unilab.visualization.playback_session.SnapshotPlaybackSession

class unilab.visualization.playback_session.SnapshotPlaybackSession[source]

Bases: object

Cache physics snapshots during a trial; render them to video afterwards.

Parameters:

Methods

__init__(env, *[, frame_state_getter, ...])

clear()

Drop all cached snapshots and overlays (call between trials).

render_snapshots(*, output_video[, ...])

Render cached snapshots to output_video and return its path.

snapshot()

Cache one physics snapshot (and the current overlays, if configured).

Attributes

snapshots

The cached physics states, in capture order.
__init__(env, *, frame_state_getter=None, overlay_getter=None, render_spacing=None, width=1280, height=720, num_processes=8)[source]
Parameters:
__len__()[source]
Return type:

int

property snapshots: tuple[ndarray, ...]

The cached physics states, in capture order.

snapshot()[source]

Cache one physics snapshot (and the current overlays, if configured).

Return type:

ndarray

clear()[source]

Drop all cached snapshots and overlays (call between trials).

Return type:

None

render_snapshots(*, output_video, overlay_getter=None, camera=None, fps=None, on_frame=None)[source]

Render cached snapshots to output_video and return its path.

overlay_getter here is evaluated once per cached frame at render time and overrides the snapshot-time overlays captured through the constructor getter; prefer the constructor overlay_getter for state-coupled overlays. camera is normalized through CameraCfg.from_kwargs() (unknown keys fail closed). on_frame receives (frame_index, frame) after rendering and may return a modified frame. Returns None when the host cannot render off-screen (a warning is printed by the renderer).

Parameters:
Return type:

str | None