Add a per-light volumetric fog energy property

Per-light energy gives more control to the user on the final result of
volumetric fog. Specific lights can be fully excluded from volumetric fog
by setting their volumetric fog energy to 0, which improves performance
slightly. This can also be used to prevent short-lived dynamic effects
from poorly interacting with volumetric fog, as it's updated over several
frames by default unless temporal reprojection is disabled.

Volumetric fog shadows now obey Light3D's Shadow Opacity property as well.

The shadow fog fade property was removed as it had little visible impact
on the final scene's rendering.

2 files changed, 5 insertions, 5 deletions

diff --git a/scene/3d/light_3d.cpp b/scene/3d/light_3d.cpp
index 8d96d13f0c..66f4fa2bcc 100644
--- a/scene/3d/light_3d.cpp
+++ b/scene/3d/light_3d.cpp
@@ -224,7 +224,7 @@ bool Light3D::is_editor_only() const {
 }
 
 void Light3D::_validate_property(PropertyInfo &p_property) const {
-	if (!shadow && (p_property.name == "shadow_bias" || p_property.name == "shadow_normal_bias" || p_property.name == "shadow_reverse_cull_face" || p_property.name == "shadow_transmittance_bias" || p_property.name == "shadow_fog_fade" || p_property.name == "shadow_opacity" || p_property.name == "shadow_blur" || p_property.name == "distance_fade_shadow")) {
+	if (!shadow && (p_property.name == "shadow_bias" || p_property.name == "shadow_normal_bias" || p_property.name == "shadow_reverse_cull_face" || p_property.name == "shadow_transmittance_bias" || p_property.name == "shadow_opacity" || p_property.name == "shadow_blur" || p_property.name == "distance_fade_shadow")) {
 		p_property.usage = PROPERTY_USAGE_NO_EDITOR;
 	}
 
@@ -282,6 +282,7 @@ void Light3D::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::COLOR, "light_color", PROPERTY_HINT_COLOR_NO_ALPHA), "set_color", "get_color");
 	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "light_energy", PROPERTY_HINT_RANGE, "0,16,0.001,or_greater"), "set_param", "get_param", PARAM_ENERGY);
 	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "light_indirect_energy", PROPERTY_HINT_RANGE, "0,16,0.001,or_greater"), "set_param", "get_param", PARAM_INDIRECT_ENERGY);
+	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "light_volumetric_fog_energy", PROPERTY_HINT_RANGE, "0,16,0.001,or_greater"), "set_param", "get_param", PARAM_VOLUMETRIC_FOG_ENERGY);
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "light_projector", PROPERTY_HINT_RESOURCE_TYPE, "Texture2D"), "set_projector", "get_projector");
 	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "light_size", PROPERTY_HINT_RANGE, "0,1,0.001,or_greater,suffix:m"), "set_param", "get_param", PARAM_SIZE);
 	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "light_angular_distance", PROPERTY_HINT_RANGE, "0,90,0.01,degrees"), "set_param", "get_param", PARAM_SIZE);
@@ -296,7 +297,6 @@ void Light3D::_bind_methods() {
 	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "shadow_normal_bias", PROPERTY_HINT_RANGE, "0,10,0.001"), "set_param", "get_param", PARAM_SHADOW_NORMAL_BIAS);
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "shadow_reverse_cull_face"), "set_shadow_reverse_cull_face", "get_shadow_reverse_cull_face");
 	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "shadow_transmittance_bias", PROPERTY_HINT_RANGE, "-16,16,0.001"), "set_param", "get_param", PARAM_TRANSMITTANCE_BIAS);
-	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "shadow_fog_fade", PROPERTY_HINT_RANGE, "0.001,10,0.001"), "set_param", "get_param", PARAM_SHADOW_VOLUMETRIC_FOG_FADE);
 	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "shadow_opacity", PROPERTY_HINT_RANGE, "0,1,0.01"), "set_param", "get_param", PARAM_SHADOW_OPACITY);
 	ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "shadow_blur", PROPERTY_HINT_RANGE, "0,10,0.001"), "set_param", "get_param", PARAM_SHADOW_BLUR);
 
