Merge branch 'blender-v3.2-release'

5 files changed, 190 insertions, 1 deletions

diff --git a/source/blender/blenkernel/BKE_mesh.h b/source/blender/blenkernel/BKE_mesh.h
index bd9bacb52c1..091f30825ae 100644
--- a/source/blender/blenkernel/BKE_mesh.h
+++ b/source/blender/blenkernel/BKE_mesh.h
@@ -893,6 +893,14 @@ struct Mesh *BKE_mesh_merge_verts(struct Mesh *mesh,
                                   int tot_vtargetmap,
                                   int merge_mode);
 
+/**
+ * Account for custom-data such as UV's becoming detached because of of imprecision
+ * in custom-data interpolation.
+ * Without running this operation subdivision surface can cause UV's to be disconnected,
+ * see: T81065.
+ */
+void BKE_mesh_merge_customdata_for_apply_modifier(struct Mesh *me);
+
 /* Flush flags. */
 
 /**
diff --git a/source/blender/blenkernel/CMakeLists.txt b/source/blender/blenkernel/CMakeLists.txt
index 54743be4305..c9e88362b80 100644
--- a/source/blender/blenkernel/CMakeLists.txt
+++ b/source/blender/blenkernel/CMakeLists.txt
@@ -199,6 +199,7 @@ set(SRC
   intern/mesh_iterators.c
   intern/mesh_mapping.c
   intern/mesh_merge.c
+  intern/mesh_merge_customdata.cc
   intern/mesh_mirror.c
   intern/mesh_normals.cc
   intern/mesh_remap.c
diff --git a/source/blender/blenkernel/intern/mesh_merge_customdata.cc b/source/blender/blenkernel/intern/mesh_merge_customdata.cc
new file mode 100644
index 00000000000..adaf378ed27
--- /dev/null
+++ b/source/blender/blenkernel/intern/mesh_merge_customdata.cc
@@ -0,0 +1,137 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup bke
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+
+#include "BLI_math.h"
+#include "BLI_task.hh"
+#include "BLI_utildefines.h"
+
+#include "BKE_customdata.h"
+#include "BKE_mesh.h"
+#include "BKE_mesh_mapping.h"
+#include "BLI_memarena.h"
+
+#include "BLI_strict_flags.h"
+
+using namespace blender;
+
+enum {
+  CMP_CLOSE = 0,
+  CMP_EQUAL = 1,
+  CMP_APART = 2,
+};
+
+static int compare_v2_classify(const float uv_a[2], const float uv_b[2])
+{
+  if (uv_a[0] == uv_b[0] && uv_a[1] == uv_b[1]) {
+    return CMP_EQUAL;
+  }
+  /* Note that the ULP value is the primary value used to compare relative values
+   * as the absolute value doesn't account for float precision at difference scales.
+   * - For subdivision-surface ULP of 3 is sufficient,
+   *   although this value is extremely small.
+   * - For bevel the URL of 12 is sufficient to merge UV's that appear to be connected
+   *   with bevel on Suzanne beveled 15% with 6 segments.
+   *
+   * These values could be tweaked but should be kept on the small side to prevent
+   * unintentional joining of intentionally dis-connected UV's.
+   *
+   * Before v2.91 the threshold was either (`1e-4` or `0.05 / image_size` for selection picking).
+   * So picking used a threshold of `1e-4` for a 500x500 image and `1e-5` for a 5000x5000 image.
+   * Given this value worked reasonably well for a long time, the absolute difference should
+   * never exceed `1e-4` (#STD_UV_CONNECT_LIMIT which is still used in a few areas). */
+  const float diff_abs = 1e-12f;
+  const int diff_ulp = 12;
+
+  if (compare_ff_relative(uv_a[0], uv_b[0], diff_abs, diff_ulp) &&
+      compare_ff_relative(uv_a[1], uv_b[1], diff_abs, diff_ulp)) {
