add support for 3 dir shadow splits

doc/classes/DirectionalLight.xml

@@ -24,7 +24,7 @@
 		<member name="directional_shadow_max_distance" type="float" setter="set_param" getter="get_param" default="100.0">
 			The maximum distance for shadow splits. Increasing this value will make directional shadows visible from further away, at the cost of lower overall shadow detail and performance (since more objects need to be included in the directional shadow rendering).
 		</member>
-		<member name="directional_shadow_mode" type="int" setter="set_shadow_mode" getter="get_shadow_mode" enum="DirectionalLight.ShadowMode" default="2">
+		<member name="directional_shadow_mode" type="int" setter="set_shadow_mode" getter="get_shadow_mode" enum="DirectionalLight.ShadowMode" default="3">
 			The light's shadow rendering algorithm. See [enum ShadowMode].
 		</member>
 		<member name="directional_shadow_normal_bias" type="float" setter="set_param" getter="get_param" default="0.8">
@@ -48,7 +48,10 @@
 		<constant name="SHADOW_PARALLEL_2_SPLITS" value="1" enum="ShadowMode">
 			Splits the view frustum in 2 areas, each with its own shadow map. This shadow mode is a compromise between [constant SHADOW_ORTHOGONAL] and [constant SHADOW_PARALLEL_4_SPLITS] in terms of performance.
 		</constant>
-		<constant name="SHADOW_PARALLEL_4_SPLITS" value="2" enum="ShadowMode">
+		<constant name="SHADOW_PARALLEL_3_SPLITS" value="2" enum="ShadowMode">
+			Splits the view frustum in 3 areas, each with its own shadow map. This shadow mode is a compromise between [constant SHADOW_ORTHOGONAL] and [constant SHADOW_PARALLEL_4_SPLITS] in terms of performance.
+		</constant>
+		<constant name="SHADOW_PARALLEL_4_SPLITS" value="3" enum="ShadowMode">
 			Splits the view frustum in 4 areas, each with its own shadow map. This is the slowest directional shadow mode.
 		</constant>
 		<constant name="SHADOW_DEPTH_RANGE_STABLE" value="0" enum="ShadowDepthRange">

doc/classes/VisualServer.xml

@@ -3581,7 +3581,10 @@
 		<constant name="LIGHT_DIRECTIONAL_SHADOW_PARALLEL_2_SPLITS" value="1" enum="LightDirectionalShadowMode">
 			Use 2 splits for shadow projection when using directional light.
 		</constant>
-		<constant name="LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS" value="2" enum="LightDirectionalShadowMode">
+		<constant name="LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS" value="2" enum="LightDirectionalShadowMode">
+			Use 3 splits for shadow projection when using directional light.
+		</constant>
+		<constant name="LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS" value="3" enum="LightDirectionalShadowMode">
 			Use 4 splits for shadow projection when using directional light.
 		</constant>
 		<constant name="LIGHT_DIRECTIONAL_SHADOW_DEPTH_RANGE_STABLE" value="0" enum="LightDirectionalShadowDepthRangeMode">

drivers/gles2/rasterizer_scene_gles2.cpp

@@ -514,6 +514,7 @@ int RasterizerSceneGLES2::get_directional_light_shadow_size(RID p_light_intance)
 		case VS::LIGHT_DIRECTIONAL_SHADOW_ORTHOGONAL:
 			break; //none
 		case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_2_SPLITS:
+		case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS:
 		case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS:
 			shadow_size /= 2;
 			break;
@@ -1915,6 +1916,7 @@ void RasterizerSceneGLES2::_setup_light_type(LightInstance *p_light, ShadowAtlas
 	state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_MODE_OMNI, false);
 	state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_MODE_SPOT, false);
 	state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM2, false);
+	state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM3, false);
 	state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM4, false);
 	state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM_BLEND, false);
 
@@ -1936,6 +1938,9 @@ void RasterizerSceneGLES2::_setup_light_type(LightInstance *p_light, ShadowAtlas
 					state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM2, true);
 
 				} break;
+				case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS: {
+					state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM3, true);
+				} break;
 				case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS: {
 					state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM4, true);
 				} break;
@@ -2023,6 +2028,10 @@ void RasterizerSceneGLES2::_setup_light(LightInstance *light, ShadowAtlas *shado
 						shadow_count = 2;
 					} break;
 
