Merge pull request #53992 from Calinou/hard-shadow-mapping-allow-dithering

6 files changed, 41 insertions, 16 deletions

diff --git a/doc/classes/ProjectSettings.xml b/doc/classes/ProjectSettings.xml
index 29284d8e43..c646380bee 100644
--- a/doc/classes/ProjectSettings.xml
+++ b/doc/classes/ProjectSettings.xml
@@ -1699,8 +1699,10 @@
 		<member name="rendering/shadows/directional_shadow/size.mobile" type="int" setter="" getter="" default="2048">
 			Lower-end override for [member rendering/shadows/directional_shadow/size] on mobile devices, due to performance concerns or driver support.
 		</member>
-		<member name="rendering/shadows/directional_shadow/soft_shadow_quality" type="int" setter="" getter="" default="2">
+		<member name="rendering/shadows/directional_shadow/soft_shadow_quality" type="int" setter="" getter="" default="3">
 			Quality setting for shadows cast by [DirectionalLight3D]s. Higher quality settings use more samples when reading from shadow maps and are thus slower. Low quality settings may result in shadows looking grainy.
+			[b]Note:[/b] The Soft Very Low setting will automatically multiply [i]constant[/i] shadow blur by 0.75x to reduce the amount of noise visible. This automatic blur change only affects the constant blur factor defined in [member Light3D.shadow_blur], not the variable blur performed by [DirectionalLight3D]s' [member Light3D.light_angular_distance].
+			[b]Note:[/b] The Soft High and Soft Ultra settings will automatically multiply [i]constant[/i] shadow blur by 1.5× and 2× respectively to make better use of the increased sample count. This increased blur also improves stability of dynamic object shadows.
 		</member>
 		<member name="rendering/shadows/directional_shadow/soft_shadow_quality.mobile" type="int" setter="" getter="" default="0">
 			Lower-end override for [member rendering/shadows/directional_shadow/soft_shadow_quality] on mobile devices, due to performance concerns or driver support.
@@ -1725,8 +1727,10 @@
 		<member name="rendering/shadows/shadow_atlas/size.mobile" type="int" setter="" getter="" default="2048">
 			Lower-end override for [member rendering/shadows/shadow_atlas/size] on mobile devices, due to performance concerns or driver support.
 		</member>
-		<member name="rendering/shadows/shadows/soft_shadow_quality" type="int" setter="" getter="" default="2">
+		<member name="rendering/shadows/shadows/soft_shadow_quality" type="int" setter="" getter="" default="3">
 			Quality setting for shadows cast by [OmniLight3D]s and [SpotLight3D]s. Higher quality settings use more samples when reading from shadow maps and are thus slower. Low quality settings may result in shadows looking grainy.
+			[b]Note:[/b] The Soft Very Low setting will automatically multiply [i]constant[/i] shadow blur by 0.75x to reduce the amount of noise visible. This automatic blur change only affects the constant blur factor defined in [member Light3D.shadow_blur], not the variable blur performed by [DirectionalLight3D]s' [member Light3D.light_angular_distance].
+			[b]Note:[/b] The Soft High and Soft Ultra settings will automatically multiply shadow blur by 1.5× and 2× respectively to make better use of the increased sample count. This increased blur also improves stability of dynamic object shadows.
 		</member>
 		<member name="rendering/shadows/shadows/soft_shadow_quality.mobile" type="int" setter="" getter="" default="0">
 			Lower-end override for [member rendering/shadows/shadows/soft_shadow_quality] on mobile devices, due to performance concerns or driver support.
diff --git a/doc/classes/RenderingServer.xml b/doc/classes/RenderingServer.xml
index 6f19114c16..973f8cdb1e 100644
--- a/doc/classes/RenderingServer.xml
+++ b/doc/classes/RenderingServer.xml
@@ -3663,16 +3663,25 @@
 			Use 4 splits for shadow projection when using directional light.
 		</constant>
 		<constant name="SHADOW_QUALITY_HARD" value="0" enum="ShadowQuality">
+			Lowest shadow filtering quality (fastest). Soft shadows are not available with this quality setting, which means the [member Light3D.shadow_blur] property is ignored if [member Light3D.light_size] and [member Light3D.light_angular_distance] is [code]0.0[/code].
