""" Stereo 3D viewer ================ Two side-by-side 3D viewers with the same layers and synchronized cameras. A small horizontal eye separation is applied so the pair can be viewed stereoscopically (parallel / wall-eyed fusion). Interact with either eye view or the main viewer: angles, zoom, and perspective stay locked; only the look-at center is offset left/right. Use the eye-separation spinbox to tune parallax for your data and screen size. Cross-eyed viewing: use a negative separation. .. tags:: gui, visualization-nD """ import numpy as np from qtpy.QtCore import Qt from qtpy.QtWidgets import ( QApplication, QDoubleSpinBox, QHBoxLayout, QLabel, QMainWindow, QVBoxLayout, QWidget, ) import napari from napari.components.camera import Camera from napari.components.viewer_model import ViewerModel from napari.layers import Layer from napari.qt import QtViewer, get_stylesheet from napari.settings import get_settings class StereoViewerWindow(QMainWindow): def closeEvent(self, event) -> None: # Avoid macOS black-space quirk when closing while fullscreen # (borrowed idea from napari's main window closeEvent). if self.isFullScreen(): self.showNormal() super().closeEvent(event) def copy_layer(layer: Layer) -> Layer: return Layer.create(*layer.as_layer_data_tuple()) class StereoViewerWidget(QWidget): """Side-by-side 3D viewers with a stereo camera offset.""" def __init__(self, viewer: napari.Viewer) -> None: super().__init__() self.viewer = viewer self.viewer_left = ViewerModel(title='left eye') self.viewer_right = ViewerModel(title='right eye') self._block = False self._eye_separation = 20.0 # Reused only to derive view/up directions from Euler angles. self._direction_camera = Camera() # Create viewers first, then add layers self.qt_left = QtViewer(self.viewer_left) self.qt_right = QtViewer(self.viewer_right) for layer in viewer.layers: self.viewer_left.layers.append(copy_layer(layer)) self.viewer_right.layers.append(copy_layer(layer)) for model in self._all_models(): model.dims.ndisplay = 3 # eye separation control controls = QHBoxLayout() controls.addWidget(QLabel('Eye separation')) self.separation_spin = QDoubleSpinBox() self.separation_spin.setRange(-500.0, 500.0) self.separation_spin.setSingleStep(1.0) self.separation_spin.setDecimals(1) self.separation_spin.setValue(self._eye_separation) self.separation_spin.valueChanged.connect(self._on_separation_changed) controls.addWidget(self.separation_spin) controls.addStretch(1) # left and right eye viewers eye_layout = QHBoxLayout() eye_layout.addWidget(self.qt_left) eye_layout.addWidget(self.qt_right) # main layout layout = QVBoxLayout() layout.setContentsMargins(0, 0, 0, 0) layout.addLayout(controls) layout.addLayout(eye_layout) self.setLayout(layout) for model in self._all_models(): model.camera.events.angles.connect(self._camera_update) model.camera.events.center.connect(self._camera_update) model.camera.events.zoom.connect(self._camera_update) model.camera.events.perspective.connect(self._camera_update) self.viewer.events.reset_view.connect(self._reset_view) # Mild perspective helps stereo depth cues. self.viewer.camera.perspective = 30 def _all_models(self) -> tuple[ViewerModel, ViewerModel, ViewerModel]: return (self.viewer, self.viewer_left, self.viewer_right) def _camera_right_vector( self, angles: tuple[float, float, float] ) -> np.ndarray: """Unit vector pointing right on the canvas for the given Euler angles.""" self._direction_camera.angles = angles right = np.cross( self._direction_camera.up_direction, self._direction_camera.view_direction, ) norm = np.linalg.norm(right) if norm < 1e-8: return np.array([0.0, 0.0, 1.0]) return right / norm def _on_separation_changed(self, value: float) -> None: # when the eye separation is changed, re-calculate and apply camera state to all viewers self._eye_separation = value cam = self.viewer.camera self._apply_stereo_from( cam.angles, cam.center, cam.zoom, cam.perspective ) def _reset_view(self) -> None: # Main viewer already reset; push its camera through stereo sync. cam = self.viewer.camera self._apply_stereo_from( cam.angles, cam.center, cam.zoom, cam.perspective ) def _base_center_from( self, model: ViewerModel, angles: tuple[float, float, float], center: tuple[float, float, float] | tuple[float, float], ) -> np.ndarray: """Shared (cyclopean) look-at center implied by an eye camera center.""" right_direction = self._camera_right_vector(angles) half = self._eye_separation / 2.0 center_arr = np.asarray(center, dtype=float) if model is self.viewer_left: return center_arr + half * right_direction if model is self.viewer_right: return center_arr - half * right_direction return center_arr def _apply_stereo_from( self, angles: tuple[float, float, float], center: tuple[float, float, float] | tuple[float, float] | np.ndarray, zoom: float, perspective: float, ) -> None: """Apply shared camera state with left/right look-at offsets.""" right_direction = self._camera_right_vector(angles) half = self._eye_separation / 2.0 base = np.asarray(center, dtype=float) prev = self._block self._block = True try: for model, sign in ( (self.viewer, 0.0), (self.viewer_left, -1.0), (self.viewer_right, 1.0), ): model.camera.angles = angles model.camera.zoom = zoom model.camera.perspective = perspective model.camera.center = tuple( base + sign * half * right_direction ) finally: self._block = prev def _camera_update(self, event) -> None: if self._block: return source_cam = event.source model = next(m for m in self._all_models() if m.camera is source_cam) # shared look-at without this eye's stereo offset base = self._base_center_from( model, source_cam.angles, source_cam.center ) # apply the stereo effect to the viewer self._apply_stereo_from( source_cam.angles, base, source_cam.zoom, source_cam.perspective, ) if __name__ == '__main__': # Needed so additional OpenGL canvases can share contexts with the main viewer. QApplication.setAttribute(Qt.ApplicationAttribute.AA_ShareOpenGLContexts) viewer = napari.Viewer(ndisplay=3) viewer.open_sample('napari', 'cells3d') viewer.camera.angles = (-20, 20, -20) window = StereoViewerWindow() window.setStyleSheet(get_stylesheet(get_settings().appearance.theme)) window.setWindowTitle('Stereo 3D') window.setCentralWidget(StereoViewerWidget(viewer)) window.resize(1000, 500) window.show() napari.run()