+					case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS: {
+						shadow_count = 3;
+					} break;
+
 					case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS: {
 						shadow_count = 4;
 					} break;
@@ -2034,7 +2043,7 @@ void RasterizerSceneGLES2::_setup_light(LightInstance *light, ShadowAtlas *shado
 					uint32_t width = light->directional_rect.size.x;
 					uint32_t height = light->directional_rect.size.y;
 
-					if (light_ptr->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS) {
+					if (light_ptr->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS || light_ptr->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS) {
 						width /= 2;
 						height /= 2;
 
@@ -2670,6 +2679,7 @@ void RasterizerSceneGLES2::_render_render_list(RenderList::Element **p_elements,
 	state.scene_shader.set_conditional(SceneShaderGLES2::USE_INSTANCING, false);
 	state.scene_shader.set_conditional(SceneShaderGLES2::USE_RADIANCE_MAP, false);
 	state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM4, false);
+	state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM3, false);
 	state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM2, false);
 	state.scene_shader.set_conditional(SceneShaderGLES2::LIGHT_USE_PSSM_BLEND, false);
 	state.scene_shader.set_conditional(SceneShaderGLES2::USE_VERTEX_LIGHTING, false);
@@ -3717,7 +3727,7 @@ void RasterizerSceneGLES2::render_shadow(RID p_light, RID p_shadow_atlas, int p_
 		width = light_instance->directional_rect.size.width;
 		height = light_instance->directional_rect.size.height;
 
-		if (light->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS) {
+		if (light->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS || light->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS) {
 			width /= 2;
 			height /= 2;
 

drivers/gles2/shaders/scene.glsl

@@ -166,18 +166,19 @@ uniform highp float shadow_dual_paraboloid_render_side;
 uniform highp mat4 light_shadow_matrix;
 varying highp vec4 shadow_coord;
 
-#if defined(LIGHT_USE_PSSM2) || defined(LIGHT_USE_PSSM4)
+#if defined(LIGHT_USE_PSSM2) || defined(LIGHT_USE_PSSM3) || defined(LIGHT_USE_PSSM4)
 uniform highp mat4 light_shadow_matrix2;
 varying highp vec4 shadow_coord2;
 #endif
 
-#if defined(LIGHT_USE_PSSM4)
+#if defined(LIGHT_USE_PSSM3) || defined(LIGHT_USE_PSSM4)
-
 uniform highp mat4 light_shadow_matrix3;
-uniform highp mat4 light_shadow_matrix4;
 varying highp vec4 shadow_coord3;
-varying highp vec4 shadow_coord4;
+#endif
 
+#if defined(LIGHT_USE_PSSM4)
+uniform highp mat4 light_shadow_matrix4;
+varying highp vec4 shadow_coord4;
 #endif
 
 #endif
@@ -625,14 +626,16 @@ VERTEX_SHADER_CODE
 	vec4 vi4 = vec4(vertex_interp, 1.0);
 	shadow_coord = light_shadow_matrix * vi4;
 
-#if defined(LIGHT_USE_PSSM2) || defined(LIGHT_USE_PSSM4)
+#if defined(LIGHT_USE_PSSM2) || defined(LIGHT_USE_PSSM3) || defined(LIGHT_USE_PSSM4)
 	shadow_coord2 = light_shadow_matrix2 * vi4;
 #endif
 
-#if defined(LIGHT_USE_PSSM4)
+#if defined(LIGHT_USE_PSSM3) || defined(LIGHT_USE_PSSM4)
 	shadow_coord3 = light_shadow_matrix3 * vi4;
-	shadow_coord4 = light_shadow_matrix4 * vi4;
+#endif
 
+#if defined(LIGHT_USE_PSSM4)
+	shadow_coord4 = light_shadow_matrix4 * vi4;
 #endif
 
 #endif //use shadow and use lighting
@@ -1078,15 +1081,19 @@ uniform highp vec4 light_split_offsets;
 
 varying highp vec4 shadow_coord;
 
-#if defined(LIGHT_USE_PSSM2) || defined(LIGHT_USE_PSSM4)
+#if defined(LIGHT_USE_PSSM2) || defined(LIGHT_USE_PSSM3) || defined(LIGHT_USE_PSSM4)
 varying highp vec4 shadow_coord2;
 #endif
 
