Function add_sun

tools/cycles_reference/render.py:281–307

Add a Sun light aimed along the given direction (in Bloom Y-up). In Bloom, `setDirectionalLight` direction is the vector *toward* the light source. Blender's Sun shines along the light's local -Z axis. We orient the Sun so its -Z points in the opposite of dir_bloom (i.e. the directi

(name, dir_bloom, color, strength)

def add_sun(name, dir_bloom, color, strength):
    """Add a Sun light aimed along the given direction (in Bloom Y-up).

    In Bloom, `setDirectionalLight` direction is the vector *toward* the
    light source. Blender's Sun shines along the light's local -Z axis.
    We orient the Sun so its -Z points in the opposite of dir_bloom
    (i.e. the direction the light travels).
    """
    light_data = bpy.data.lights.new(name=name, type='SUN')
    light_data.color = color
    light_data.energy = strength
    light_data.angle = math.radians(0.53)  # ~solar disc size; soft shadow

    light_obj = bpy.data.objects.new(name=name, object_data=light_data)
    bpy.context.collection.objects.link(light_obj)

    # The direction the light *travels* is -dir_bloom
    travel_bloom = (-dir_bloom[0], -dir_bloom[1], -dir_bloom[2])
    travel_b = Vector(bloom_to_blender(travel_bloom)).normalized()

    # Orient so local -Z aligns with travel_b.
    # Track_quat returns a rotation mapping the chosen axis onto the vector.
    # We want -Z to look along travel_b, which is equivalent to asking the
    # quat that maps '-Z' onto travel_b.
    rot = travel_b.to_track_quat('-Z', 'Y')
    light_obj.rotation_mode = 'QUATERNION'
    light_obj.rotation_quaternion = rot


def setup_camera():