Geometry: use generic attributes for Hair and Point Clouds

Instead of custom data layer with special types, using general Vector and Float
attributes.

Ref T76659

Differential Revision: https://developer.blender.org/D8635

source/blender/blenkernel/BKE_attribute.h

@@ -64,6 +64,7 @@ void BKE_id_attribute_remove(struct ID *id,
 
 AttributeDomain BKE_id_attribute_domain(struct ID *id, struct CustomDataLayer *layer);
 int BKE_id_attribute_data_length(struct ID *id, struct CustomDataLayer *layer);
+bool BKE_id_attribute_required(struct ID *id, struct CustomDataLayer *layer);
 bool BKE_id_attribute_rename(struct ID *id,
                              struct CustomDataLayer *layer,
                              const char *new_name,

source/blender/blenkernel/BKE_hair.h

@@ -25,6 +25,7 @@ extern "C" {
 #endif
 
 struct BoundBox;
+struct CustomDataLayer;
 struct Depsgraph;
 struct Hair;
 struct Main;
@@ -37,6 +38,7 @@ struct Hair *BKE_hair_copy(struct Main *bmain, const struct Hair *hair);
 struct BoundBox *BKE_hair_boundbox_get(struct Object *ob);
 
 void BKE_hair_update_customdata_pointers(struct Hair *hair);
+bool BKE_hair_customdata_required(struct Hair *hair, struct CustomDataLayer *layer);
 
 /* Depsgraph */
 

source/blender/blenkernel/BKE_pointcloud.h

@@ -25,6 +25,7 @@ extern "C" {
 #endif
 
 struct BoundBox;
+struct CustomDataLayer;
 struct Depsgraph;
 struct Main;
 struct Object;
@@ -37,6 +38,8 @@ struct PointCloud *BKE_pointcloud_copy(struct Main *bmain, const struct PointClo
 struct BoundBox *BKE_pointcloud_boundbox_get(struct Object *ob);
 
 void BKE_pointcloud_update_customdata_pointers(struct PointCloud *pointcloud);
+bool BKE_pointcloud_customdata_required(struct PointCloud *pointcloud,
+                                        struct CustomDataLayer *layer);
 
 /* Dependency Graph */
 

source/blender/blenkernel/intern/attribute.c

@@ -39,6 +39,8 @@
 
 #include "BKE_attribute.h"
 #include "BKE_customdata.h"
+#include "BKE_hair.h"
+#include "BKE_pointcloud.h"
 #include "BKE_report.h"
 
 #include "RNA_access.h"
@@ -104,6 +106,11 @@ bool BKE_id_attribute_rename(ID *id,
                              const char *new_name,
                              ReportList *reports)
 {
+  if (BKE_id_attribute_required(id, layer)) {
+    BLI_assert(!"Required attribute name is not editable");
+    return false;
+  }
+
   CustomData *customdata = attribute_customdata_find(id, layer);
   if (customdata == NULL) {
     BKE_report(reports, RPT_ERROR, "Attribute is not part of this geometry");
@@ -144,6 +151,11 @@ void BKE_id_attribute_remove(ID *id, CustomDataLayer *layer, ReportList *reports
     return;
   }
 
+  if (BKE_id_attribute_required(id, layer)) {
+    BKE_report(reports, RPT_ERROR, "Attribute is required and can't be removed");
+    return;
+  }
+
   const int length = BKE_id_attribute_data_length(id, layer);
   CustomData_free_layer(customdata, layer->type, length, index);
 }
@@ -197,6 +209,20 @@ int BKE_id_attribute_data_length(ID *id, CustomDataLayer *layer)
   return 0;
 }
 
+bool BKE_id_attribute_required(ID *id, CustomDataLayer *layer)
+{
+  switch (GS(id->name)) {
+    case ID_PT: {
+      return BKE_pointcloud_customdata_required((PointCloud *)id, layer);
+    }
+    case ID_HA: {
+      return BKE_hair_customdata_required((Hair *)id, layer);
+    }
+    default:
+      return false;
+  }
+}
+
 CustomDataLayer *BKE_id_attributes_active_get(ID *id)
 {
   int active_index = *BKE_id_attributes_active_index_p(id);

source/blender/blenkernel/intern/hair.c

@@ -47,6 +47,9 @@
 
 #include "DEG_depsgraph_query.h"
 
+const char *HAIR_ATTR_POSITION = "Position";
+const char *HAIR_ATTR_RADIUS = "Radius";
+
 /* Hair datablock */
 
 static void hair_random(Hair *hair);
@@ -61,8 +64,10 @@ static void hair_init_data(ID *id)
   CustomData_reset(&hair->pdata);
   CustomData_reset(&hair->cdata);
 