-#if defined(LIGHT_USE_PSSM4)
+#if defined(LIGHT_USE_PSSM3) || defined(LIGHT_USE_PSSM4)
 
 varying highp vec4 shadow_coord3;
+
+#if defined(LIGHT_USE_PSSM4)
+
 varying highp vec4 shadow_coord4;
 
+#endif
 #endif
 
 uniform vec4 light_clamp;
@@ -2006,6 +2013,55 @@ FRAGMENT_SHADER_CODE
 
 #endif //LIGHT_USE_PSSM4
 
+#ifdef LIGHT_USE_PSSM3
+	//take advantage of prefetch
+	float shadow1 = sample_shadow(light_directional_shadow, shadow_coord);
+	float shadow2 = sample_shadow(light_directional_shadow, shadow_coord2);
+	float shadow3 = sample_shadow(light_directional_shadow, shadow_coord3);
+
+	if (depth_z < light_split_offsets.z) {
+		float pssm_fade = 0.0;
+		float shadow_att = 1.0;
+#ifdef LIGHT_USE_PSSM_BLEND
+		float shadow_att2 = 1.0;
+		float pssm_blend = 0.0;
+		bool use_blend = true;
+#endif
+		if (depth_z < light_split_offsets.y) {
+			if (depth_z < light_split_offsets.x) {
+				shadow_att = shadow1;
+
+#ifdef LIGHT_USE_PSSM_BLEND
+				shadow_att2 = shadow2;
+
+				pssm_blend = smoothstep(0.0, light_split_offsets.x, depth_z);
+#endif
+			} else {
+				shadow_att = shadow2;
+
+#ifdef LIGHT_USE_PSSM_BLEND
+				shadow_att2 = shadow3;
+
+				pssm_blend = smoothstep(light_split_offsets.x, light_split_offsets.y, depth_z);
+#endif
+			}
+		} else {
+			shadow_att = shadow3;
+
+#if defined(LIGHT_USE_PSSM_BLEND)
+			use_blend = false;
+#endif
+		}
+#if defined(LIGHT_USE_PSSM_BLEND)
+		if (use_blend) {
+			shadow_att = mix(shadow_att, shadow_att2, pssm_blend);
+		}
+#endif
+		light_att *= mix(shadow_color.rgb, vec3(1.0), shadow_att);
+	}
+
+#endif //LIGHT_USE_PSSM3
+
 #ifdef LIGHT_USE_PSSM2
 
 	//take advantage of prefetch
@@ -2046,7 +2102,7 @@ FRAGMENT_SHADER_CODE
 
 #endif //LIGHT_USE_PSSM2
 
-#if !defined(LIGHT_USE_PSSM4) && !defined(LIGHT_USE_PSSM2)
+#if !defined(LIGHT_USE_PSSM4) && !defined(LIGHT_USE_PSSM3) && !defined(LIGHT_USE_PSSM2)
 
 	light_att *= mix(shadow_color.rgb, vec3(1.0), sample_shadow(light_directional_shadow, shadow_coord));
 #endif //orthogonal
@@ -2056,6 +2112,8 @@ FRAGMENT_SHADER_CODE
 	{
 #ifdef LIGHT_USE_PSSM4
 		if (depth_z < light_split_offsets.w) {
+#elif defined(LIGHT_USE_PSSM3)
+		if (depth_z < light_split_offsets.z) {
 #elif defined(LIGHT_USE_PSSM2)
 		if (depth_z < light_split_offsets.y) {
 #else
@@ -2112,6 +2170,35 @@ FRAGMENT_SHADER_CODE
 
