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Render¤

Offline rendering to textures.

vape4d.render ¤

render ¤
render(
    volume: ndarray,
    cmap: Optional[Colormap] = None,
    time: Optional[Union[float, List[float]]] = 0.0,
    width: int = 1024,
    height: int = 1024,
    background: Tuple[float, float, float, float] = (
        0,
        0,
        0,
        1,
    ),
    vmin: Optional[float] = None,
    vmax: Optional[float] = None,
    distance_scale: float = 1.0,
    spatial_interpolation: str = "linear",
    temporal_interpolation: str = "linear",
    camera_angle: Optional[Tuple[float, float]] = None,
) -> np.ndarray

renders a single or multiple images of a volume

Parameters:

Name Type Description Default
volume ndarray

volume data of shape [N, D, H, W]

 required
cmap Colormap

colormap to use for rendering. Defaults to matplotlib's default colormap.

 None
time Union[float, list[float]]

if a single value is given, a single image is rendered at that time. If a list of values is given, a video is rendered with the given times.

 0.0
width int

image width. Defaults to 1024.

 1024
height int

image height. Defaults to 1024.

 1024
background tuple[float, float, float, float]

background color. Defaults to (0, 0, 0, 1).

 (0, 0, 0, 1)
vmin Optional[float]

minimum value for colormap. defaults to minimum value in volume.

 None
vmax Optional[float]

maximum value for colormap. defaults to maximum value in volume.

 None
distance_scale float

distance scale for rendering. A larger value makes everything more opaque. Defaults to 1.0.

 1.0
spatial_interpolation str

interpolation in space. Linear or Nearest. Defaults to "linear".

 'linear'
temporal_interpolation str

interpolation in time. Linear or Nearest. Defaults to "linear".

 'linear'
camera_angle Optional[Tuple[float, float]]

camera angle for rendering in spherical coordinates (polar,azimuthal angle ). Defaults to None.

 None

Returns:

Type Description
ndarray

np.ndarray: [T, H, W, 4] if time is a list, [H, W, 4] if time is a single value
Source code in vape4d/render.py 
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def render(
    volume: np.ndarray,
    cmap: Optional[Colormap] = None,
    time: Optional[Union[float, List[float]]] = 0.0,
    width: int = 1024,
    height: int = 1024,
    background: Tuple[float, float, float, float] = (0, 0, 0, 1),
    vmin: Optional[float] = None,
    vmax: Optional[float] = None,
    distance_scale: float = 1.0,
    spatial_interpolation: str = "linear",
    temporal_interpolation: str = "linear",
    camera_angle: Optional[Tuple[float, float]] = None,
) -> np.ndarray:
    """renders a single or multiple images of a volume

    Args:
        volume (np.ndarray): volume data of shape [N, D, H, W]
        cmap (Colormap): colormap to use for rendering. Defaults to matplotlib's default colormap.
        time (Union[float, list[float]]): if a single value is given, a single image is rendered at that time. If a list of values is given, a video is rendered with the given times.
        width (int, optional): image width. Defaults to 1024.
        height (int, optional): image height. Defaults to 1024.
        background (tuple[float, float, float, float], optional): background color. Defaults to (0, 0, 0, 1).
        vmin (Optional[float], optional): minimum value for colormap. defaults to minimum value in volume.
        vmax (Optional[float], optional): maximum value for colormap. defaults to maximum value in volume.
        distance_scale (float, optional): distance scale for rendering. A larger value makes everything more opaque. Defaults to 1.0.
        spatial_interpolation (str, optional): interpolation in space. Linear or Nearest. Defaults to "linear".
        temporal_interpolation (str, optional): interpolation in time. Linear or Nearest. Defaults to "linear".
        camera_angle (Optional[Tuple[float, float]], optional): camera angle for rendering in spherical coordinates (polar,azimuthal angle ). Defaults to None.

    Returns:
        np.ndarray: [T, H, W, 4] if time is a list, [H, W, 4] if time is a single value
    """

    if cmap is None:
        cmap = plt.get_cmap()

    if volume.ndim == 5:
        # check if we have a single channel
        if volume.shape[1] != 1:
            raise ValueError("only one channel supported")
    elif volume.ndim == 4:
        pass
    elif volume.ndim == 3:
        # add one channel
        volume = volume[:, None]
    else:
        raise ValueError(
            "volume must have shape [T,1, D, H, W], [T, D, H, W] or [D,H,W] "
        )

    colormap_data = cmap(np.linspace(0, 1, 256)).astype(np.float32)

    if isinstance(time, np.ndarray):
        time = time.tolist()

    if not isinstance(time, list):
        time = [time]

    frames = vape4d.render_video(
        np.ascontiguousarray(volume).astype(np.float16),
        colormap_data,
        width,
        height,
        time,
        background,
        distance_scale,
        vmin,
        vmax,
        spatial_interpolation,
        temporal_interpolation,
        camera_angle,
    )
    if len(time) == 1:
        return frames[0]
    return frames