add microshadows

Author: LiveTrower

doc/classes/BaseMaterial3D.xml

@@ -102,6 +102,12 @@
 		<member name="ao_light_affect" type="float" setter="set_ao_light_affect" getter="get_ao_light_affect" default="0.0">
 			Amount that ambient occlusion affects lighting from lights. If [code]0[/code], ambient occlusion only affects ambient light. If [code]1[/code], ambient occlusion affects lights just as much as it affects ambient light. This can be used to impact the strength of the ambient occlusion effect, but typically looks unrealistic.
 		</member>
+		<member name="ao_micro_shadows" type="float" setter="set_micro_shadows" getter="get_micro_shadows" default="0.85">
+			Amount of micro shadowing applied to ambient occlusion. Higher values result in more shadowing in crevices and corners, while lower values result in less shadowing. This can help improve the appearance of ambient occlusion by simulating small details embedded in the materials.
+			[b]Note:[/b] This setting only has an effect if directional lights are present in the scene. It does not work with [OmniLight3D] and [SpotLight3D].
+			[b]Note:[/b] For best results, this setting requires an [member ao_texture] and a [member normal_texture] generated with the same pipeline.
+			[b]Note:[/b] This setting can serve as a PBR alternative to [member ao_light_affect].
+		</member>
 		<member name="ao_on_uv2" type="bool" setter="set_flag" getter="get_flag" default="false">
 			If [code]true[/code], use [code]UV2[/code] coordinates to look up from the [member ao_texture].
 		</member>

drivers/gles3/shaders/scene.glsl

@@ -1493,6 +1493,13 @@ float SchlickFresnel(float u) {
 	return m2 * m2 * m; // pow(m,5)
 }
 
+// Brinck and Maximov 2016, "The Technical Art of Uncharted 4"
+float compute_micro_shadowing(float NoL, float ao, float opacity) {
+	float aperture = 2.0 * ao * ao;
+	float microshadow = clamp(NoL + aperture - 1.0, 0.0, 1.0);
+	return mix(1.0, microshadow, opacity);
+}
+
 void light_compute(vec3 N, vec3 L, vec3 V, float A, vec3 light_color, bool is_directional, float attenuation, vec3 f0, float roughness, float metallic, float specular_amount, vec3 albedo, inout float alpha, vec2 screen_uv,
 #ifdef LIGHT_BACKLIGHT_USED
 		vec3 backlight,
@@ -2013,7 +2020,9 @@ void main() {
 #endif
 
 	float ao = 1.0;
+	float direct_ao = 0.0;
 	float ao_light_affect = 0.0;
+	float micro_shadows = 0.0;
 
 	float alpha = 1.0;
 
@@ -2349,7 +2358,7 @@ void main() {
 #endif // !AMBIENT_LIGHT_DISABLED
 
 	// convert ao to direct light ao
-	ao = mix(1.0, ao, ao_light_affect);
+	direct_ao = mix(1.0, ao, ao_light_affect);
 #ifndef AMBIENT_LIGHT_DISABLED
 	{
 #if defined(DIFFUSE_TOON)
@@ -2503,7 +2512,7 @@ void main() {
 	normal_output_buffer.rgb = normal * 0.5 + 0.5;
 	normal_output_buffer.a = 0.0;
 
-	orm_output_buffer.r = ao;
+	orm_output_buffer.r = direct_ao;
 	orm_output_buffer.g = roughness;
 	orm_output_buffer.b = metallic;
 	orm_output_buffer.a = 1.0;
@@ -2701,6 +2710,12 @@ void main() {
 	float directional_shadow = 1.0f;
 #endif // SHADOWS_DISABLED
 