 #endif // LIGHT_USE_PSSM4
 
+#ifdef LIGHT_USE_PSSM3
+
+			if (depth_z < light_split_offsets.y) {
+				if (depth_z < light_split_offsets.x) {
+					pssm_coord = shadow_coord;
+
+#ifdef LIGHT_USE_PSSM_BLEND
+					pssm_coord2 = shadow_coord2;
+					pssm_blend = smoothstep(0.0, light_split_offsets.x, depth_z);
+#endif
+				} else {
+					pssm_coord = shadow_coord2;
+
+#ifdef LIGHT_USE_PSSM_BLEND
+					pssm_coord2 = shadow_coord3;
+					pssm_blend = smoothstep(light_split_offsets.x, light_split_offsets.y, depth_z);
+#endif
+				}
+			} else {
+				pssm_coord = shadow_coord3;
+				pssm_fade = smoothstep(light_split_offsets.y, light_split_offsets.z, depth_z);
+
+#if defined(LIGHT_USE_PSSM_BLEND)
+				use_blend = false;
+#endif
+			}
+
+#endif // LIGHT_USE_PSSM3
+
 #ifdef LIGHT_USE_PSSM2
 			if (depth_z < light_split_offsets.x) {
 				pssm_coord = shadow_coord;
@@ -2130,7 +2217,7 @@ FRAGMENT_SHADER_CODE
 
 #endif // LIGHT_USE_PSSM2
 
-#if !defined(LIGHT_USE_PSSM4) && !defined(LIGHT_USE_PSSM2)
+#if !defined(LIGHT_USE_PSSM4) && !defined(LIGHT_USE_PSSM3) && !defined(LIGHT_USE_PSSM2)
 			{
 				pssm_coord = shadow_coord;
 			}

drivers/gles3/rasterizer_scene_gles3.cpp

@@ -463,6 +463,7 @@ int RasterizerSceneGLES3::get_directional_light_shadow_size(RID p_light_intance)
 		case VS::LIGHT_DIRECTIONAL_SHADOW_ORTHOGONAL:
 			break; //none
 		case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_2_SPLITS:
+		case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS:
 		case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS:
 			shadow_size /= 2;
 			break;
@@ -2040,9 +2041,9 @@ void RasterizerSceneGLES3::_render_list(RenderList::Element **p_elements, int p_
 					state.scene_shader.set_conditional(SceneShaderGLES3::USE_LIGHT_DIRECTIONAL, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_DIRECTIONAL_SHADOW, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM4, false);
+					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM3, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM2, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM_BLEND, false);
-					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM_BLEND, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::SHADOW_MODE_PCF_5, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::SHADOW_MODE_PCF_13, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::USE_GI_PROBES, false);
@@ -2067,6 +2068,7 @@ void RasterizerSceneGLES3::_render_list(RenderList::Element **p_elements, int p_
 					state.scene_shader.set_conditional(SceneShaderGLES3::USE_LIGHT_DIRECTIONAL, use_directional);
 					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_DIRECTIONAL_SHADOW, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM4, false);
+					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM3, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM2, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM_BLEND, false);
 					state.scene_shader.set_conditional(SceneShaderGLES3::SHADOW_MODE_PCF_5, shadow_filter_mode == SHADOW_FILTER_PCF5);
@@ -2085,6 +2087,10 @@ void RasterizerSceneGLES3::_render_list(RenderList::Element **p_elements, int p_
 									state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM2, true);
 									state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM_BLEND, directional_light->light_ptr->directional_blend_splits);
 									break;
+								case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS:
+									state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM3, true);
+									state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM_BLEND, directional_light->light_ptr->directional_blend_splits);
+									break;
 								case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS:
 									state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM4, true);
 									state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM_BLEND, directional_light->light_ptr->directional_blend_splits);
@@ -2227,6 +2233,7 @@ void RasterizerSceneGLES3::_render_list(RenderList::Element **p_elements, int p_
 	state.scene_shader.set_conditional(SceneShaderGLES3::USE_LIGHT_DIRECTIONAL, false);
 	state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_DIRECTIONAL_SHADOW, false);
 	state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM4, false);
+	state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM3, false);
 	state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM2, false);
 	state.scene_shader.set_conditional(SceneShaderGLES3::LIGHT_USE_PSSM_BLEND, false);
 	state.scene_shader.set_conditional(SceneShaderGLES3::SHADELESS, false);
@@ -2724,6 +2731,9 @@ void RasterizerSceneGLES3::_setup_directional_light(int p_index, const Transform
 			case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_2_SPLITS: {
 				shadow_count = 2;
 			} break;
+			case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS: {
+				shadow_count = 3;
+			} break;
 			case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS: {
 				shadow_count = 4;
 			} break;
@@ -2735,7 +2745,7 @@ void RasterizerSceneGLES3::_setup_directional_light(int p_index, const Transform
 			uint32_t width = li->directional_rect.size.x;
 			uint32_t height = li->directional_rect.size.y;
 
