Subsurf: Introduce quality option

For users it defines how accurate vertex positions are in terms
of limit surface (as in, how close the vertices locations to the
condition when they are calculated for an infinitely subdivided
mesh).

This affects things like:

- Irregular vertices (joint of 3 or more edges)
- Crease

Keep quality value low for performance.

NOTE: Going higher does not necessarily mean real improvement
in quality, ideal case might be reached well before maximum
quality of 10. Quality of 3 is a good starting point.

Internally quality is translated directly to adaptive subdivision
level.

Reviewers: brecht

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D3599

CMakeLists.txt

@@ -237,6 +237,9 @@ option(WITH_COMPOSITOR         "Enable the tile based nodal compositor" ON)
 
 option(WITH_OPENSUBDIV    "Enable OpenSubdiv for surface subdivision" _init_OPENSUBDIV)
 
+option(WITH_OPENSUBDIV_MODIFIER    "Use OpenSubdiv for CPU side of Subsurf/Multires modifiers" OFF)
+mark_as_advanced(WITH_OPENSUBDIV_MODIFIER)
+
 option(WITH_OPENVDB       "Enable features relying on OpenVDB" OFF)
 option(WITH_OPENVDB_BLOSC "Enable blosc compression for OpenVDB, only enable if OpenVDB was built with blosc support" OFF)
 option(WITH_OPENVDB_3_ABI_COMPATIBLE "Assume OpenVDB library has been compiled with version 3 ABI compatibility" OFF)

release/scripts/startup/bl_ui/properties_data_modifier.py

@@ -986,6 +986,8 @@ class DATA_PT_modifiers(ModifierButtonsPanel, Panel):
             col.label(text="Subdivisions:")
             col.prop(md, "levels", text="View")
             col.prop(md, "render_levels", text="Render")
+            if hasattr(md, "quality"):
+                col.prop(md, "quality")
 
         col = split.column()
         col.label(text="Options:")

source/blender/blenkernel/intern/multires.c

@@ -728,6 +728,7 @@ static DerivedMesh *subsurf_dm_create_local(
 	SubsurfFlags flags = 0;
 
 	smd.levels = smd.renderLevels = lvl;
+	smd.quality = 3;
 	if (!is_plain_uv) {
 		smd.uv_smooth = SUBSURF_UV_SMOOTH_PRESERVE_CORNERS;
 	}

source/blender/blenloader/intern/versioning_280.c

@@ -1855,5 +1855,16 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
 				}
 			}
 		}
+
+		if (!DNA_struct_elem_find(fd->filesdna, "SubsurfModifier", "short", "quality")) {
+			for (Object *object = bmain->object.first; object != NULL; object = object->id.next) {
+				for (ModifierData *md = object->modifiers.first; md; md = md->next) {
+					if (md->type == eModifierType_Subsurf) {
+						SubsurfModifierData *smd = (SubsurfModifierData *)md;
+						smd->quality = 3;
+					}
+				}
+			}
+		}
 	}
 }

source/blender/makesdna/DNA_modifier_types.h

@@ -162,7 +162,8 @@ typedef struct SubsurfModifierData {
 
 	short subdivType, levels, renderLevels, flags;
 	short uv_smooth;
-	short pad[3];
+	short quality;
+	short pad[2];
 
 	void *emCache, *mCache;
 } SubsurfModifierData;

source/blender/makesrna/intern/CMakeLists.txt

@@ -305,6 +305,10 @@ if(WITH_OPENSUBDIV)
 	add_definitions(-DWITH_OPENSUBDIV)
 endif()
 
+if(WITH_OPENSUBDIV_MODIFIER)
+	add_definitions(-DWITH_OPENSUBDIV_MODIFIER)
+endif()
+
 if(WITH_OPENVDB)
 	add_definitions(-DWITH_OPENVDB)
 

source/blender/makesrna/intern/rna_modifier.c

@@ -1249,6 +1249,15 @@ static void rna_def_modifier_subsurf(BlenderRNA *brna)
 	RNA_def_property_enum_items(prop, prop_uv_smooth_items);
 	RNA_def_property_ui_text(prop, "UV Smooth", "Controls how smoothing is applied to UVs");
 	RNA_def_property_update(prop, 0, "rna_Modifier_update");
+
+#ifdef WITH_OPENSUBDIV_MODIFIER
+	prop = RNA_def_property(srna, "quality", PROP_INT, PROP_UNSIGNED);
+	RNA_def_property_int_sdna(prop, NULL, "quality");
+	RNA_def_property_range(prop, 1, 10);
+	RNA_def_property_ui_range(prop, 1, 6, 1, -1);
+	RNA_def_property_ui_text(prop, "Quality", "Accuracy of vertex positions, lower value is faster but less precise");
+	RNA_def_property_update(prop, 0, "rna_Modifier_update");
+#endif
 }
 
 static void rna_def_modifier_generic_map_info(StructRNA *srna)

source/blender/modifiers/CMakeLists.txt

@@ -144,8 +144,8 @@ if(WITH_INTERNATIONAL)
 	add_definitions(-DWITH_INTERNATIONAL)
 endif()
 
-if(WITH_OPENSUBDIV)
+if(WITH_OPENSUBDIV_MODIFIER)
-	add_definitions(-DWITH_OPENSUBDIV)
+	add_definitions(-DWITH_OPENSUBDIV_MODIFIER)
 endif()
 