-  CustomData_add_layer(&hair->pdata, CD_LOCATION, CD_CALLOC, NULL, hair->totpoint);
-  CustomData_add_layer(&hair->pdata, CD_RADIUS, CD_CALLOC, NULL, hair->totpoint);
+  CustomData_add_layer_named(
+      &hair->pdata, CD_PROP_FLOAT3, CD_CALLOC, NULL, hair->totpoint, HAIR_ATTR_POSITION);
+  CustomData_add_layer_named(
+      &hair->pdata, CD_PROP_FLOAT, CD_CALLOC, NULL, hair->totpoint, HAIR_ATTR_RADIUS);
   CustomData_add_layer(&hair->cdata, CD_HAIRCURVE, CD_CALLOC, NULL, hair->totcurve);
   BKE_hair_update_customdata_pointers(hair);
 
@@ -222,12 +227,17 @@ BoundBox *BKE_hair_boundbox_get(Object *ob)
 
 void BKE_hair_update_customdata_pointers(Hair *hair)
 {
-  hair->co = CustomData_get_layer(&hair->pdata, CD_LOCATION);
-  hair->radius = CustomData_get_layer(&hair->pdata, CD_RADIUS);
+  hair->co = CustomData_get_layer_named(&hair->pdata, CD_PROP_FLOAT3, HAIR_ATTR_POSITION);
+  hair->radius = CustomData_get_layer_named(&hair->pdata, CD_PROP_FLOAT, HAIR_ATTR_RADIUS);
   hair->curves = CustomData_get_layer(&hair->cdata, CD_HAIRCURVE);
   hair->mapping = CustomData_get_layer(&hair->cdata, CD_HAIRMAPPING);
 }
 
+bool BKE_hair_customdata_required(Hair *UNUSED(hair), CustomDataLayer *layer)
+{
+  return layer->type == CD_PROP_FLOAT3 && STREQ(layer->name, HAIR_ATTR_POSITION);
+}
+
 /* Dependency Graph */
 
 Hair *BKE_hair_new_for_eval(const Hair *hair_src, int totpoint, int totcurve)
@@ -294,7 +304,8 @@ static Hair *hair_evaluate_modifiers(struct Depsgraph *depsgraph,
       }
 
       /* Ensure we are not overwriting referenced data. */
-      CustomData_duplicate_referenced_layer(&hair->pdata, CD_LOCATION, hair->totpoint);
+      CustomData_duplicate_referenced_layer_named(
+          &hair->pdata, CD_PROP_FLOAT3, HAIR_ATTR_POSITION, hair->totpoint);
       BKE_hair_update_customdata_pointers(hair);
 
       /* Created deformed coordinates array on demand. */

source/blender/blenkernel/intern/pointcloud.c

@@ -51,6 +51,9 @@
 
 static void pointcloud_random(PointCloud *pointcloud);
 
+const char *POINTCLOUD_ATTR_POSITION = "Position";
+const char *POINTCLOUD_ATTR_RADIUS = "Radius";
+
 static void pointcloud_init_data(ID *id)
 {
   PointCloud *pointcloud = (PointCloud *)id;
@@ -59,8 +62,18 @@ static void pointcloud_init_data(ID *id)
   MEMCPY_STRUCT_AFTER(pointcloud, DNA_struct_default_get(PointCloud), id);
 
   CustomData_reset(&pointcloud->pdata);
-  CustomData_add_layer(&pointcloud->pdata, CD_LOCATION, CD_CALLOC, NULL, pointcloud->totpoint);
-  CustomData_add_layer(&pointcloud->pdata, CD_RADIUS, CD_CALLOC, NULL, pointcloud->totpoint);
+  CustomData_add_layer_named(&pointcloud->pdata,
+                             CD_PROP_FLOAT3,
+                             CD_CALLOC,
+                             NULL,
+                             pointcloud->totpoint,
+                             POINTCLOUD_ATTR_POSITION);
+  CustomData_add_layer_named(&pointcloud->pdata,
+                             CD_PROP_FLOAT,
+                             CD_CALLOC,
+                             NULL,
+                             pointcloud->totpoint,
+                             POINTCLOUD_ATTR_RADIUS);
   BKE_pointcloud_update_customdata_pointers(pointcloud);
 
   pointcloud_random(pointcloud);
@@ -189,8 +202,15 @@ BoundBox *BKE_pointcloud_boundbox_get(Object *ob)
 
 void BKE_pointcloud_update_customdata_pointers(PointCloud *pointcloud)
 {
-  pointcloud->co = CustomData_get_layer(&pointcloud->pdata, CD_LOCATION);
-  pointcloud->radius = CustomData_get_layer(&pointcloud->pdata, CD_RADIUS);
+  pointcloud->co = CustomData_get_layer_named(
+      &pointcloud->pdata, CD_PROP_FLOAT3, POINTCLOUD_ATTR_POSITION);
+  pointcloud->radius = CustomData_get_layer_named(
+      &pointcloud->pdata, CD_PROP_FLOAT, POINTCLOUD_ATTR_RADIUS);
+}
+
+bool BKE_pointcloud_customdata_required(PointCloud *UNUSED(pointcloud), CustomDataLayer *layer)
+{
+  return layer->type == CD_PROP_FLOAT3 && STREQ(layer->name, POINTCLOUD_ATTR_POSITION);
 }
 
