GUI callbacks#

Asynchronous usage of GUI elements: we can attach callbacks that are called as soon as we get updates.

  1import time
  2
  3import numpy as onp
  4import viser
  5from typing_extensions import assert_never
  6
  7
  8def main() -> None:
  9    server = viser.ViserServer()
 10
 11    gui_reset_scene = server.gui.add_button("Reset Scene")
 12
 13    gui_plane = server.gui.add_dropdown(
 14        "Grid plane", ("xz", "xy", "yx", "yz", "zx", "zy")
 15    )
 16
 17    def update_plane() -> None:
 18        server.scene.add_grid(
 19            "/grid",
 20            width=10.0,
 21            height=20.0,
 22            width_segments=10,
 23            height_segments=20,
 24            plane=gui_plane.value,
 25        )
 26
 27    gui_plane.on_update(lambda _: update_plane())
 28
 29    with server.gui.add_folder("Control"):
 30        gui_show_frame = server.gui.add_checkbox("Show Frame", initial_value=True)
 31        gui_show_everything = server.gui.add_checkbox(
 32            "Show Everything", initial_value=True
 33        )
 34        gui_axis = server.gui.add_dropdown("Axis", ("x", "y", "z"))
 35        gui_include_z = server.gui.add_checkbox("Z in dropdown", initial_value=True)
 36
 37        @gui_include_z.on_update
 38        def _(_) -> None:
 39            gui_axis.options = ("x", "y", "z") if gui_include_z.value else ("x", "y")
 40
 41        with server.gui.add_folder("Sliders"):
 42            gui_location = server.gui.add_slider(
 43                "Location", min=-5.0, max=5.0, step=0.05, initial_value=0.0
 44            )
 45            gui_num_points = server.gui.add_slider(
 46                "# Points", min=1000, max=200_000, step=1000, initial_value=10_000
 47            )
 48
 49    def draw_frame() -> None:
 50        axis = gui_axis.value
 51        if axis == "x":
 52            pos = (gui_location.value, 0.0, 0.0)
 53        elif axis == "y":
 54            pos = (0.0, gui_location.value, 0.0)
 55        elif axis == "z":
 56            pos = (0.0, 0.0, gui_location.value)
 57        else:
 58            assert_never(axis)
 59
 60        server.scene.add_frame(
 61            "/frame",
 62            wxyz=(1.0, 0.0, 0.0, 0.0),
 63            position=pos,
 64            show_axes=gui_show_frame.value,
 65            axes_length=5.0,
 66        )
 67
 68    def draw_points() -> None:
 69        num_points = gui_num_points.value
 70        server.scene.add_point_cloud(
 71            "/frame/point_cloud",
 72            points=onp.random.normal(size=(num_points, 3)),
 73            colors=onp.random.randint(0, 256, size=(num_points, 3)),
 74        )
 75
 76    # We can (optionally) also attach callbacks!
 77    # Here, we update the point clouds + frames whenever any of the GUI items are updated.
 78    gui_show_frame.on_update(lambda _: draw_frame())
 79    gui_show_everything.on_update(
 80        lambda _: server.scene.set_global_visibility(gui_show_everything.value)
 81    )
 82    gui_axis.on_update(lambda _: draw_frame())
 83    gui_location.on_update(lambda _: draw_frame())
 84    gui_num_points.on_update(lambda _: draw_points())
 85
 86    @gui_reset_scene.on_click
 87    def _(_) -> None:
 88        """Reset the scene when the reset button is clicked."""
 89        gui_show_frame.value = True
 90        gui_location.value = 0.0
 91        gui_axis.value = "x"
 92        gui_num_points.value = 10_000
 93
 94        draw_frame()
 95        draw_points()
 96
 97    # Finally, let's add the initial frame + point cloud and just loop infinitely. :)
 98    update_plane()
 99    draw_frame()
100    draw_points()
101    while True:
102        time.sleep(1.0)
103
104
105if __name__ == "__main__":
106    main()