+#ifdef MICRO_SHADOWS_USED
+	float NdotL = dot(normal, directional_lights[directional_shadow_index].direction);
+	// Disable microshadowing when facing away from light.
+	directional_shadow *= NdotL >= 0.0 ? compute_micro_shadowing(NdotL, ao, micro_shadows) : 1.0;
+#endif
+
 #ifndef USE_VERTEX_LIGHTING
 	if (bool(directional_lights[directional_shadow_index].mask & layer_mask)) {
 		light_compute(normal, normalize(directional_lights[directional_shadow_index].direction), normalize(view), directional_lights[directional_shadow_index].size, directional_lights[directional_shadow_index].color * directional_lights[directional_shadow_index].energy, true, directional_shadow, f0, roughness, metallic, directional_lights[directional_shadow_index].specular, albedo, alpha, screen_uv,

drivers/gles3/storage/material_storage.cpp

@@ -1306,6 +1306,7 @@ MaterialStorage::MaterialStorage() {
 		actions.renames["BACKLIGHT"] = "backlight";
 		actions.renames["AO"] = "ao";
 		actions.renames["AO_LIGHT_AFFECT"] = "ao_light_affect";
+		actions.renames["MICRO_SHADOWS"] = "micro_shadows";
 		actions.renames["EMISSION"] = "emission";
 		actions.renames["POINT_COORD"] = "gl_PointCoord";
 		actions.renames["INSTANCE_CUSTOM"] = "instance_custom";
@@ -1354,6 +1355,7 @@ MaterialStorage::MaterialStorage() {
 		actions.usage_defines["ANISOTROPY_FLOW"] = "@ANISOTROPY";
 		actions.usage_defines["AO"] = "#define AO_USED\n";
 		actions.usage_defines["AO_LIGHT_AFFECT"] = "#define AO_USED\n";
+		actions.usage_defines["MICRO_SHADOWS"] = "#define MICRO_SHADOWS_USED\n";
 		actions.usage_defines["UV"] = "#define UV_USED\n";
 		actions.usage_defines["UV2"] = "#define UV2_USED\n";
 		actions.usage_defines["BONE_INDICES"] = "#define BONES_USED\n";

scene/resources/material.cpp

@@ -623,6 +623,7 @@ void BaseMaterial3D::init_shaders() {
 	shader_names->grow = "grow";
 
 	shader_names->ao_light_affect = "ao_light_affect";
+	shader_names->micro_shadows = "micro_shadows";
 
 	shader_names->proximity_fade_distance = "proximity_fade_distance";
 	shader_names->distance_fade_min = "distance_fade_min";
@@ -1128,6 +1129,7 @@ uniform sampler2D texture_flowmap : hint_anisotropy, %s;
 uniform sampler2D texture_ambient_occlusion : hint_default_white, %s;
 uniform vec4 ao_texture_channel;
 uniform float ao_light_affect : hint_range(0.0, 1.0, 0.01);
+uniform float micro_shadows : hint_range(0.0, 1.0, 0.01);
 )",
 				texfilter_str);
 	}
@@ -1949,6 +1951,7 @@ void fragment() {)";
 		}
 
 		code += "	AO_LIGHT_AFFECT = ao_light_affect;\n";
+		code += "	MICRO_SHADOWS = micro_shadows;\n";
 	}
 
 	if (features[FEATURE_SUBSURFACE_SCATTERING]) {
@@ -2245,6 +2248,15 @@ float BaseMaterial3D::get_ao_light_affect() const {
 	return ao_light_affect;
 }
 
+void BaseMaterial3D::set_micro_shadows(float p_micro_shadows) {
+	micro_shadows = p_micro_shadows;
+	_material_set_param(shader_names->micro_shadows, p_micro_shadows);
+}
+
+float BaseMaterial3D::get_micro_shadows() const {
+	return micro_shadows;
+}
+
 void BaseMaterial3D::set_clearcoat(float p_clearcoat) {
 	clearcoat = p_clearcoat;
 	_material_set_param(shader_names->clearcoat, p_clearcoat);
@@ -3508,6 +3520,9 @@ void BaseMaterial3D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_ao_light_affect", "amount"), &BaseMaterial3D::set_ao_light_affect);
 	ClassDB::bind_method(D_METHOD("get_ao_light_affect"), &BaseMaterial3D::get_ao_light_affect);
 
