Blending#

import cmap
import numpy as np

import scenex as snx
import scenex.model
from scenex.app.events import Event, MousePressEvent
from scenex.model._transform import Transform
from scenex.utils import projections

try:
    from imageio.v2 import volread

    url = "https://gitlab.com/scikit-image/data/-/raw/2cdc5ce89b334d28f06a58c9f0ca21aa6992a5ba/cells3d.tif"
    data = np.asarray(volread(url)).astype(np.uint16)[:, :, :, :]
except ImportError:
    data = np.random.randint(0, 2, (3, 2, 3, 3)).astype(np.uint16)

data1 = data[:, 0, :, :]
volume1 = snx.Volume(
    data=data1,
    cmap=cmap.Colormap("green"),
    blending=scenex.model.BlendMode.ADDITIVE,
    clims=(data1.min(), data1.max()),
    opacity=0.7,
    order=1,
    name="Cell membranes",
    interactive=True,
)
data2 = data[:, 1, :, :]
volume2 = snx.Volume(
    data=data2,
    blending=scenex.model.BlendMode.ADDITIVE,
    cmap=cmap.Colormap("magenta"),
    clims=(data2.min(), data2.max()),
    opacity=0.7,
    order=2,
    name="Cell nuclei",
    interactive=True,
    transform=Transform().translated((0, 0, 30)),
)

view = snx.View(
    scene=snx.Scene(
        children=[volume1, volume2],
        interactive=True,
    ),
    camera=snx.Camera(interactive=True),
)

blend_modes = list(scenex.model.BlendMode)


def change_blend_mode(event: Event) -> bool:
    """Change the blend mode of a volume when it is clicked."""
    if not isinstance(event, (MousePressEvent)):
        return False
    if not (ray := view.to_ray(event.pos)):
        return False
    if not ray.intersections(volume1):
        return False
    idx = blend_modes.index(volume1.blending)
    next_idx = (idx + 1) % len(blend_modes)

    print(f"Changing blend mode to {blend_modes[next_idx]}")

    volume1.blending = blend_modes[next_idx]
    volume2.blending = blend_modes[next_idx]
    return False


view.set_event_filter(change_blend_mode)

snx.show(view)

# Orbit around the center of the volume
orbit_center = np.mean(np.asarray(view.scene.bounding_box), axis=0)

# Place the camera along the x axis, looking at the orbit center
view.camera.transform = Transform().translated(orbit_center).translated((300, 0, 0))
view.camera.look_at(orbit_center, up=(0, 0, 1))
# Perspective projection for 3D
view.camera.projection = projections.perspective(
    fov=70,
    near=1,
    far=1_000_000,  # Just need something big
)
view.camera.controller = snx.Orbit(center=orbit_center)

snx.run()