From 3f095ca2c275a4dcd50890a7acfed60ee1a84706 Mon Sep 17 00:00:00 2001
From: matheusmdx <matheus_henriquemdx@hotmail.com>
Date: Thu, 24 Oct 2024 21:39:55 -0300
Subject: [PATCH] Print a warning when using sky with transparent background
 active

---
 scene/3d/world_environment.cpp  | 37 +++++++++++++++++++++++++++++----
 scene/3d/world_environment.h    |  2 ++
 scene/resources/environment.cpp |  4 ++++
 3 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/scene/3d/world_environment.cpp b/scene/3d/world_environment.cpp
index 82b7c160a4cc..3c3d038333d2 100644
--- a/scene/3d/world_environment.cpp
+++ b/scene/3d/world_environment.cpp
@@ -30,6 +30,7 @@
 
 #include "world_environment.h"
 
+#include "core/config/project_settings.h"
 #include "scene/3d/node_3d.h"
 #include "scene/main/window.h"
 
@@ -37,6 +38,8 @@ void WorldEnvironment::_notification(int p_what) {
 	switch (p_what) {
 		case Node3D::NOTIFICATION_ENTER_WORLD:
 		case Node3D::NOTIFICATION_ENTER_TREE: {
+			_check_sky_warning();
+
 			if (environment.is_valid()) {
 				add_to_group("_world_environment_" + itos(get_viewport()->find_world_3d()->get_scenario().get_id()));
 				_update_current_environment();
@@ -110,14 +113,20 @@ void WorldEnvironment::set_environment(const Ref<Environment> &p_environment) {
 	if (environment == p_environment) {
 		return;
 	}
-	if (is_inside_tree() && environment.is_valid()) {
-		remove_from_group("_world_environment_" + itos(get_viewport()->find_world_3d()->get_scenario().get_id()));
+	if (environment.is_valid()) {
+		environment->disconnect(StringName("sky_changed"), callable_mp(this, &WorldEnvironment::_check_sky_warning));
+		if (is_inside_tree()) {
+			remove_from_group("_world_environment_" + itos(get_viewport()->find_world_3d()->get_scenario().get_id()));
+		}
 	}
 
 	environment = p_environment;
 
-	if (is_inside_tree() && environment.is_valid()) {
-		add_to_group("_world_environment_" + itos(get_viewport()->find_world_3d()->get_scenario().get_id()));
+	if (environment.is_valid()) {
+		environment->connect(StringName("sky_changed"), callable_mp(this, &WorldEnvironment::_check_sky_warning));
+		if (is_inside_tree()) {
+			add_to_group("_world_environment_" + itos(get_viewport()->find_world_3d()->get_scenario().get_id()));
+		}
 	}
 
 	if (is_inside_tree()) {
@@ -207,6 +216,20 @@ PackedStringArray WorldEnvironment::get_configuration_warnings() const {
 	return warnings;
 }
 
+void WorldEnvironment::_check_sky_warning() {
+	if ((environment.is_valid() && !environment->get_sky().is_valid()) || !is_inside_tree()) {
+		return;
+	}
+	Viewport *viewport = get_viewport();
+	if (viewport->get_parent_viewport() == get_tree()->get_root() || String(get_name()).begins_with("@")) {
+		if (GLOBAL_GET("rendering/viewport/transparent_background")) {
+			WARN_PRINT("Environment sky will not render when transparent background is active in project settings.");
+		}
+	} else if (viewport->has_transparent_background()) {
+		WARN_PRINT("Environment sky will not render when transparent background is active in subviewport.");
+	}
+}
+
 void WorldEnvironment::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_environment", "env"), &WorldEnvironment::set_environment);
 	ClassDB::bind_method(D_METHOD("get_environment"), &WorldEnvironment::get_environment);
@@ -223,3 +246,9 @@ void WorldEnvironment::_bind_methods() {
 
 WorldEnvironment::WorldEnvironment() {
 }
+
+WorldEnvironment::~WorldEnvironment() {
+	if (environment.is_valid() && !environment->get_sky().is_valid()) {
+		environment->disconnect(StringName("sky_changed"), callable_mp(this, &WorldEnvironment::_check_sky_warning));
+	}
+}
diff --git a/scene/3d/world_environment.h b/scene/3d/world_environment.h
index 53a695d7de4f..f17d161bd8a4 100644
--- a/scene/3d/world_environment.h
+++ b/scene/3d/world_environment.h
@@ -46,6 +46,7 @@ class WorldEnvironment : public Node {
 	void _update_current_environment();
 	void _update_current_camera_attributes();
 	void _update_current_compositor();
+	void _check_sky_warning();
 
 protected:
 	void _notification(int p_what);
@@ -64,6 +65,7 @@ class WorldEnvironment : public Node {
 	PackedStringArray get_configuration_warnings() const override;
 
 	WorldEnvironment();
+	~WorldEnvironment();
 };
 
 #endif // WORLD_ENVIRONMENT_H
diff --git a/scene/resources/environment.cpp b/scene/resources/environment.cpp
index f8c70c3002aa..3182788fb652 100644
--- a/scene/resources/environment.cpp
+++ b/scene/resources/environment.cpp
@@ -59,6 +59,7 @@ void Environment::set_sky(const Ref<Sky> &p_sky) {
 	if (bg_sky.is_valid()) {
 		sb_rid = bg_sky->get_rid();
 	}
+	emit_signal(StringName("sky_changed"));
 	RS::get_singleton()->environment_set_sky(environment, sb_rid);
 }
 
@@ -1596,6 +1597,9 @@ void Environment::_bind_methods() {
 	BIND_ENUM_CONSTANT(SDFGI_Y_SCALE_50_PERCENT);
 	BIND_ENUM_CONSTANT(SDFGI_Y_SCALE_75_PERCENT);
 	BIND_ENUM_CONSTANT(SDFGI_Y_SCALE_100_PERCENT);
+
+	// Signals
+	ADD_SIGNAL(MethodInfo("sky_changed"));
 }
 
 Environment::Environment() {