. Add one sample per leg of the flight; the altitude is in meters:

route = [
    ("18:00", -0.1276, 51.5072, 12000),  # London
    ("18:20", 2.3522, 48.8566, 11500),  # Paris
    ("18:40", 4.8952, 52.3702, 11000),  # Amsterdam
    ("19:00", -0.1276, 51.5072, 12000),  # back to London
]

position = cesiumkit.SampledPositionProperty(interpolation_degree=2)
for time_str, lon, lat, alt in route:
    position.add_sample(
        cesiumkit.JulianDate.from_iso8601(f"2026-07-14T{time_str}:00Z"),
        cesiumkit.Cartesian3.from_degrees(lon, lat, alt),
    )

3. Add the aircraft entity¶

The aircraft is a point with a label and a glowing trail. The path graphics draw the last 30 minutes of travel behind the aircraft:

viewer.add_entity(
    cesiumkit.Entity(
        id="aircraft-1",
        name="Flight A1",
        position=position,
        point=cesiumkit.PointGraphics(
            pixel_size=10,
            color=cesiumkit.Color.WHITE,
            outline_color=cesiumkit.Color.GOLD,
            outline_width=2,
        ),
        label=cesiumkit.LabelGraphics(
            text="A1",
            font="12px monospace",
            fill_color=cesiumkit.Color.GOLD,
            horizontal_origin=cesiumkit.HorizontalOrigin.LEFT,
            pixel_offset=cesiumkit.Cartesian2(x=12, y=0),
        ),
        path=cesiumkit.PathGraphics(
            width=3,
            lead_time=0,
            trail_time=1800,  # 30-minute trail, in seconds
            material=cesiumkit.PolylineGlowMaterial(
                color=cesiumkit.Color.GOLD,
                glow_power=0.15,
            ),
        ),
    )
)

4. Draw the route on the ground¶

A second entity traces the full route as a polyline at low altitude, so you can see the planned path while the aircraft moves:

ground_route = [cesiumkit.Cartesian3.from_degrees(lon, lat, 500) for _, lon, lat, _ in route]
viewer.add_entity(
    cesiumkit.Entity(
        name="Route",
        polyline=cesiumkit.PolylineGraphics(
            positions=ground_route,
            width=2,
            material=cesiumkit.Color.WHITE.with_alpha(0.6),
        ),
    )
)

5. Run it¶

viewer.show()  # Ctrl+C to stop the server

Save the file and run it:

python flight_tracker.py

You should see the aircraft fly the triangle route with a gold trail, the white route line on the ground, and the clock looping. To make the camera follow the aircraft, add

viewer.camera.fly_to_entities()

before show() and re-run.

What you built¶

A ClockConfig window with LOOP_STOP and a speed multiplier
A SampledPositionProperty interpolating a route
Entity path graphics for a trailing line
A polyline for the planned route

The same pattern handles any moving object — vehicles, ships, satellites — by swapping the waypoints and clock window.