+			[b]Note:[/b] The variable shadow blur performed by [member Light3D.light_size] and [member Light3D.light_angular_distance] is still effective when using hard shadow filtering. In this case, [member Light3D.shadow_blur] [i]is[/i] taken into account. However, the results will not be blurred, instead the blur amount is treated as a maximum radius for the penumbra.
 		</constant>
-		<constant name="SHADOW_QUALITY_SOFT_LOW" value="1" enum="ShadowQuality">
+		<constant name="SHADOW_QUALITY_SOFT_VERY_LOW" value="1" enum="ShadowQuality">
+			Very low shadow filtering quality (faster). When using this quality setting, [member Light3D.shadow_blur] is automatically multiplied by 0.75× to avoid introducing too much noise. This division only applies to lights whose [member Light3D.light_size] or [member Light3D.light_angular_distance] is [code]0.0[/code]).
 		</constant>
-		<constant name="SHADOW_QUALITY_SOFT_MEDIUM" value="2" enum="ShadowQuality">
+		<constant name="SHADOW_QUALITY_SOFT_LOW" value="2" enum="ShadowQuality">
+			Low shadow filtering quality (fast).
 		</constant>
-		<constant name="SHADOW_QUALITY_SOFT_HIGH" value="3" enum="ShadowQuality">
+		<constant name="SHADOW_QUALITY_SOFT_MEDIUM" value="3" enum="ShadowQuality">
+			Medium low shadow filtering quality (average).
 		</constant>
-		<constant name="SHADOW_QUALITY_SOFT_ULTRA" value="4" enum="ShadowQuality">
+		<constant name="SHADOW_QUALITY_SOFT_HIGH" value="4" enum="ShadowQuality">
+			High low shadow filtering quality (slow). When using this quality setting, [member Light3D.shadow_blur] is automatically multiplied by 1.5× to better make use of the high sample count. This increased blur also improves the stability of dynamic object shadows. This multiplier only applies to lights whose [member Light3D.light_size] or [member Light3D.light_angular_distance] is [code]0.0[/code]).
 		</constant>
-		<constant name="SHADOW_QUALITY_MAX" value="5" enum="ShadowQuality">
+		<constant name="SHADOW_QUALITY_SOFT_ULTRA" value="5" enum="ShadowQuality">
+			Highest low shadow filtering quality (slowest). When using this quality setting, [member Light3D.shadow_blur] is automatically multiplied by 2× to better make use of the high sample count. This increased blur also improves the stability of dynamic object shadows. This multiplier only applies to lights whose [member Light3D.light_size] or [member Light3D.light_angular_distance] is [code]0.0[/code]).
+		</constant>
+		<constant name="SHADOW_QUALITY_MAX" value="6" enum="ShadowQuality">
 		</constant>
 		<constant name="REFLECTION_PROBE_UPDATE_ONCE" value="0" enum="ReflectionProbeUpdateMode">
 			Reflection probe will update reflections once and then stop.
diff --git a/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp b/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp
index d128578d0b..a906a853dc 100644
--- a/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp
+++ b/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp
@@ -2696,9 +2696,14 @@ void RendererSceneRenderRD::shadows_quality_set(RS::ShadowQuality p_quality) {
 		switch (shadows_quality) {
 			case RS::SHADOW_QUALITY_HARD: {
 				penumbra_shadow_samples = 4;
-				soft_shadow_samples = 1;
+				soft_shadow_samples = 0;
 				shadows_quality_radius = 1.0;
 			} break;
+			case RS::SHADOW_QUALITY_SOFT_VERY_LOW: {
+				penumbra_shadow_samples = 4;
+				soft_shadow_samples = 1;
+				shadows_quality_radius = 1.5;
+			} break;
 			case RS::SHADOW_QUALITY_SOFT_LOW: {
 				penumbra_shadow_samples = 8;
 				soft_shadow_samples = 4;
@@ -2738,9 +2743,14 @@ void RendererSceneRenderRD::directional_shadow_quality_set(RS::ShadowQuality p_q
 		switch (directional_shadow_quality) {
 			case RS::SHADOW_QUALITY_HARD: {
 				directional_penumbra_shadow_samples = 4;
-				directional_soft_shadow_samples = 1;
+				directional_soft_shadow_samples = 0;
 				directional_shadow_quality_radius = 1.0;
 			} break;
+			case RS::SHADOW_QUALITY_SOFT_VERY_LOW: {
+				directional_penumbra_shadow_samples = 4;
+				directional_soft_shadow_samples = 1;
+				directional_shadow_quality_radius = 1.5;
+			} break;
 			case RS::SHADOW_QUALITY_SOFT_LOW: {
 				directional_penumbra_shadow_samples = 8;
 				directional_soft_shadow_samples = 4;
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl
index 4d466342f8..72872c9c08 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl
@@ -301,7 +301,7 @@ float sample_directional_pcf_shadow(texture2D shadow, vec2 shadow_pixel_size, ve
 	float depth = coord.z;
 