@@ -313,6 +313,7 @@ void Light3D::_bind_methods() {
 
 	BIND_ENUM_CONSTANT(PARAM_ENERGY);
 	BIND_ENUM_CONSTANT(PARAM_INDIRECT_ENERGY);
+	BIND_ENUM_CONSTANT(PARAM_VOLUMETRIC_FOG_ENERGY);
 	BIND_ENUM_CONSTANT(PARAM_SPECULAR);
 	BIND_ENUM_CONSTANT(PARAM_RANGE);
 	BIND_ENUM_CONSTANT(PARAM_SIZE);
@@ -329,7 +330,6 @@ void Light3D::_bind_methods() {
 	BIND_ENUM_CONSTANT(PARAM_SHADOW_PANCAKE_SIZE);
 	BIND_ENUM_CONSTANT(PARAM_SHADOW_OPACITY);
 	BIND_ENUM_CONSTANT(PARAM_SHADOW_BLUR);
-	BIND_ENUM_CONSTANT(PARAM_SHADOW_VOLUMETRIC_FOG_FADE);
 	BIND_ENUM_CONSTANT(PARAM_TRANSMITTANCE_BIAS);
 	BIND_ENUM_CONSTANT(PARAM_MAX);
 
@@ -363,6 +363,7 @@ Light3D::Light3D(RenderingServer::LightType p_type) {
 
 	set_param(PARAM_ENERGY, 1);
 	set_param(PARAM_INDIRECT_ENERGY, 1);
+	set_param(PARAM_VOLUMETRIC_FOG_ENERGY, 1);
 	set_param(PARAM_SPECULAR, 0.5);
 	set_param(PARAM_RANGE, 5);
 	set_param(PARAM_SIZE, 0);
@@ -380,7 +381,6 @@ Light3D::Light3D(RenderingServer::LightType p_type) {
 	set_param(PARAM_SHADOW_BIAS, 0.03);
 	set_param(PARAM_SHADOW_NORMAL_BIAS, 1.0);
 	set_param(PARAM_TRANSMITTANCE_BIAS, 0.05);
-	set_param(PARAM_SHADOW_VOLUMETRIC_FOG_FADE, 0.1);
 	set_param(PARAM_SHADOW_FADE_START, 1);
 	set_disable_scale(true);
 }
diff --git a/scene/3d/light_3d.h b/scene/3d/light_3d.h
index 035ba50e42..0792f21c6e 100644
--- a/scene/3d/light_3d.h
+++ b/scene/3d/light_3d.h
@@ -40,6 +40,7 @@ public:
 	enum Param {
 		PARAM_ENERGY = RS::LIGHT_PARAM_ENERGY,
 		PARAM_INDIRECT_ENERGY = RS::LIGHT_PARAM_INDIRECT_ENERGY,
+		PARAM_VOLUMETRIC_FOG_ENERGY = RS::LIGHT_PARAM_VOLUMETRIC_FOG_ENERGY,
 		PARAM_SPECULAR = RS::LIGHT_PARAM_SPECULAR,
 		PARAM_RANGE = RS::LIGHT_PARAM_RANGE,
 		PARAM_SIZE = RS::LIGHT_PARAM_SIZE,
@@ -56,7 +57,6 @@ public:
 		PARAM_SHADOW_PANCAKE_SIZE = RS::LIGHT_PARAM_SHADOW_PANCAKE_SIZE,
 		PARAM_SHADOW_OPACITY = RS::LIGHT_PARAM_SHADOW_OPACITY,
 		PARAM_SHADOW_BLUR = RS::LIGHT_PARAM_SHADOW_BLUR,
-		PARAM_SHADOW_VOLUMETRIC_FOG_FADE = RS::LIGHT_PARAM_SHADOW_VOLUMETRIC_FOG_FADE,
 		PARAM_TRANSMITTANCE_BIAS = RS::LIGHT_PARAM_TRANSMITTANCE_BIAS,
 		PARAM_MAX = RS::LIGHT_PARAM_MAX
 	};