+	ClassDB::bind_method(D_METHOD("set_micro_shadows", "amount"), &BaseMaterial3D::set_micro_shadows);
+	ClassDB::bind_method(D_METHOD("get_micro_shadows"), &BaseMaterial3D::get_micro_shadows);
+
 	ClassDB::bind_method(D_METHOD("set_alpha_scissor_threshold", "threshold"), &BaseMaterial3D::set_alpha_scissor_threshold);
 	ClassDB::bind_method(D_METHOD("get_alpha_scissor_threshold"), &BaseMaterial3D::get_alpha_scissor_threshold);
 
@@ -3657,6 +3672,7 @@ void BaseMaterial3D::_bind_methods() {
 	ADD_GROUP("Ambient Occlusion", "ao_");
 	ADD_PROPERTYI(PropertyInfo(Variant::BOOL, "ao_enabled", PROPERTY_HINT_GROUP_ENABLE), "set_feature", "get_feature", FEATURE_AMBIENT_OCCLUSION);
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "ao_light_affect", PROPERTY_HINT_RANGE, "0,1,0.01"), "set_ao_light_affect", "get_ao_light_affect");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "ao_micro_shadows", PROPERTY_HINT_RANGE, "0,1,0.01"), "set_micro_shadows", "get_micro_shadows");
 	ADD_PROPERTYI(PropertyInfo(Variant::OBJECT, "ao_texture", PROPERTY_HINT_RESOURCE_TYPE, "Texture2D"), "set_texture", "get_texture", TEXTURE_AMBIENT_OCCLUSION);
 	ADD_PROPERTYI(PropertyInfo(Variant::BOOL, "ao_on_uv2"), "set_flag", "get_flag", FLAG_AO_ON_UV2);
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "ao_texture_channel", PROPERTY_HINT_ENUM, "Red,Green,Blue,Alpha,Gray"), "set_ao_texture_channel", "get_ao_texture_channel");
@@ -3971,6 +3987,7 @@ BaseMaterial3D::BaseMaterial3D(bool p_orm) :
 	set_distance_fade_max_distance(10);
 
 	set_ao_light_affect(0.0);
+	set_micro_shadows(0.85);
 
 	set_metallic_texture_channel(TEXTURE_CHANNEL_RED);
 	set_roughness_texture_channel(TEXTURE_CHANNEL_RED);

scene/resources/material.h

@@ -502,6 +502,7 @@ class BaseMaterial3D : public Material {
 		StringName distance_fade_min;
 		StringName distance_fade_max;
 		StringName ao_light_affect;
+		StringName micro_shadows;
 
 		StringName metallic_texture_channel;
 		StringName ao_texture_channel;
@@ -564,6 +565,7 @@ class BaseMaterial3D : public Material {
 	float alpha_antialiasing_edge = 0.0f;
 	bool grow_enabled = false;
 	float ao_light_affect = 0.0f;
+	float micro_shadows = 0.85f;
 	float grow = 0.0f;
 	int particles_anim_h_frames = 0;
 	int particles_anim_v_frames = 0;
@@ -677,6 +679,9 @@ class BaseMaterial3D : public Material {
 	void set_ao_light_affect(float p_ao_light_affect);
 	float get_ao_light_affect() const;
 
+	void set_micro_shadows(float p_micro_shadows);
+	float get_micro_shadows() const;
+
 	void set_clearcoat(float p_clearcoat);
 	float get_clearcoat() const;
 

servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp

@@ -747,6 +747,7 @@ void SceneShaderForwardClustered::init(const String p_defines) {
 		actions.renames["BACKLIGHT"] = "backlight";
 		actions.renames["AO"] = "ao";
 		actions.renames["AO_LIGHT_AFFECT"] = "ao_light_affect";
+		actions.renames["MICRO_SHADOWS"] = "micro_shadows";
 		actions.renames["EMISSION"] = "emission";
 		actions.renames["POINT_COORD"] = "gl_PointCoord";
 		actions.renames["INSTANCE_CUSTOM"] = "instance_custom";
@@ -795,6 +796,7 @@ void SceneShaderForwardClustered::init(const String p_defines) {
 		actions.usage_defines["ANISOTROPY_FLOW"] = "@ANISOTROPY";
 		actions.usage_defines["AO"] = "#define AO_USED\n";
 		actions.usage_defines["AO_LIGHT_AFFECT"] = "#define AO_USED\n";
+		actions.usage_defines["MICRO_SHADOWS"] = "#define MICRO_SHADOWS_USED\n";
 		actions.usage_defines["UV"] = "#define UV_USED\n";
 		actions.usage_defines["UV2"] = "#define UV2_USED\n";
 		actions.usage_defines["BONE_INDICES"] = "#define BONES_USED\n";

