big

scenes/maps/cloud_sun_sync.gd

@@ -0,0 +1,43 @@
+extends Node
+class_name CloudSunSync
+
+## Keeps the fullscreen sky composite tied to the real DirectionalLight3D.
+##
+## The Environment sky shader receives LIGHT0_DIRECTION automatically, but the
+## ink pass has to repaint background pixels after the screen copy. This bridge
+## gives that second shader the same moving direction and color every frame.
+
+var _sun: DirectionalLight3D
+var _ink_material: ShaderMaterial
+var _palette_sun_color := Color.WHITE
+
+
+func configure(sun: DirectionalLight3D, ink_material: ShaderMaterial) -> void:
+	_sun = sun
+	_ink_material = ink_material
+	var authored = ink_material.get_shader_parameter("sky_sun_color")
+	if authored is Color:
+		_palette_sun_color = authored
+	_sync()
+
+
+func _process(_delta: float) -> void:
+	_sync()
+
+
+func _sync() -> void:
+	if not is_instance_valid(_sun) or not is_instance_valid(_ink_material):
+		set_process(false)
+		return
+
+	# DirectionalLight3D shines down its local -Z axis, so +Z points back
+	# toward the apparent sun—the direction a sky pixel uses for illumination.
+	var toward_sun := _sun.global_transform.basis.z.normalized()
+	_ink_material.set_shader_parameter("sky_sun_direction", toward_sun)
+
+	# Preserve the authored day/sunset palette while allowing a dynamically
+	# recolored sun to tint the cloud's lit face.
+	var live_color := _palette_sun_color.lerp(_sun.light_color, 0.35)
+	var energy_scale: float = clampf(_sun.light_energy / 1.4, 0.75, 1.25)
+	_ink_material.set_shader_parameter(
+			"sky_sun_color", live_color * energy_scale)