How to use the pyrender.DirectionalLight function in pyrender

boxv_trimesh.visual.vertex_colors = boxv_vertex_colors
    boxv_mesh = Mesh.from_trimesh(boxv_trimesh, smooth=False)
    boxf_trimesh = trimesh.creation.box(extents=0.1 * np.ones(3))
    boxf_face_colors = np.random.uniform(size=boxf_trimesh.faces.shape)
    boxf_trimesh.visual.face_colors = boxf_face_colors
    # Instanced
    poses = np.tile(np.eye(4), (2,1,1))
    poses[0,:3,3] = np.array([-0.1, -0.10, 0.05])
    poses[1,:3,3] = np.array([-0.15, -0.10, 0.05])
    boxf_mesh = Mesh.from_trimesh(boxf_trimesh, poses=poses, smooth=False)

    points = trimesh.creation.icosphere(radius=0.05).vertices
    point_colors = np.random.uniform(size=points.shape)
    points_mesh = Mesh.from_points(points, colors=point_colors)

    direc_l = DirectionalLight(color=np.ones(3), intensity=1.0)
    spot_l = SpotLight(color=np.ones(3), intensity=10.0,
                       innerConeAngle=np.pi / 16, outerConeAngle=np.pi / 6)

    cam = PerspectiveCamera(yfov=(np.pi / 3.0))
    cam_pose = np.array([
        [0.0, -np.sqrt(2) / 2, np.sqrt(2) / 2, 0.5],
        [1.0, 0.0, 0.0, 0.0],
        [0.0, np.sqrt(2) / 2, np.sqrt(2) / 2, 0.4],
        [0.0, 0.0, 0.0, 1.0]
    ])

    scene = Scene(ambient_light=np.array([0.02, 0.02, 0.02]))

    fuze_node = Node(mesh=fuze_mesh, translation=np.array([
        0.1, 0.15, -np.min(fuze_trimesh.vertices[:,2])
    ]))

mesh = trimesh.creation.box(extents=cube_size * np.ones(3))
        mesh = Mesh.from_trimesh(mesh, smooth=False)
        node = Node(
            mesh=mesh,
            translation=np.array(([
                position[0] - barycenter[0],
                position[1] - barycenter[1],
                position[2] - barycenter[2],
            ])))
        scene.add_node(node)
        cube_nodes.append(node)

    update_cube_color_and_position(cube_nodes, color_candidates)

    # Place a light
    light = DirectionalLight(color=np.ones(3), intensity=15.0)
    quaternion_yaw = pyrender.quaternion.from_yaw(math.pi / 4)
    quaternion_pitch = pyrender.quaternion.from_pitch(-math.pi / 5)
    quaternion = pyrender.quaternion.multiply(quaternion_pitch, quaternion_yaw)
    quaternion = quaternion / np.linalg.norm(quaternion)
    node = Node(
        light=light, rotation=quaternion, translation=np.array([1, 1, 1]))
    scene.add_node(node)

    return scene, cube_nodes

mesh = Mesh.from_trimesh(wall_trimesh)
    node = Node(
        mesh=mesh,
        rotation=pyrender.quaternion.from_yaw(math.pi / 2),
        translation=np.array([-3.5, 1.15, 0]))
    set_random_texture(node, texture_path)
    scene.add_node(node)

    # light = PointLight(color=np.ones(3), intensity=200.0)
    # node = Node(
    #     light=light,
    #     translation=np.array([0, 5, 5]))
    # scene.add_node(node)

    light = DirectionalLight(color=np.ones(3), intensity=10)
    position = np.array([0, 1, 1])
    position = position / np.linalg.norm(position)
    yaw, pitch = compute_yaw_and_pitch(position)
    node = Node(
        light=light,
        rotation=genearte_camera_quaternion(yaw, pitch),
        translation=np.array([0, 1, 1]))
    scene.add_node(node)