servers/rendering/renderer_rd/forward_mobile/scene_shader_forward_mobile.cpp

@@ -682,6 +682,7 @@ void SceneShaderForwardMobile::init(const String p_defines) {
 		actions.renames["BACKLIGHT"] = "backlight_highp";
 		actions.renames["AO"] = "ao_highp";
 		actions.renames["AO_LIGHT_AFFECT"] = "ao_light_affect_highp";
+		actions.renames["MICRO_SHADOWS"] = "micro_shadows_highp";
 		actions.renames["EMISSION"] = "emission_highp";
 		actions.renames["POINT_COORD"] = "gl_PointCoord";
 		actions.renames["INSTANCE_CUSTOM"] = "instance_custom";
@@ -730,6 +731,7 @@ void SceneShaderForwardMobile::init(const String p_defines) {
 		actions.usage_defines["ANISOTROPY_FLOW"] = "@ANISOTROPY";
 		actions.usage_defines["AO"] = "#define AO_USED\n";
 		actions.usage_defines["AO_LIGHT_AFFECT"] = "#define AO_USED\n";
+		actions.usage_defines["MICRO_SHADOWS"] = "#define MICRO_SHADOWS_USED\n";
 		actions.usage_defines["UV"] = "#define UV_USED\n";
 		actions.usage_defines["UV2"] = "#define UV2_USED\n";
 		actions.usage_defines["BONE_INDICES"] = "#define BONES_USED\n";

servers/rendering/renderer_rd/shaders/forward_clustered/scene_forward_clustered.glsl

@@ -1203,7 +1203,9 @@ void fragment_shader(in SceneData scene_data) {
 #endif
 
 	float ao = 1.0;
+	float direct_ao = 0.0;
 	float ao_light_affect = 0.0;
+	float micro_shadows = 0.0;
 
 	float alpha_highp = float(instances.data[instance_index].flags >> INSTANCE_FLAGS_FADE_SHIFT) / float(255.0);
 
@@ -2130,7 +2132,7 @@ void fragment_shader(in SceneData scene_data) {
 #endif // AMBIENT_LIGHT_DISABLED
 
 	// convert ao to direct light ao
-	ao = mix(1.0, ao, ao_light_affect);
+	direct_ao = mix(1.0, ao, ao_light_affect);
 
 	//this saves some VGPRs
 	vec3 f0 = F0(metallic, specular, albedo);
@@ -2534,6 +2536,12 @@ void fragment_shader(in SceneData scene_data) {
 			shadow = 1.0;
 #endif
 
+#ifdef MICRO_SHADOWS_USED
+			float NdotL = dot(normal, directional_lights.data[i].direction);
+			// Disable microshadowing when facing away from light.
+			shadow *= NdotL >= 0.0 ? compute_micro_shadowing(NdotL, ao, micro_shadows) : 1.0;
+#endif
+
 			float size_A = sc_use_directional_soft_shadows() ? directional_lights.data[i].size : 0.0;
 
 			light_compute(normal, directional_lights.data[i].direction, normalize(view), size_A,
@@ -2820,7 +2828,7 @@ void fragment_shader(in SceneData scene_data) {
 	normal_output_buffer.a = 0.0;
 	depth_output_buffer.r = -vertex.z;
 
-	orm_output_buffer.r = ao;
+	orm_output_buffer.r = direct_ao;
 	orm_output_buffer.g = roughness;
 	orm_output_buffer.b = metallic;
 	orm_output_buffer.a = sss_strength;
@@ -2861,8 +2869,8 @@ void fragment_shader(in SceneData scene_data) {
 	diffuse_light *= albedo; // ambient must be multiplied by albedo at the end
 
