Curves: add surface object pointer

Ref T95776.

Differential Revision: https://developer.blender.org/D14182

release/scripts/startup/bl_ui/properties_data_curves.py

@@ -35,6 +35,17 @@ class DATA_PT_context_curves(DataButtonsPanel, Panel):
             layout.template_ID(space, "pin_id")
 
 
+class DATA_PT_curves_surface(DataButtonsPanel, Panel):
+    bl_label = "Surface"
+    COMPAT_ENGINES = {'BLENDER_RENDER', 'BLENDER_EEVEE', 'BLENDER_WORKBENCH'}
+
+    def draw(self, context):
+        layout = self.layout
+        ob = context.object
+
+        layout.prop(ob.data, "surface")
+
+
 class CURVES_MT_add_attribute(Menu):
     bl_label = "Add Attribute"
 
@@ -115,6 +126,7 @@ class DATA_PT_custom_props_curves(DataButtonsPanel, PropertyPanel, Panel):
 classes = (
     DATA_PT_context_curves,
     DATA_PT_CURVES_attributes,
+    DATA_PT_curves_surface,
     DATA_PT_custom_props_curves,
     CURVES_MT_add_attribute,
     CURVES_UL_attributes,

source/blender/blenkernel/intern/curves.cc

@@ -114,6 +114,7 @@ static void curves_foreach_id(ID *id, LibraryForeachIDData *data)
   for (int i = 0; i < curves->totcol; i++) {
     BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, curves->mat[i], IDWALK_CB_USER);
   }
+  BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, curves->surface, IDWALK_CB_NOP);
 }
 
 static void curves_blend_write(BlendWriter *writer, ID *id, const void *id_address)
@@ -186,6 +187,7 @@ static void curves_blend_read_lib(BlendLibReader *reader, ID *id)
   for (int a = 0; a < curves->totcol; a++) {
     BLO_read_id_address(reader, curves->id.lib, &curves->mat[a]);
   }
+  BLO_read_id_address(reader, curves->id.lib, &curves->surface);
 }
 
 static void curves_blend_read_expand(BlendExpander *expander, ID *id)
@@ -194,6 +196,7 @@ static void curves_blend_read_expand(BlendExpander *expander, ID *id)
   for (int a = 0; a < curves->totcol; a++) {
     BLO_expand(expander, curves->mat[a]);
   }
+  BLO_expand(expander, curves->surface);
 }
 
 IDTypeInfo IDType_ID_CV = {

source/blender/blenkernel/intern/lib_query.c

@@ -448,7 +448,7 @@ uint64_t BKE_library_id_can_use_filter_id(const ID *id_owner)
     case ID_WS:
       return FILTER_ID_SCE;
     case ID_CV:
-      return FILTER_ID_MA;
+      return FILTER_ID_MA | FILTER_ID_OB;
     case ID_PT:
       return FILTER_ID_MA;
     case ID_VO:

source/blender/makesdna/DNA_curves_types.h

@@ -115,6 +115,15 @@ typedef struct Curves {
   short totcol;
   short _pad2[3];
 
+  /**
+   * Used as base mesh when curves represent e.g. hair or fur. This surface is used in edit modes.
+   * When set, the curves will have attributes that indicate a position on this surface. This is
+   * used for deforming the curves when the surface is deformed dynamically.
+   *
+   * This is expected to be a mesh object.
+   */
+  struct Object *surface;
+
   /* Draw Cache. */
   void *batch_cache;
 } Curves;

source/blender/makesrna/intern/rna_curves.c

@@ -16,6 +16,8 @@
 #include "BLI_math_base.h"
 #include "BLI_string.h"
 
+#include "WM_types.h"
+
 #ifdef RNA_RUNTIME
 
 #  include "BLI_math_vector.h"
@@ -265,6 +267,13 @@ static void rna_def_curves(BlenderRNA *brna)
   RNA_def_property_collection_funcs(
       prop, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "rna_IDMaterials_assign_int");
 
+  prop = RNA_def_property(srna, "surface", PROP_POINTER, PROP_NONE);
+  RNA_def_property_struct_type(prop, "Object");
+  RNA_def_property_flag(prop, PROP_EDITABLE);
+  RNA_def_property_pointer_funcs(prop, NULL, NULL, NULL, "rna_Mesh_object_poll");
+  RNA_def_property_ui_text(prop, "Surface", "Mesh object that the curves can be attached to");
+  RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, NULL);
+
   /* attributes */
   rna_def_attributes_common(srna);