.. Comment: this file is automatically generated by `update_example_docs.py`.
   It should not be modified manually.

Lights
==========================================


Visualize a mesh under different lighting conditions. To get the demo data, see ``./assets/download_dragon_mesh.sh``.



.. code-block:: python
        :linenos:


        import time
        from pathlib import Path

        import numpy as np
        import trimesh

        import viser
        import viser.transforms as tf


        def main() -> None:
            # Load mesh.
            mesh = trimesh.load_mesh(str(Path(__file__).parent / "assets/dragon.obj"))
            assert isinstance(mesh, trimesh.Trimesh)
            mesh.apply_scale(0.05)
            vertices = mesh.vertices
            faces = mesh.faces
            print(f"Loaded mesh with {vertices.shape} vertices, {faces.shape} faces")

            # Start Viser server with mesh.
            server = viser.ViserServer()

            server.scene.add_mesh_simple(
                name="/simple",
                vertices=vertices,
                faces=faces,
                wxyz=tf.SO3.from_x_radians(np.pi / 2).wxyz,
                position=(0.0, 0.0, 0.0),
            )
            server.scene.add_mesh_trimesh(
                name="/trimesh",
                mesh=mesh,
                wxyz=tf.SO3.from_x_radians(np.pi / 2).wxyz,
                position=(0.0, 5.0, 0.0),
            )

            # adding controls to custom lights in the scene
            server.scene.add_transform_controls("/control0", position=(0.0, 10.0, 5.0))
            server.scene.add_label("/control0/label", "Directional")
            server.scene.add_transform_controls("/control1", position=(0.0, -5.0, 5.0))
            server.scene.add_label("/control1/label", "Point")

            directional_light = server.scene.add_light_directional(
                name="/control0/directional_light",
                color=(186, 219, 173),
            )
            point_light = server.scene.add_light_point(
                name="/control1/point_light",
                color=(192, 255, 238),
                intensity=30.0,
            )

            # Create default light toggle.
            gui_default_lights = server.gui.add_checkbox("Default lights", initial_value=True)
            gui_default_lights.on_update(
                lambda _: server.scene.enable_default_lights(gui_default_lights.value)
            )

            # Create light control inputs.
            with server.gui.add_folder("Directional light"):
                gui_directional_color = server.gui.add_rgb(
                    "Color", initial_value=directional_light.color
                )
                gui_directional_intensity = server.gui.add_slider(
                    "Intensity",
                    min=0.0,
                    max=20.0,
                    step=0.01,
                    initial_value=directional_light.intensity,
                )

                @gui_directional_color.on_update
                def _(_) -> None:
                    directional_light.color = gui_directional_color.value

                @gui_directional_intensity.on_update
                def _(_) -> None:
                    directional_light.intensity = gui_directional_intensity.value

            with server.gui.add_folder("Point light"):
                gui_point_color = server.gui.add_rgb("Color", initial_value=point_light.color)
                gui_point_intensity = server.gui.add_slider(
                    "Intensity",
                    min=0.0,
                    max=200.0,
                    step=0.01,
                    initial_value=point_light.intensity,
                )

                @gui_point_color.on_update
                def _(_) -> None:
                    point_light.color = gui_point_color.value

                @gui_point_intensity.on_update
                def _(_) -> None:
                    point_light.intensity = gui_point_intensity.value

            # Create GUI elements for controlling environment map.
            with server.gui.add_folder("Environment map"):
                gui_env_preset = server.gui.add_dropdown(
                    "Preset",
                    (
                        "None",
                        "apartment",
                        "city",
                        "dawn",
                        "forest",
                        "lobby",
                        "night",
                        "park",
                        "studio",
                        "sunset",
                        "warehouse",
                    ),
                    initial_value="city",
                )
                gui_background = server.gui.add_checkbox("Background", False)
                gui_bg_blurriness = server.gui.add_slider(
                    "Bg Blurriness",
                    min=0.0,
                    max=1.0,
                    step=0.01,
                    initial_value=0.0,
                )
                gui_bg_intensity = server.gui.add_slider(
                    "Bg Intensity",
                    min=0.0,
                    max=1.0,
                    step=0.01,
                    initial_value=1.0,
                )
                gui_env_intensity = server.gui.add_slider(
                    "Env Intensity",
                    min=0.0,
                    max=1.0,
                    step=0.01,
                    initial_value=0.1,
                )

            def update_environment_map(_) -> None:
                server.scene.set_environment_map(
                    gui_env_preset.value if gui_env_preset.value != "None" else None,
                    background=gui_background.value,
                    background_blurriness=gui_bg_blurriness.value,
                    background_intensity=gui_bg_intensity.value,
                    environment_intensity=gui_env_intensity.value,
                )

            update_environment_map(None)
            gui_env_preset.on_update(update_environment_map)
            gui_background.on_update(update_environment_map)
            gui_bg_blurriness.on_update(update_environment_map)
            gui_bg_intensity.on_update(update_environment_map)
            gui_env_intensity.on_update(update_environment_map)

            while True:
                time.sleep(10.0)


        if __name__ == "__main__":
            main()