    # Place objects
    directions = [-1.0, 0.0, 1.0]
    available_positions = []
    for z in directions:
        for x in directions:
            available_positions.append((x, z))
    available_positions = np.array(available_positions)

node = Node(
        mesh=mesh,
        rotation=pyrender.quaternion.from_yaw(-math.pi / 2),
        translation=np.array([3.5, 1.15, 0]))
    set_random_texture(node, texture_path)
    scene.add_node(node)

    mesh = Mesh.from_trimesh(wall_trimesh, smooth=False)
    node = Node(
        mesh=mesh,
        rotation=pyrender.quaternion.from_yaw(math.pi / 2),
        translation=np.array([-3.5, 1.15, 0]))
    set_random_texture(node, texture_path)
    scene.add_node(node)

    light = DirectionalLight(color=np.ones(3), intensity=10)
    if fix_light_position == True:
        translation = np.array([1, 1, 1])
    else:
        xz = np.random.uniform(-1, 1, size=2)
        translation = np.array([xz[0], 1, xz[1]])
    yaw, pitch = compute_yaw_and_pitch(translation)
    node = Node(
        light=light,
        rotation=genearte_camera_quaternion(yaw, pitch),
        translation=translation)
    scene.add_node(node)

    return scene

mesh = Mesh.from_trimesh(wall_trimesh)
    node = Node(
        mesh=mesh,
        rotation=pyrender.quaternion.from_yaw(math.pi / 2),
        translation=np.array([-3.5, 1.15, 0]))
    set_random_texture(node, texture_path)
    scene.add_node(node)

    # light = PointLight(color=np.ones(3), intensity=200.0)
    # node = Node(
    #     light=light,
    #     translation=np.array([0, 5, 5]))
    # scene.add_node(node)

    light = DirectionalLight(color=np.ones(3), intensity=10)
    position = np.array([0, 1, 1])
    position = position / np.linalg.norm(position)
    yaw, pitch = compute_yaw_and_pitch(position)
    node = Node(
        light=light,
        rotation=genearte_camera_quaternion(yaw, pitch),
        translation=np.array([0, 1, 1]))
    scene.add_node(node)

    # Place objects
    directions = [-1.0, 0.0, 1.0]
    available_positions = []
    for z in directions:
        for x in directions:
            available_positions.append((x, z))
    available_positions = np.array(available_positions)

boxf_face_colors = np.random.uniform(size=boxf_trimesh.faces.shape)
boxf_trimesh.visual.face_colors = boxf_face_colors
boxf_mesh = Mesh.from_trimesh(boxf_trimesh, smooth=False)

#------------------------------------------------------------------------------
# Creating meshes from point clouds
#------------------------------------------------------------------------------
points = trimesh.creation.icosphere(radius=0.05).vertices
point_colors = np.random.uniform(size=points.shape)
points_mesh = Mesh.from_points(points, colors=point_colors)

#==============================================================================
# Light creation
#==============================================================================

direc_l = DirectionalLight(color=np.ones(3), intensity=1.0)
spot_l = SpotLight(color=np.ones(3), intensity=10.0,
                   innerConeAngle=np.pi/16, outerConeAngle=np.pi/6)
point_l = PointLight(color=np.ones(3), intensity=10.0)

#==============================================================================
# Camera creation
#==============================================================================

cam = PerspectiveCamera(yfov=(np.pi / 3.0))
cam_pose = np.array([
    [0.0,  -np.sqrt(2)/2, np.sqrt(2)/2, 0.5],
    [1.0, 0.0,           0.0,           0.0],
    [0.0,  np.sqrt(2)/2,  np.sqrt(2)/2, 0.4],
    [0.0,  0.0,           0.0,          1.0]
])

mesh = trimesh.creation.box(extents=cube_size * np.ones(3))
        mesh = Mesh.from_trimesh(mesh, smooth=False)
        node = Node(
            mesh=mesh,
            translation=np.array(([
                position[0] - center_of_gravity[0],
                position[1] - center_of_gravity[1],
                position[2] - center_of_gravity[2],
            ])))
        scene.add_node(node)
        cube_nodes.append(node)

    update_cube_color_and_position(cube_nodes, color_candidates)

    # Place a light
    light = DirectionalLight(color=np.ones(3), intensity=15.0)
    quaternion_yaw = pyrender.quaternion.from_yaw(math.pi / 4)
    quaternion_pitch = pyrender.quaternion.from_pitch(-math.pi / 5)
    quaternion = pyrender.quaternion.multiply(quaternion_pitch, quaternion_yaw)
    quaternion = quaternion / np.linalg.norm(quaternion)
    node = Node(
        light=light, rotation=quaternion, translation=np.array([1, 1, 1]))
    scene.add_node(node)

    return scene, cube_nodes