 	// apply direct light AO
-	diffuse_light *= ao;
-	direct_specular_light *= ao;
+	diffuse_light *= direct_ao;
+	direct_specular_light *= direct_ao;
 
 	// apply metallic
 	diffuse_light *= 1.0 - metallic;

servers/rendering/renderer_rd/shaders/forward_clustered/scene_forward_clustered_inc.glsl

@@ -470,6 +470,13 @@ vec3 get_energy_compensation(vec3 f0, float env) {
 	return 1.0 + f0 * (1.0 / env - 1.0);
 }
 
+// Brinck and Maximov 2016, "The Technical Art of Uncharted 4"
+float compute_micro_shadowing(float NoL, float ao, float opacity) {
+	float aperture = 2.0 * ao * ao;
+	float microshadow = clamp(NoL + aperture - 1.0, 0.0, 1.0);
+	return mix(1.0, microshadow, opacity);
+}
+
 /* Set 2 Skeleton & Instancing (can change per item) */
 
 layout(set = 2, binding = 0, std430) restrict readonly buffer Transforms {

servers/rendering/renderer_rd/shaders/forward_mobile/scene_forward_mobile.glsl

@@ -1123,7 +1123,9 @@ void main() {
 #endif
 
 	float ao_highp = 1.0;
+	float direct_ao_highp = 0.0;
 	float ao_light_affect_highp = 0.0;
+	float micro_shadows_highp = 0.0;
 
 	float alpha_highp = 1.0;
 
@@ -1234,6 +1236,8 @@ void main() {
 	hvec2 anisotropy_flow = hvec2(anisotropy_flow_highp);
 	half ao = half(ao_highp);
 	half ao_light_affect = half(ao_light_affect_highp);
+	half direct_ao = half(direct_ao_highp);
+	half micro_shadows = half(micro_shadows_highp);
 	half alpha = half(alpha_highp);
 	half normal_map_depth = half(normal_map_depth_highp);
 	half sss_strength = half(sss_strength_highp);
@@ -1786,7 +1790,7 @@ void main() {
 #endif // !AMBIENT_LIGHT_DISABLED
 
 	// convert ao to direct light ao
-	ao = mix(half(1.0), ao, ao_light_affect);
+	direct_ao = mix(half(1.0), ao, ao_light_affect);
 
 	//this saves some VGPRs
 	hvec3 f0 = F0(metallic, specular, albedo);
@@ -2029,6 +2033,12 @@ void main() {
 			shadow = half(1.0);
 #endif
 
+#ifdef MICRO_SHADOWS_USED
+			float NdotL = dot(normal, directional_lights.data[i].direction);
+			// Disable microshadowing when facing away from light.
+			shadow *= NdotL >= 0.0 ? compute_micro_shadowing(NdotL, ao, micro_shadows) : 1.0;
+#endif
+
 			float size_A = sc_use_light_soft_shadows() ? directional_lights.data[i].size : 0.0;
 
 			light_compute(normal, hvec3(directional_lights.data[i].direction), view, saturateHalf(size_A),
@@ -2161,7 +2171,7 @@ void main() {
 	normal_output_buffer.a = 0.0;
 	depth_output_buffer.r = -vertex.z;
 
-	orm_output_buffer.r = ao;
+	orm_output_buffer.r = direct_ao;
 	orm_output_buffer.g = roughness;
 	orm_output_buffer.b = metallic;
 	orm_output_buffer.a = sss_strength;
@@ -2176,8 +2186,8 @@ void main() {
 	diffuse_light *= albedo; // ambient must be multiplied by albedo at the end
 
 	// apply direct light AO
-	diffuse_light *= ao;
-	direct_specular_light *= ao;
+	diffuse_light *= direct_ao;
+	direct_specular_light *= direct_ao;
 
 	// apply metallic
 	diffuse_light *= half(1.0) - metallic;