+    return CMP_CLOSE;
+  }
+  return CMP_APART;
+}
+
+static void merge_uvs_for_vertex(const Span<int> loops_for_vert, Span<MLoopUV *> mloopuv_layers)
+{
+  if (loops_for_vert.size() <= 1) {
+    return;
+  }
+  /* Manipulate a copy of the loop indices, de-duplicating UV's per layer.  */
+  Vector<int, 32> loops_merge;
+  loops_merge.reserve(loops_for_vert.size());
+  for (MLoopUV *mloopuv : mloopuv_layers) {
+    BLI_assert(loops_merge.is_empty());
+    loops_merge.extend_unchecked(loops_for_vert);
+    while (loops_merge.size() > 1) {
+      uint i_last = (uint)loops_merge.size() - 1;
+      const float *uv_src = mloopuv[loops_merge[0]].uv;
+      for (uint i = 1; i <= i_last;) {
+        float *uv_dst = mloopuv[loops_merge[i]].uv;
+        switch (compare_v2_classify(uv_src, uv_dst)) {
+          case CMP_CLOSE: {
+            uv_dst[0] = uv_src[0];
+            uv_dst[1] = uv_src[1];
+            ATTR_FALLTHROUGH;
+          }
+          case CMP_EQUAL: {
+            loops_merge[i] = loops_merge[i_last--];
+            break;
+          }
+          case CMP_APART: {
+            /* Doesn't match, check the next UV. */
+            i++;
+            break;
+          }
+          default: {
+            BLI_assert_unreachable();
+          }
+        }
+      }
+      /* Finished de-duplicating with the first index, throw it away. */
+      loops_merge[0] = loops_merge[i_last];
+      loops_merge.resize(i_last);
+    }
+    loops_merge.clear();
+  }
+}
+
+void BKE_mesh_merge_customdata_for_apply_modifier(Mesh *me)
+{
+  if (me->totloop == 0) {
+    return;
+  }
+  const int mloopuv_layers_num = CustomData_number_of_layers(&me->ldata, CD_MLOOPUV);
+  if (mloopuv_layers_num == 0) {
+    return;
+  }
+
+  int *vert_map_mem;
+  struct MeshElemMap *vert_to_loop;
+  BKE_mesh_vert_loop_map_create(
+      &vert_to_loop, &vert_map_mem, me->mpoly, me->mloop, me->totvert, me->totpoly, me->totloop);
+
+  Vector<MLoopUV *> mloopuv_layers;
+  mloopuv_layers.reserve(mloopuv_layers_num);
+  for (int a = 0; a < mloopuv_layers_num; a++) {
+    MLoopUV *mloopuv = static_cast<MLoopUV *>(CustomData_get_layer_n(&me->ldata, CD_MLOOPUV, a));
+    mloopuv_layers.append_unchecked(mloopuv);
+  }
+
+  Span<MLoopUV *> mloopuv_layers_as_span = mloopuv_layers.as_span();
+  threading::parallel_for(IndexRange(me->totvert), 1024, [&](IndexRange range) {
+    for (const int64_t v_index : range) {
+      MeshElemMap &loops_for_vert = vert_to_loop[v_index];
+      Span<int> loops_for_vert_span(loops_for_vert.indices, loops_for_vert.count);
+      merge_uvs_for_vertex(loops_for_vert_span, mloopuv_layers_as_span);
+    }
+  });
+
+  MEM_freeN(vert_to_loop);
+  MEM_freeN(vert_map_mem);
+}
diff --git a/source/blender/editors/object/object_add.cc b/source/blender/editors/object/object_add.cc
index 5b857d2dba1..db8860efdd8 100644
--- a/source/blender/editors/object/object_add.cc
+++ b/source/blender/editors/object/object_add.cc
@@ -2894,6 +2894,7 @@ static int object_convert_exec(bContext *C, wmOperator *op)
   Object *ob1, *obact = CTX_data_active_object(C);
   const short target = RNA_enum_get(op->ptr, "target");
   bool keep_original = RNA_boolean_get(op->ptr, "keep_original");
+  const bool do_merge_customdata = RNA_boolean_get(op->ptr, "merge_customdata");
 
