Workbench: Add Shadow Focus and change Shadow Orientation

Shadow focus let the user choose how hard are is the shadows transition.
Harder shadow transition can be used for stylistic effects or more uniform
shading.

Make shadow orientation respect the same orientation as the studio light
(view from +Y direction aka. front view). Make the default shadow direction
more similar to the default light position (the default light object, not
the default studio lighting).

8 files changed, 39 insertions, 10 deletions

diff --git a/source/blender/blenkernel/intern/scene.c b/source/blender/blenkernel/intern/scene.c
index 090c016ed00..7a6f1ec85b4 100644
--- a/source/blender/blenkernel/intern/scene.c
+++ b/source/blender/blenkernel/intern/scene.c
@@ -858,8 +858,9 @@ void BKE_scene_init(Scene *sce)
 	BKE_view_layer_add(sce, "View Layer");
 
 	/* SceneDisplay */
-	copy_v3_v3(sce->display.light_direction, (float[3]){-M_SQRT1_3, -M_SQRT1_3, M_SQRT1_3});
-	sce->display.shadow_shift = 0.1;
+	copy_v3_v3(sce->display.light_direction, (float[3]){M_SQRT1_3, M_SQRT1_3, M_SQRT1_3});
+	sce->display.shadow_shift = 0.1f;
+	sce->display.shadow_focus = 0.0f;
 
 	sce->display.matcap_ssao_distance = 0.2f;
 	sce->display.matcap_ssao_attenuation = 1.0f;
diff --git a/source/blender/blenloader/intern/versioning_280.c b/source/blender/blenloader/intern/versioning_280.c
index 434153fc7b9..17859d257d0 100644
--- a/source/blender/blenloader/intern/versioning_280.c
+++ b/source/blender/blenloader/intern/versioning_280.c
@@ -2480,5 +2480,15 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
 				}
 			}
 		}
+
+		/* Change Solid mode shadow orientation. */
+		if (!DNA_struct_elem_find(fd->filesdna, "SceneDisplay", "float", "shadow_focus")) {
+			for (Scene *scene = bmain->scene.first; scene; scene = scene->id.next) {
+				float *dir = scene->display.light_direction;
+				SWAP(float, dir[2], dir[1]);
+				dir[2] = -dir[2];
+				dir[0] = -dir[0];
+			}
+		}
 	}
 }
diff --git a/source/blender/blenloader/intern/versioning_defaults.c b/source/blender/blenloader/intern/versioning_defaults.c
index b88618bf7db..25946a9fb31 100644
--- a/source/blender/blenloader/intern/versioning_defaults.c
+++ b/source/blender/blenloader/intern/versioning_defaults.c
@@ -301,4 +301,8 @@ void BLO_update_defaults_startup_blend(Main *bmain, const char *app_template)
 			}
 		}
 	}
+
+	for (Scene *scene = bmain->scene.first; scene; scene = scene->id.next) {
+		copy_v3_v3(scene->display.light_direction, (float[3]){M_SQRT1_3, M_SQRT1_3, M_SQRT1_3});
+	}
 }
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_deferred_composite_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_deferred_composite_frag.glsl
index 310169bdf5d..e383d1b1939 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_deferred_composite_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_deferred_composite_frag.glsl
@@ -16,6 +16,7 @@ uniform vec4 viewvecs[3];
 uniform float shadowMultiplier;
 uniform float lightMultiplier;
 uniform float shadowShift = 0.1;
+uniform float shadowFocus = 1.0;
 
 layout(std140) uniform world_block {
 	WorldData world_data;
@@ -99,7 +100,7 @@ void main()
 	float light_factor = -dot(normal_viewport, world_data.shadow_direction_vs.xyz);
 	/* The step function might be ok for meshes but it's
 	 * clearly not the case for hairs. Do smoothstep in this case. */
-	float shadow_mix = smoothstep(1.0, shadowShift, light_factor);
+	float shadow_mix = smoothstep(shadowFocus, shadowShift, light_factor);
 	shaded_color *= mix(lightMultiplier, shadowMultiplier, shadow_mix);
 #endif
 
diff --git a/source/blender/draw/engines/workbench/workbench_data.c b/source/blender/draw/engines/workbench/workbench_data.c
index 1cdf4c2b443..04e760f1909 100644
--- a/source/blender/draw/engines/workbench/workbench_data.c
+++ b/source/blender/draw/engines/workbench/workbench_data.c
@@ -161,7 +161,9 @@ void workbench_private_data_get_light_direction(WORKBENCH_PrivateData *wpd, floa
 	DRW_viewport_matrix_get(view_matrix, DRW_MAT_VIEW);
 
 	copy_v3_v3(r_light_direction, scene->display.light_direction);
-	negate_v3(r_light_direction);
+	SWAP(float, r_light_direction[2], r_light_direction[1]);
+	r_light_direction[2] = -r_light_direction[2];
+	r_light_direction[0] = -r_light_direction[0];
 