 	//if only one sample is taken, take it from the center
-	if (sc_directional_soft_shadow_samples == 1) {
+	if (sc_directional_soft_shadow_samples == 0) {
 		return textureProj(sampler2DShadow(shadow, shadow_sampler), vec4(pos, depth, 1.0));
 	}
 
@@ -327,7 +327,7 @@ float sample_pcf_shadow(texture2D shadow, vec2 shadow_pixel_size, vec3 coord) {
 	float depth = coord.z;
 
 	//if only one sample is taken, take it from the center
-	if (sc_soft_shadow_samples == 1) {
+	if (sc_soft_shadow_samples == 0) {
 		return textureProj(sampler2DShadow(shadow, shadow_sampler), vec4(pos, depth, 1.0));
 	}
 
@@ -350,7 +350,7 @@ float sample_pcf_shadow(texture2D shadow, vec2 shadow_pixel_size, vec3 coord) {
 
 float sample_omni_pcf_shadow(texture2D shadow, float blur_scale, vec2 coord, vec4 uv_rect, vec2 flip_offset, float depth) {
 	//if only one sample is taken, take it from the center
-	if (sc_soft_shadow_samples == 1) {
+	if (sc_soft_shadow_samples == 0) {
 		vec2 pos = coord * 0.5 + 0.5;
 		pos = uv_rect.xy + pos * uv_rect.zw;
 		return textureProj(sampler2DShadow(shadow, shadow_sampler), vec4(pos, depth, 1.0));
diff --git a/servers/rendering_server.cpp b/servers/rendering_server.cpp
index 348d46545b..039dbc71e3 100644
--- a/servers/rendering_server.cpp
+++ b/servers/rendering_server.cpp
@@ -1942,6 +1942,7 @@ void RenderingServer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("directional_shadow_atlas_set_size", "size", "is_16bits"), &RenderingServer::directional_shadow_atlas_set_size);
 
 	BIND_ENUM_CONSTANT(SHADOW_QUALITY_HARD);
+	BIND_ENUM_CONSTANT(SHADOW_QUALITY_SOFT_VERY_LOW);
 	BIND_ENUM_CONSTANT(SHADOW_QUALITY_SOFT_LOW);
 	BIND_ENUM_CONSTANT(SHADOW_QUALITY_SOFT_MEDIUM);
 	BIND_ENUM_CONSTANT(SHADOW_QUALITY_SOFT_HIGH);
@@ -2793,14 +2794,14 @@ RenderingServer::RenderingServer() {
 	GLOBAL_DEF("rendering/shadows/directional_shadow/size", 4096);
 	GLOBAL_DEF("rendering/shadows/directional_shadow/size.mobile", 2048);
 	ProjectSettings::get_singleton()->set_custom_property_info("rendering/shadows/directional_shadow/size", PropertyInfo(Variant::INT, "rendering/shadows/directional_shadow/size", PROPERTY_HINT_RANGE, "256,16384"));
-	GLOBAL_DEF("rendering/shadows/directional_shadow/soft_shadow_quality", 2);
+	GLOBAL_DEF("rendering/shadows/directional_shadow/soft_shadow_quality", 3);
 	GLOBAL_DEF("rendering/shadows/directional_shadow/soft_shadow_quality.mobile", 0);
-	ProjectSettings::get_singleton()->set_custom_property_info("rendering/shadows/directional_shadow/soft_shadow_quality", PropertyInfo(Variant::INT, "rendering/shadows/directional_shadow/soft_shadow_quality", PROPERTY_HINT_ENUM, "Hard (Fastest),Soft Low (Fast),Soft Medium (Average),Soft High (Slow),Soft Ultra (Slowest)"));
+	ProjectSettings::get_singleton()->set_custom_property_info("rendering/shadows/directional_shadow/soft_shadow_quality", PropertyInfo(Variant::INT, "rendering/shadows/directional_shadow/soft_shadow_quality", PROPERTY_HINT_ENUM, "Hard (Fastest),Soft Very Low (Faster),Soft Low (Fast),Soft Medium (Average),Soft High (Slow),Soft Ultra (Slowest)"));
 	GLOBAL_DEF("rendering/shadows/directional_shadow/16_bits", true);
 
-	GLOBAL_DEF("rendering/shadows/shadows/soft_shadow_quality", 2);
+	GLOBAL_DEF("rendering/shadows/shadows/soft_shadow_quality", 3);
 	GLOBAL_DEF("rendering/shadows/shadows/soft_shadow_quality.mobile", 0);
-	ProjectSettings::get_singleton()->set_custom_property_info("rendering/shadows/shadows/soft_shadow_quality", PropertyInfo(Variant::INT, "rendering/shadows/shadows/soft_shadow_quality", PROPERTY_HINT_ENUM, "Hard (Fastest),Soft Low (Fast),Soft Medium (Average),Soft High (Slow),Soft Ultra (Slowest)"));
+	ProjectSettings::get_singleton()->set_custom_property_info("rendering/shadows/shadows/soft_shadow_quality", PropertyInfo(Variant::INT, "rendering/shadows/shadows/soft_shadow_quality", PROPERTY_HINT_ENUM, "Hard (Fastest),Soft Very Low (Faster),Soft Low (Fast),Soft Medium (Average),Soft High (Slow),Soft Ultra (Slowest)"));
 
 	GLOBAL_DEF("rendering/2d/shadow_atlas/size", 2048);
 
diff --git a/servers/rendering_server.h b/servers/rendering_server.h
index b50da66d03..b6068afcf1 100644
--- a/servers/rendering_server.h
+++ b/servers/rendering_server.h
@@ -474,6 +474,7 @@ public:
 
 	enum ShadowQuality {
 		SHADOW_QUALITY_HARD,
+		SHADOW_QUALITY_SOFT_VERY_LOW,
 		SHADOW_QUALITY_SOFT_LOW,
 		SHADOW_QUALITY_SOFT_MEDIUM,
 		SHADOW_QUALITY_SOFT_HIGH,