Merge pull request #82668 from mrjustaguy/master

Improve split blending logic for Vulkan

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

@@ -1860,7 +1860,7 @@ void fragment_shader(in SceneData scene_data) {
 
 					pssm_coord /= pssm_coord.w;
 
-					shadow = sample_directional_pcf_shadow(directional_shadow_atlas, scene_data.directional_shadow_pixel_size * directional_lights.data[i].soft_shadow_scale * blur_factor, pssm_coord);
+					shadow = sample_directional_pcf_shadow(directional_shadow_atlas, scene_data.directional_shadow_pixel_size * directional_lights.data[i].soft_shadow_scale * (blur_factor + (1.0 - blur_factor) * float(directional_lights.data[i].blend_splits)), pssm_coord);
 
 					if (directional_lights.data[i].blend_splits) {
 						float pssm_blend;
@@ -1870,21 +1870,21 @@ void fragment_shader(in SceneData scene_data) {
 							vec4 v = vec4(vertex, 1.0);
 							BIAS_FUNC(v, 1)
 							pssm_coord = (directional_lights.data[i].shadow_matrix2 * v);
-							pssm_blend = smoothstep(0.0, directional_lights.data[i].shadow_split_offsets.x, depth_z);
+							pssm_blend = smoothstep(directional_lights.data[i].shadow_split_offsets.x - directional_lights.data[i].shadow_split_offsets.x * 0.1, directional_lights.data[i].shadow_split_offsets.x, depth_z);
 							// Adjust shadow blur with reference to the first split to reduce discrepancy between shadow splits.
 							blur_factor2 = directional_lights.data[i].shadow_split_offsets.x / directional_lights.data[i].shadow_split_offsets.y;
 						} else if (depth_z < directional_lights.data[i].shadow_split_offsets.y) {
 							vec4 v = vec4(vertex, 1.0);
 							BIAS_FUNC(v, 2)
 							pssm_coord = (directional_lights.data[i].shadow_matrix3 * v);
-							pssm_blend = smoothstep(directional_lights.data[i].shadow_split_offsets.x, directional_lights.data[i].shadow_split_offsets.y, depth_z);
+							pssm_blend = smoothstep(directional_lights.data[i].shadow_split_offsets.y - directional_lights.data[i].shadow_split_offsets.y * 0.1, directional_lights.data[i].shadow_split_offsets.y, depth_z);
 							// Adjust shadow blur with reference to the first split to reduce discrepancy between shadow splits.
 							blur_factor2 = directional_lights.data[i].shadow_split_offsets.x / directional_lights.data[i].shadow_split_offsets.z;
 						} else if (depth_z < directional_lights.data[i].shadow_split_offsets.z) {
 							vec4 v = vec4(vertex, 1.0);
 							BIAS_FUNC(v, 3)
 							pssm_coord = (directional_lights.data[i].shadow_matrix4 * v);
-							pssm_blend = smoothstep(directional_lights.data[i].shadow_split_offsets.y, directional_lights.data[i].shadow_split_offsets.z, depth_z);
+							pssm_blend = smoothstep(directional_lights.data[i].shadow_split_offsets.z - directional_lights.data[i].shadow_split_offsets.z * 0.1, directional_lights.data[i].shadow_split_offsets.z, depth_z);
 							// Adjust shadow blur with reference to the first split to reduce discrepancy between shadow splits.
 							blur_factor2 = directional_lights.data[i].shadow_split_offsets.x / directional_lights.data[i].shadow_split_offsets.w;
 						} else {
@@ -1894,7 +1894,7 @@ void fragment_shader(in SceneData scene_data) {
 
 						pssm_coord /= pssm_coord.w;
 
-						float shadow2 = sample_directional_pcf_shadow(directional_shadow_atlas, scene_data.directional_shadow_pixel_size * directional_lights.data[i].soft_shadow_scale * blur_factor2, pssm_coord);
+						float shadow2 = sample_directional_pcf_shadow(directional_shadow_atlas, scene_data.directional_shadow_pixel_size * directional_lights.data[i].soft_shadow_scale * (blur_factor2 + (1.0 - blur_factor2) * float(directional_lights.data[i].blend_splits)), pssm_coord);
 						shadow = mix(shadow, shadow2, pssm_blend);
 					}
 				}

