scene.recorder.FrameRecorder
scene.recorder.FrameRecorder(
canvas,
path=None,
fps=None,
render_scale=100,
frames_dir=None,
overwrite=True,
)Collect manually rendered frames into an animation.
Where animation renders an animation by playing back the Blender timeline, a recorder gives the loop to you: change anything about the scene between frames - the timeline, the camera, styles, colors - and call :meth:render to capture the scene as it stands as the next frame. :meth:finalize assembles the captured frames into an MP4 or GIF.
Created via record rather than directly. Frames are rendered as PNGs into a temporary directory that lives (and is cleaned up) with the recorder, or into frames_dir when one is given, where they stay after the recorder is gone. With overwrite=False, frames already in frames_dir are reused rather than re-rendered, resuming an interrupted recording.
A recorder is also a context manager: when a path was given to record, leaving the with block without an exception finalizes to that path automatically.
Examples
Explicit finalize, which returns the animation for notebook display::
movie = canvas.record(fps=24)
for i in range(120):
traj.frame = i
canvas.look_at(traj)
movie.render()
movie.finalize("wobble.mp4")As a context manager, finalizing on exit::
with canvas.record("wobble.mp4", fps=24) as movie:
for i in range(120):
traj.frame = i
movie.render()See Also
molecularnodes.Canvas.record : Create a recorder bound to a canvas. molecularnodes.Canvas.animation : Render an animation from the timeline.
Attributes
| Name | Description |
|---|---|
| frames | Get the frames captured so far. |
Methods
| Name | Description |
|---|---|
| finalize | Assemble the captured frames into an animation. |
| render | Render the scene as it stands and store it as the next frame. |
finalize
scene.recorder.FrameRecorder.finalize(path=None, fps=None, format=None)Assemble the captured frames into an animation.
The recorder is left intact: more frames can be rendered and finalize called again, e.g. to write both an MP4 and a GIF of the same recording.
Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| path | str | Path | None | File path to write the animation to, defaulting to the one given to record. The animation is returned for display regardless of whether a path is given. |
None |
| fps | float | Frame rate of the animation. Defaults to the rate given to record, or failing that the scene’s fps. |
None |
| format | str | Output format, either "MP4" or "GIF" (case-insensitive). When not specified, inferred from the suffix of path, defaulting to MP4. GIF output requires the pillow package. |
None |
Returns
| Name | Type | Description |
|---|---|---|
IPython.display.Video | IPython.display.Image | None |
The assembled animation (a Video for MP4, an Image for GIF), which displays automatically as the result of a notebook cell. None if IPython is not installed. |
Raises
| Name | Type | Description |
|---|---|---|
| RuntimeError | If no frames have been rendered yet. |
render
scene.recorder.FrameRecorder.render(render_scale=None)Render the scene as it stands and store it as the next frame.
Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| render_scale | int | Scale of the rendered frame with respect to the resolution, overriding the recorder’s default for this frame. | None |
Returns
| Name | Type | Description |
|---|---|---|
| pathlib.Path | Path of the rendered PNG frame. |
Raises
| Name | Type | Description |
|---|---|---|
| ValueError | If the frame’s pixel size differs from the frames already captured - all frames of an animation must share one resolution. |
Notes
With overwrite=False (and a frames_dir), a frame whose numbered file already exists is reused instead of re-rendered, so re-running the same loop after a crash only renders the frames that are missing.