 /* Dependency Graph */
@@ -259,7 +279,8 @@ static PointCloud *pointcloud_evaluate_modifiers(struct Depsgraph *depsgraph,
       }
 
       /* Ensure we are not overwriting referenced data. */
-      CustomData_duplicate_referenced_layer(&pointcloud->pdata, CD_LOCATION, pointcloud->totpoint);
+      CustomData_duplicate_referenced_layer_named(
+          &pointcloud->pdata, CD_PROP_FLOAT3, POINTCLOUD_ATTR_POSITION, pointcloud->totpoint);
       BKE_pointcloud_update_customdata_pointers(pointcloud);
 
       /* Created deformed coordinates array on demand. */

source/blender/blenloader/intern/versioning_290.c

@@ -31,8 +31,10 @@
 #include "DNA_genfile.h"
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
+#include "DNA_hair_types.h"
 #include "DNA_modifier_types.h"
 #include "DNA_object_types.h"
+#include "DNA_pointcloud_types.h"
 #include "DNA_rigidbody_types.h"
 #include "DNA_screen_types.h"
 #include "DNA_shader_fx_types.h"
@@ -251,6 +253,25 @@ static void panels_remove_x_closed_flag_recursive(Panel *panel)
   }
 }
 
+static void do_versions_point_attributes(CustomData *pdata)
+{
+  /* Change to generic named float/float3 attributes. */
+  const int CD_LOCATION = 43;
+  const int CD_RADIUS = 44;
+
+  for (int i = 0; i < pdata->totlayer; i++) {
+    CustomDataLayer *layer = &pdata->layers[i];
+    if (layer->type == CD_LOCATION) {
+      STRNCPY(layer->name, "Position");
+      layer->type = CD_PROP_FLOAT3;
+    }
+    else if (layer->type == CD_RADIUS) {
+      STRNCPY(layer->name, "Radius");
+      layer->type = CD_PROP_FLOAT;
+    }
+  }
+}
+
 void blo_do_versions_290(FileData *fd, Library *UNUSED(lib), Main *bmain)
 {
   UNUSED_VARS(fd);
@@ -555,6 +576,15 @@ void blo_do_versions_290(FileData *fd, Library *UNUSED(lib), Main *bmain)
       }
     }
 
+    /* Hair and PointCloud attributes. */
+    for (Hair *hair = bmain->hairs.first; hair != NULL; hair = hair->id.next) {
+      do_versions_point_attributes(&hair->pdata);
+    }
+    for (PointCloud *pointcloud = bmain->pointclouds.first; pointcloud != NULL;
+         pointcloud = pointcloud->id.next) {
+      do_versions_point_attributes(&pointcloud->pdata);
+    }
+
     /* Keep this block, even when empty. */
   }
 }

source/blender/makesdna/DNA_customdata_types.h

@@ -147,9 +147,9 @@ typedef enum CustomDataType {
   CD_CUSTOMLOOPNORMAL = 41,
   CD_SCULPT_FACE_SETS = 42,
 
-  CD_LOCATION = 43,
+  /* CD_LOCATION = 43, */ /* UNUSED */
+  /* CD_RADIUS = 44, */   /* UNUSED */
   CD_HAIRCURVE = 45,
-  CD_RADIUS = 44,
   CD_HAIRMAPPING = 46,
 
   CD_PROP_COLOR = 47,

source/blender/makesrna/intern/rna_attribute.c

@@ -67,6 +67,8 @@ static const EnumPropertyItem rna_enum_attribute_domain_items[] = {
 
 #  include "DEG_depsgraph.h"
 
+#  include "BLT_translation.h"
+
 #  include "WM_api.h"
 
 /* Attribute */
@@ -82,6 +84,17 @@ static void rna_Attribute_name_set(PointerRNA *ptr, const char *value)
   BKE_id_attribute_rename(ptr->owner_id, ptr->data, value, NULL);
 }
 
+static int rna_Attribute_name_editable(PointerRNA *ptr, const char **r_info)
+{
+  CustomDataLayer *layer = ptr->data;
+  if (BKE_id_attribute_required(ptr->owner_id, layer)) {
+    *r_info = N_("Can't modify name of required geometry attribute");
+    return false;
+  }
+
+  return true;
+}
+
 static int rna_Attribute_type_get(PointerRNA *ptr)
 {
   CustomDataLayer *layer = ptr->data;
@@ -551,6 +564,7 @@ static void rna_def_attribute(BlenderRNA *brna)
   prop = RNA_def_property(srna, "name", PROP_STRING, PROP_NONE);
   RNA_def_struct_name_property(srna, prop);
   RNA_def_property_string_funcs(prop, NULL, NULL, "rna_Attribute_name_set");
+  RNA_def_property_editable_func(prop, "rna_Attribute_name_editable");
   RNA_def_property_ui_text(prop, "Name", "Name of the Attribute");
   RNA_def_struct_name_property(srna, prop);