 	/* Shadow direction. */
 	mul_v3_mat3_m4v3(wd->shadow_direction_vs, view_matrix, r_light_direction);
diff --git a/source/blender/draw/engines/workbench/workbench_deferred.c b/source/blender/draw/engines/workbench/workbench_deferred.c
index 1ca76da672a..a77179fa676 100644
--- a/source/blender/draw/engines/workbench/workbench_deferred.c
+++ b/source/blender/draw/engines/workbench/workbench_deferred.c
@@ -566,7 +566,10 @@ void workbench_deferred_cache_init(WORKBENCH_Data *vedata)
 		workbench_private_data_get_light_direction(wpd, e_data.display.light_direction);
 		studiolight_update_light(wpd, e_data.display.light_direction);
 
-		e_data.display.shadow_shift = scene->display.shadow_shift;
+		float shadow_focus = scene->display.shadow_focus;
+		/* Clamp to avoid overshadowing and shading errors. */
+		CLAMP(shadow_focus, 0.0001f, 0.99999f);
+		shadow_focus = 1.0f - shadow_focus * (1.0f - scene->display.shadow_shift);
 
 		if (SHADOW_ENABLED(wpd)) {
 			psl->composite_pass = DRW_pass_create(
@@ -576,7 +579,8 @@ void workbench_deferred_cache_init(WORKBENCH_Data *vedata)
 			DRW_shgroup_stencil_mask(grp, 0x00);
 			DRW_shgroup_uniform_float_copy(grp, "lightMultiplier", 1.0f);
 			DRW_shgroup_uniform_float(grp, "shadowMultiplier", &wpd->shadow_multiplier, 1);
-			DRW_shgroup_uniform_float(grp, "shadowShift", &scene->display.shadow_shift, 1);
+			DRW_shgroup_uniform_float_copy(grp, "shadowShift", scene->display.shadow_shift);
+			DRW_shgroup_uniform_float_copy(grp, "shadowFocus", shadow_focus);
 			DRW_shgroup_call_add(grp, DRW_cache_fullscreen_quad_get(), NULL);
 
 			/* Stencil Shadow passes. */
@@ -614,7 +618,8 @@ void workbench_deferred_cache_init(WORKBENCH_Data *vedata)
 			workbench_composite_uniforms(wpd, grp);
 			DRW_shgroup_uniform_float(grp, "lightMultiplier", &wpd->shadow_multiplier, 1);
 			DRW_shgroup_uniform_float(grp, "shadowMultiplier", &wpd->shadow_multiplier, 1);
-			DRW_shgroup_uniform_float(grp, "shadowShift", &scene->display.shadow_shift, 1);
+			DRW_shgroup_uniform_float_copy(grp, "shadowShift", scene->display.shadow_shift);
+			DRW_shgroup_uniform_float_copy(grp, "shadowFocus", shadow_focus);
 			DRW_shgroup_call_add(grp, DRW_cache_fullscreen_quad_get(), NULL);
 #endif
 
diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index 6cc689378ea..1b31e45b30e 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -1441,13 +1441,12 @@ typedef struct DisplaySafeAreas {
 /* Scene Display - used for store scene specific display settings for the 3d view */
 typedef struct SceneDisplay {
 	float light_direction[3];      /* light direction for shadows/highlight */
-	float shadow_shift;
+	float shadow_shift, shadow_focus;
 
 	/* Settings for Cavity Shader */
 	float matcap_ssao_distance;
 	float matcap_ssao_attenuation;
 	int matcap_ssao_samples;
-	int pad;
 
 	/* OpenGL render engine settings. */
 	View3DShading shading;
diff --git a/source/blender/makesrna/intern/rna_scene.c b/source/blender/makesrna/intern/rna_scene.c
index d6d597aac73..3e3e08459ca 100644
--- a/source/blender/makesrna/intern/rna_scene.c
+++ b/source/blender/makesrna/intern/rna_scene.c
@@ -5591,7 +5591,6 @@ static void rna_def_scene_display(BlenderRNA *brna)
 	RNA_def_property_update(prop, NC_SCENE | NA_EDITED, "rna_Scene_set_update");
 
 	prop = RNA_def_property(srna, "shadow_shift", PROP_FLOAT, PROP_ANGLE);
-	RNA_def_property_float_sdna(prop, NULL, "shadow_shift");
 	RNA_def_property_float_default(prop, 0.1);
 	RNA_def_property_ui_text(prop, "Shadow Shift", "Shadow termination angle");
 	RNA_def_property_range(prop, 0.0f, 1.0f);
@@ -5599,6 +5598,14 @@ static void rna_def_scene_display(BlenderRNA *brna)
 	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
 	RNA_def_property_update(prop, NC_SCENE | NA_EDITED, "rna_Scene_set_update");
 
+	prop = RNA_def_property(srna, "shadow_focus", PROP_FLOAT, PROP_FACTOR);
+	RNA_def_property_float_default(prop, 0.0);
+	RNA_def_property_ui_text(prop, "Shadow Focus", "Shadow factor hardness");
+	RNA_def_property_range(prop, 0.0f, 1.0f);
+	RNA_def_property_ui_range(prop, 0.0f, 1.0f, 1, 2);
+	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
+	RNA_def_property_update(prop, NC_SCENE | NA_EDITED, "rna_Scene_set_update");
+
 	prop = RNA_def_property(srna, "matcap_ssao_distance", PROP_FLOAT, PROP_NONE);
 	RNA_def_property_float_default(prop, 0.2f);
 	RNA_def_property_ui_text(prop, "Distance", "Distance of object that contribute to the Cavity/Edge effect");