| name | czml-clock |
| description | CZML document-level clock controlling the viewer's timeline: start/stop interval, current time, playback multiplier, and looping behavior. Use when the intent mentions a clock, timeline, playback speed, looping, or specific start/stop times for the whole scene. |
CZML Document Clock
- The "document" packet (always the first packet) MAY carry a "clock":
{ "interval": "<ISO8601 start>/<ISO8601 end>", "currentTime": "<ISO8601>", "multiplier": <number>, "range": "LOOP_STOP" | "CLAMPED" | "UNBOUNDED", "step": "SYSTEM_CLOCK_MULTIPLIER" | "SYSTEM_CLOCK" | "TICK_DEPENDENT" } to populate the
viewer's timeline for time-dynamic scenes.
- Whenever the intent specifies playback behavior (a start/stop time, a time multiplier, or
looping), you MUST add this "clock" object to the document packet with exactly those values —
do not omit it.
- "range": "LOOP_STOP" loops back to the interval start when it reaches the end; "CLAMPED" holds
at the end time; "UNBOUNDED" keeps advancing past the end.
- "step": "SYSTEM_CLOCK_MULTIPLIER" (the default) advances "currentTime" by "multiplier" times the
elapsed real (wall-clock) time between ticks — use this unless the intent asks for a different
stepping mode.
Example: named document metadata with a clock and one entity
[
{
"id": "document",
"name": "Vehicle Tracking",
"version": "1.0",
"clock": {
"interval": "2012-03-15T10:00:00Z/2012-03-16T10:00:00Z",
"currentTime": "2012-03-15T10:00:00Z",
"multiplier": 60,
"range": "LOOP_STOP",
"step": "SYSTEM_CLOCK_MULTIPLIER"
}
},
{
"id": "pt-1",
"position": { "cartographicDegrees": [5, 15, 0] },
"point": { "pixelSize": 10, "color": { "rgba": [255, 255, 255, 255] } }
}
]