-			if (li->light_ptr->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS) {
+			if (li->light_ptr->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS || li->light_ptr->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS) {
 				width /= 2;
 				height /= 2;
 
@@ -4742,7 +4752,7 @@ void RasterizerSceneGLES3::render_shadow(RID p_light, RID p_shadow_atlas, int p_
 		width = light_instance->directional_rect.size.x;
 		height = light_instance->directional_rect.size.y;
 
-		if (light->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS) {
+		if (light->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS || light->directional_shadow_mode == VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS) {
 			width /= 2;
 			height /= 2;
 

drivers/gles3/shaders/scene.glsl

@@ -2129,11 +2129,15 @@ FRAGMENT_SHADER_CODE
 #ifdef LIGHT_USE_PSSM4 //ubershader-runtime
 	value = shadow_split_offsets.w;
 #else //ubershader-runtime
+#ifdef LIGHT_USE_PSSM3 //ubershader-runtime
+	value = shadow_split_offsets.z;
+#else //ubershader-runtime
 #ifdef LIGHT_USE_PSSM2 //ubershader-runtime
 	value = shadow_split_offsets.y;
 #else //ubershader-runtime
 	value = shadow_split_offsets.x;
 #endif //ubershader-runtime
+#endif //ubershader-runtime
 #endif //LIGHT_USE_PSSM4 //ubershader-runtime
 	if (depth_z < value) {
 		vec3 pssm_coord;
@@ -2194,6 +2198,42 @@ FRAGMENT_SHADER_CODE
 
 #endif //LIGHT_USE_PSSM4 //ubershader-runtime
 
+#ifdef LIGHT_USE_PSSM3 //ubershader-runtime
+
+		if (depth_z < shadow_split_offsets.y) {
+			if (depth_z < shadow_split_offsets.x) {
+				highp vec4 splane = (shadow_matrix1 * vec4(vertex, 1.0));
+				pssm_coord = splane.xyz / splane.w;
+
+#ifdef LIGHT_USE_PSSM_BLEND //ubershader-runtime
+
+				splane = (shadow_matrix2 * vec4(vertex, 1.0));
+				pssm_coord2 = splane.xyz / splane.w;
+				pssm_blend = smoothstep(0.0, shadow_split_offsets.x, depth_z);
+#endif //ubershader-runtime
+
+			} else {
+				highp vec4 splane = (shadow_matrix2 * vec4(vertex, 1.0));
+				pssm_coord = splane.xyz / splane.w;
+
+#ifdef LIGHT_USE_PSSM_BLEND //ubershader-runtime
+				splane = (shadow_matrix3 * vec4(vertex, 1.0));
+				pssm_coord2 = splane.xyz / splane.w;
+				pssm_blend = smoothstep(shadow_split_offsets.x, shadow_split_offsets.y, depth_z);
+#endif //ubershader-runtime
+			}
+		} else {
+			highp vec4 splane = (shadow_matrix3 * vec4(vertex, 1.0));
+			pssm_coord = splane.xyz / splane.w;
+			pssm_fade = smoothstep(shadow_split_offsets.y, shadow_split_offsets.z, depth_z);
+
+#ifdef LIGHT_USE_PSSM_BLEND //ubershader-runtime
+			use_blend = false;
+#endif //ubershader-runtime
+		}
+
+#endif //LIGHT_USE_PSSM3 //ubershader-runtime
+
 #ifdef LIGHT_USE_PSSM2 //ubershader-runtime
 
 		if (depth_z < shadow_split_offsets.x) {
@@ -2220,12 +2260,14 @@ FRAGMENT_SHADER_CODE
 #endif //LIGHT_USE_PSSM2 //ubershader-runtime
 
 #ifndef LIGHT_USE_PSSM2 //ubershader-runtime
+#ifndef LIGHT_USE_PSSM3 //ubershader-runtime
 #ifndef LIGHT_USE_PSSM4 //ubershader-runtime
 		{ //regular orthogonal
 			highp vec4 splane = (shadow_matrix1 * vec4(vertex, 1.0));
 			pssm_coord = splane.xyz / splane.w;
 		}
 #endif //ubershader-runtime
+#endif //ubershader-runtime
 #endif //ubershader-runtime
 