 # So we can have special tricks in modifier system.

source/blender/modifiers/intern/MOD_subsurf.c

@@ -39,10 +39,6 @@
 #include "DNA_scene_types.h"
 #include "DNA_mesh_types.h"
 
-#ifdef WITH_OPENSUBDIV
-#  include "DNA_userdef_types.h"
-#endif
-
 #include "BLI_utildefines.h"
 
 #include "BKE_cdderivedmesh.h"
@@ -57,8 +53,6 @@
 
 #include "intern/CCGSubSurf.h"
 
-// #define USE_OPENSUBDIV
-
 static void initData(ModifierData *md)
 {
 	SubsurfModifierData *smd = (SubsurfModifierData *) md;
@@ -66,6 +60,7 @@ static void initData(ModifierData *md)
 	smd->levels = 1;
 	smd->renderLevels = 2;
 	smd->uv_smooth = SUBSURF_UV_SMOOTH_PRESERVE_CORNERS;
+	smd->quality = 3;
 }
 
 static void copyData(const ModifierData *md, ModifierData *target, const int flag)
@@ -151,26 +146,25 @@ static DerivedMesh *applyModifierEM(
 	return result;
 }
 
-#ifdef USE_OPENSUBDIV
+#ifdef WITH_OPENSUBDIV_MODIFIER
 static int subdiv_levels_for_modifier_get(const SubsurfModifierData *smd,
                                           const ModifierEvalContext *ctx)
 {
-	Scene *scene = DEG_get_evaluated_scene(ctx->depsgraph);
+       Scene *scene = DEG_get_evaluated_scene(ctx->depsgraph);
-	const bool use_render_params = (ctx->flag & MOD_APPLY_RENDER);
+       const bool use_render_params = (ctx->flag & MOD_APPLY_RENDER);
-	const int requested_levels = (use_render_params) ? smd->renderLevels
+       const int requested_levels = (use_render_params) ? smd->renderLevels
-	                                                 : smd->levels;
+                                                        : smd->levels;
-	return get_render_subsurf_level(&scene->r,
+       return get_render_subsurf_level(&scene->r,
-	                                requested_levels,
+                                       requested_levels,
-	                                use_render_params);
+                                       use_render_params);
 }
 
 static void subdiv_settings_init(SubdivSettings *settings,
-                                 const SubsurfModifierData *smd,
+                                 const SubsurfModifierData *smd)
-                                 const ModifierEvalContext *ctx)
 {
 	settings->is_simple = (smd->subdivType == SUBSURF_TYPE_SIMPLE);
 	settings->is_adaptive = !settings->is_simple;
-	settings->level = subdiv_levels_for_modifier_get(smd, ctx);
+	settings->level = smd->quality;
 	switch (smd->uv_smooth) {
 		case SUBSURF_UV_SMOOTH_NONE:
 			settings->fvar_linear_interpolation =
@@ -200,9 +194,11 @@ static void subdiv_settings_init(SubdivSettings *settings,
 }
 
 static void subdiv_mesh_settings_init(SubdivToMeshSettings *settings,
-                                      const SubdivSettings *subdiv_settings)
+                                      const SubsurfModifierData *smd,
+                                      const ModifierEvalContext *ctx)
 {
-	settings->resolution = (1 << subdiv_settings->level) + 1;
+	const int level = subdiv_levels_for_modifier_get(smd, ctx);
+	settings->resolution = (1 << level) + 1;
 }
 
 static Mesh *applyModifier_subdiv(ModifierData *md,
@@ -212,7 +208,7 @@ static Mesh *applyModifier_subdiv(ModifierData *md,
 	Mesh *result = mesh;
 	SubsurfModifierData *smd = (SubsurfModifierData *) md;
 	SubdivSettings subdiv_settings;
-	subdiv_settings_init(&subdiv_settings, smd, ctx);
+	subdiv_settings_init(&subdiv_settings, smd);
 	if (subdiv_settings.level == 0) {
 		/* NOTE: Shouldn't really happen, is supposed to be catched by
 		 * isDisabled() callback.
@@ -226,7 +222,7 @@ static Mesh *applyModifier_subdiv(ModifierData *md,
 		return result;
 	}
 	SubdivToMeshSettings mesh_settings;
-	subdiv_mesh_settings_init(&mesh_settings, &subdiv_settings);
+	subdiv_mesh_settings_init(&mesh_settings, smd, ctx);
 	result = BKE_subdiv_to_mesh(subdiv, &mesh_settings, mesh);
 	/* TODO(sergey): Cache subdiv somehow. */
 	// BKE_subdiv_stats_print(&subdiv->stats);
@@ -259,7 +255,7 @@ ModifierTypeInfo modifierType_Subsurf = {
 	/* deformMatrices */    NULL,
 	/* deformVertsEM */     NULL,
 	/* deformMatricesEM */  NULL,
-#ifdef USE_OPENSUBDIV
+#ifdef WITH_OPENSUBDIV_MODIFIER
 	/* applyModifier */     applyModifier_subdiv,
 #else
 	/* applyModifier */     NULL,

source/blender/render/intern/source/multires_bake.c

@@ -684,6 +684,7 @@ static void *init_heights_data(MultiresBakeRender *bkr, Image *ima)
 		if (ss_lvl > 0) {
 			smd.levels = smd.renderLevels = ss_lvl;
 			smd.uv_smooth = SUBSURF_UV_SMOOTH_PRESERVE_CORNERS;
+			smd.quality = 3;
 
 			if (bkr->simple)
 				smd.subdivType = ME_SIMPLE_SUBSURF;