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

@@ -1506,7 +1506,7 @@ void main() {
 
 				pssm_coord /= pssm_coord.w;
 
-				shadow = sample_directional_pcf_shadow(directional_shadow_atlas, scene_data.directional_shadow_pixel_size * directional_lights.data[i].soft_shadow_scale * blur_factor, pssm_coord);
+				shadow = sample_directional_pcf_shadow(directional_shadow_atlas, scene_data.directional_shadow_pixel_size * directional_lights.data[i].soft_shadow_scale * (blur_factor + (1.0 - blur_factor) * float(directional_lights.data[i].blend_splits)), pssm_coord);
 
 				if (directional_lights.data[i].blend_splits) {
 					float pssm_blend;
@@ -1516,21 +1516,21 @@ void main() {
 						vec4 v = vec4(vertex, 1.0);
 						BIAS_FUNC(v, 1)
 						pssm_coord = (directional_lights.data[i].shadow_matrix2 * v);
-						pssm_blend = smoothstep(0.0, directional_lights.data[i].shadow_split_offsets.x, depth_z);
+						pssm_blend = smoothstep(directional_lights.data[i].shadow_split_offsets.x - directional_lights.data[i].shadow_split_offsets.x * 0.1, directional_lights.data[i].shadow_split_offsets.x, depth_z);
 						// Adjust shadow blur with reference to the first split to reduce discrepancy between shadow splits.
 						blur_factor2 = directional_lights.data[i].shadow_split_offsets.x / directional_lights.data[i].shadow_split_offsets.y;
 					} else if (depth_z < directional_lights.data[i].shadow_split_offsets.y) {
 						vec4 v = vec4(vertex, 1.0);
 						BIAS_FUNC(v, 2)
 						pssm_coord = (directional_lights.data[i].shadow_matrix3 * v);
-						pssm_blend = smoothstep(directional_lights.data[i].shadow_split_offsets.x, directional_lights.data[i].shadow_split_offsets.y, depth_z);
+						pssm_blend = smoothstep(directional_lights.data[i].shadow_split_offsets.y - directional_lights.data[i].shadow_split_offsets.y * 0.1, directional_lights.data[i].shadow_split_offsets.y, depth_z);
 						// Adjust shadow blur with reference to the first split to reduce discrepancy between shadow splits.
 						blur_factor2 = directional_lights.data[i].shadow_split_offsets.x / directional_lights.data[i].shadow_split_offsets.z;
 					} else if (depth_z < directional_lights.data[i].shadow_split_offsets.z) {
 						vec4 v = vec4(vertex, 1.0);
 						BIAS_FUNC(v, 3)
 						pssm_coord = (directional_lights.data[i].shadow_matrix4 * v);
-						pssm_blend = smoothstep(directional_lights.data[i].shadow_split_offsets.y, directional_lights.data[i].shadow_split_offsets.z, depth_z);
+						pssm_blend = smoothstep(directional_lights.data[i].shadow_split_offsets.z - directional_lights.data[i].shadow_split_offsets.z * 0.1, directional_lights.data[i].shadow_split_offsets.z, depth_z);
 						// Adjust shadow blur with reference to the first split to reduce discrepancy between shadow splits.
 						blur_factor2 = directional_lights.data[i].shadow_split_offsets.x / directional_lights.data[i].shadow_split_offsets.w;
 					} else {
@@ -1540,7 +1540,7 @@ void main() {
 
 					pssm_coord /= pssm_coord.w;
 
-					float shadow2 = sample_directional_pcf_shadow(directional_shadow_atlas, scene_data.directional_shadow_pixel_size * directional_lights.data[i].soft_shadow_scale * blur_factor2, pssm_coord);
+					float shadow2 = sample_directional_pcf_shadow(directional_shadow_atlas, scene_data.directional_shadow_pixel_size * directional_lights.data[i].soft_shadow_scale * (blur_factor2 + (1.0 - blur_factor2) * float(directional_lights.data[i].blend_splits)), pssm_coord);
 					shadow = mix(shadow, shadow2, pssm_blend);
 				}