 		//one one sample

scene/3d/light.cpp

@@ -386,7 +386,7 @@ void DirectionalLight::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("is_blend_splits_enabled"), &DirectionalLight::is_blend_splits_enabled);
 
 	ADD_GROUP("Directional Shadow", "directional_shadow_");
-	ADD_PROPERTY(PropertyInfo(Variant::INT, "directional_shadow_mode", PROPERTY_HINT_ENUM, "Orthogonal (Fast),PSSM 2 Splits (Average),PSSM 4 Splits (Slow)"), "set_shadow_mode", "get_shadow_mode");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "directional_shadow_mode", PROPERTY_HINT_ENUM, "Orthogonal (Fast),PSSM 2 Splits (Average),PSSM 3 Splits (Slow),PSSM 4 Splits (Very Slow)"), "set_shadow_mode", "get_shadow_mode");
 	ADD_PROPERTYI(PropertyInfo(Variant::REAL, "directional_shadow_split_1", PROPERTY_HINT_RANGE, "0,1,0.001"), "set_param", "get_param", PARAM_SHADOW_SPLIT_1_OFFSET);
 	ADD_PROPERTYI(PropertyInfo(Variant::REAL, "directional_shadow_split_2", PROPERTY_HINT_RANGE, "0,1,0.001"), "set_param", "get_param", PARAM_SHADOW_SPLIT_2_OFFSET);
 	ADD_PROPERTYI(PropertyInfo(Variant::REAL, "directional_shadow_split_3", PROPERTY_HINT_RANGE, "0,1,0.001"), "set_param", "get_param", PARAM_SHADOW_SPLIT_3_OFFSET);
@@ -398,6 +398,7 @@ void DirectionalLight::_bind_methods() {
 
 	BIND_ENUM_CONSTANT(SHADOW_ORTHOGONAL);
 	BIND_ENUM_CONSTANT(SHADOW_PARALLEL_2_SPLITS);
+	BIND_ENUM_CONSTANT(SHADOW_PARALLEL_3_SPLITS);
 	BIND_ENUM_CONSTANT(SHADOW_PARALLEL_4_SPLITS);
 
 	BIND_ENUM_CONSTANT(SHADOW_DEPTH_RANGE_STABLE);

scene/3d/light.h

@@ -139,6 +139,7 @@ public:
 	enum ShadowMode {
 		SHADOW_ORTHOGONAL,
 		SHADOW_PARALLEL_2_SPLITS,
+		SHADOW_PARALLEL_3_SPLITS,
 		SHADOW_PARALLEL_4_SPLITS
 	};
 

servers/visual/visual_server_scene.cpp

@@ -2514,6 +2514,9 @@ bool VisualServerScene::_light_instance_update_shadow(Instance *p_instance, cons
 				case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_2_SPLITS:
 					splits = 2;
 					break;
+				case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS:
+					splits = 3;
+					break;
 				case VS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS:
 					splits = 4;
 					break;

servers/visual_server.cpp

@@ -2383,6 +2383,7 @@ void VisualServer::_bind_methods() {
 
 	BIND_ENUM_CONSTANT(LIGHT_DIRECTIONAL_SHADOW_ORTHOGONAL);
 	BIND_ENUM_CONSTANT(LIGHT_DIRECTIONAL_SHADOW_PARALLEL_2_SPLITS);
+	BIND_ENUM_CONSTANT(LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS);
 	BIND_ENUM_CONSTANT(LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS);
 	BIND_ENUM_CONSTANT(LIGHT_DIRECTIONAL_SHADOW_DEPTH_RANGE_STABLE);
 	BIND_ENUM_CONSTANT(LIGHT_DIRECTIONAL_SHADOW_DEPTH_RANGE_OPTIMIZED);

servers/visual_server.h

@@ -494,6 +494,7 @@ public:
 	enum LightDirectionalShadowMode {
 		LIGHT_DIRECTIONAL_SHADOW_ORTHOGONAL,
 		LIGHT_DIRECTIONAL_SHADOW_PARALLEL_2_SPLITS,
+		LIGHT_DIRECTIONAL_SHADOW_PARALLEL_3_SPLITS,
 		LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS
 	};