Styling

Every rendered object carries a satellite-layer style — its marker, name label, orbit path, and ground track. gmat-czml ships named presets and a small colour / width / glyph customization API over them. The default, sat-default, is a yellow dot with a white name label and a yellow orbit trail / ground track; an unflagged to_czml(trajectory) renders exactly that.

Presets

preset(name) resolves a named preset to a Style:

from gmat_czml import preset, to_czml

to_czml(trajectory, style=preset("sat-red")).save("orbit.czml")

Preset	Colour
sat-default	yellow
sat-red	red
sat-green	green
sat-magenta	magenta

The palette presets paint the marker, orbit trail, and ground track a single hue — for telling several objects apart in a multi-object scene — while keeping the default sizes, outline, and white label. An unknown name raises UnknownStyleError rather than falling back to the default. These are the same names the command line's --style flag offers.

The customization API

A Style is four element styles. Override any of them; an unset field keeps its sat-default value:

from gmat_czml import Style, PointStyle, LabelStyle, PathStyle, TrackStyle, to_czml

style = Style(
    marker=PointStyle(color=(0, 200, 255, 255), pixel_size=12.0),
    label=LabelStyle(color=(255, 255, 255, 255), font="13pt Helvetica"),
    path=PathStyle(color=(0, 200, 255, 255), width=3.0),
    track=TrackStyle(color=(255, 0, 128, 255), width=4.0),
)
to_czml(trajectory, style=style, ground_track=True).save("orbit.czml")

Element	Style	Fields
Marker — point	PointStyle	color, pixel_size, outline_color, outline_width
Marker — billboard	ImageBillboard	image, scale
Label	LabelStyle	color, font
Orbit path	PathStyle	color, width
Ground track	TrackStyle	color, width

Colours are RGBA tuples with channels in 0–255.

Image-billboard glyphs

The marker is a coloured point by default, but it can be an image billboard instead — a screen-facing image. Set the style's marker to an ImageBillboard with any image URI a Cesium client can load (an http(s) URL, or a self-contained data: URI):

from gmat_czml import Style, ImageBillboard, to_czml

style = Style(marker=ImageBillboard(image="https://example.com/satellite.png", scale=1.5))
to_czml(trajectory, style=style).save("orbit.czml")

The billboard replaces the coloured point. gmat-czml ships no asset pipeline, so the caller supplies the image.

Annotation layers

The maneuver, contact, and attitude annotations are separate layers, each with its own default look — orange burns, cyan ground links and observers, a translucent-cyan attitude box — and its own style field on Style:

Layer	Style	Fields
Maneuvers	ManeuverStyle	marker (PointStyle), label (LabelStyle), arc (LineStyle)
Contacts	ContactStyle	observer (PointStyle), label (LabelStyle), link (LineStyle)
Attitude	AttitudeStyle	box_fill_color, box_outline_color, box_outline_width

from gmat_czml import Style, ManeuverStyle, ContactStyle, PointStyle, LineStyle, to_czml

style = Style(
    maneuver=ManeuverStyle(
        marker=PointStyle(color=(200, 0, 0, 255)),
        arc=LineStyle(color=(200, 0, 0, 255), width=5.0),
    ),
    contact=ContactStyle(link=LineStyle(color=(0, 180, 0, 255), width=2.0)),
)
to_czml(trajectory, style=style, maneuvers=maneuvers).save("orbit.czml")

LineStyle (color, width) is the generic line style the burn arc and the line of sight reuse. The palette presets recolour only the satellite layer; the annotation layers keep their semantic defaults unless you override them.