   const float angle = RNA_float_get(op->ptr, "angle");
   const int thickness = RNA_int_get(op->ptr, "thickness");
@@ -3122,6 +3123,10 @@ static int object_convert_exec(bContext *C, wmOperator *op)
       Mesh *new_mesh = (Mesh *)newob->data;
       BKE_mesh_nomain_to_mesh(me_eval, new_mesh, newob, &CD_MASK_MESH, true);
 
+      if (do_merge_customdata) {
+        BKE_mesh_merge_customdata_for_apply_modifier(new_mesh);
+      }
+
       /* Anonymous attributes shouldn't be available on the applied geometry. */
       MeshComponent component;
       component.replace(new_mesh, GeometryOwnershipType::Editable);
@@ -3441,7 +3446,11 @@ static void object_convert_ui(bContext *UNUSED(C), wmOperator *op)
   uiItemR(layout, op->ptr, "target", 0, nullptr, ICON_NONE);
   uiItemR(layout, op->ptr, "keep_original", 0, nullptr, ICON_NONE);
 
-  if (RNA_enum_get(op->ptr, "target") == OB_GPENCIL) {
+  const int target = RNA_enum_get(op->ptr, "target");
+  if (target == OB_MESH) {
+    uiItemR(layout, op->ptr, "merge_customdata", 0, nullptr, ICON_NONE);
+  }
+  else if (target == OB_GPENCIL) {
     uiItemR(layout, op->ptr, "thickness", 0, nullptr, ICON_NONE);
     uiItemR(layout, op->ptr, "angle", 0, nullptr, ICON_NONE);
     uiItemR(layout, op->ptr, "offset", 0, nullptr, ICON_NONE);
@@ -3477,6 +3486,13 @@ void OBJECT_OT_convert(wmOperatorType *ot)
                   "Keep Original",
                   "Keep original objects instead of replacing them");
 
+  RNA_def_boolean(
+      ot->srna,
+      "merge_customdata",
+      true,
+      "Merge UV's",
+      "Merge UV coordinates that share a vertex to account for imprecision in some modifiers");
+
   prop = RNA_def_float_rotation(ot->srna,
                                 "angle",
                                 0,
diff --git a/source/blender/editors/object/object_modifier.cc b/source/blender/editors/object/object_modifier.cc
index f90a31a7cbe..3328fe65f2e 100644
--- a/source/blender/editors/object/object_modifier.cc
+++ b/source/blender/editors/object/object_modifier.cc
@@ -1434,8 +1434,10 @@ static int modifier_apply_exec_ex(bContext *C, wmOperator *op, int apply_as, boo
   Scene *scene = CTX_data_scene(C);
   Object *ob = ED_object_active_context(C);
   ModifierData *md = edit_modifier_property_get(op, ob, 0);
+  const ModifierTypeInfo *mti = BKE_modifier_get_info((ModifierType)md->type);
   const bool do_report = RNA_boolean_get(op->ptr, "report");
   const bool do_single_user = RNA_boolean_get(op->ptr, "single_user");
+  const bool do_merge_customdata = RNA_boolean_get(op->ptr, "merge_customdata");
 
   if (md == nullptr) {
     return OPERATOR_CANCELLED;
@@ -1460,6 +1462,11 @@ static int modifier_apply_exec_ex(bContext *C, wmOperator *op, int apply_as, boo
     return OPERATOR_CANCELLED;
   }
 
+  if (do_merge_customdata &&
+      (mti->type & (eModifierTypeType_Constructive | eModifierTypeType_Nonconstructive))) {
+    BKE_mesh_merge_customdata_for_apply_modifier((Mesh *)ob->data);
+  }
+
   DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
   DEG_relations_tag_update(bmain);
   WM_event_add_notifier(C, NC_OBJECT | ND_MODIFIER, ob);
@@ -1518,6 +1525,12 @@ void OBJECT_OT_modifier_apply(wmOperatorType *ot)
   edit_modifier_properties(ot);
   edit_modifier_report_property(ot);
 
+  RNA_def_boolean(
+      ot->srna,
+      "merge_customdata",
+      true,
+      "Merge UV's",
+      "Merge UV coordinates that share a vertex to account for imprecision in some modifiers");
   PropertyRNA *prop = RNA_def_boolean(ot->srna,
                                       "single_user",
                                       false,
@@ -1599,11 +1612,18 @@ static int modifier_convert_exec(bContext *C, wmOperator *op)
   ViewLayer *view_layer = CTX_data_view_layer(C);
   Object *ob = ED_object_active_context(C);
   ModifierData *md = edit_modifier_property_get(op, ob, 0);
+  const ModifierTypeInfo *mti = BKE_modifier_get_info((ModifierType)md->type);
+  const bool do_merge_customdata = RNA_boolean_get(op->ptr, "merge_customdata");
 
   if (!md || !ED_object_modifier_convert(op->reports, bmain, depsgraph, view_layer, ob, md)) {
     return OPERATOR_CANCELLED;
   }
 
+  if (do_merge_customdata &&
+      (mti->type & (eModifierTypeType_Constructive | eModifierTypeType_Nonconstructive))) {
+    BKE_mesh_merge_customdata_for_apply_modifier((Mesh *)ob->data);
+  }
+
   DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
   WM_event_add_notifier(C, NC_OBJECT | ND_MODIFIER, ob);
 
@@ -1631,6 +1651,13 @@ void OBJECT_OT_modifier_convert(wmOperatorType *ot)
   /* flags */
   ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
   edit_modifier_properties(ot);
+
+  RNA_def_boolean(
+      ot->srna,
+      "merge_customdata",
+      true,
+      "Merge UV's",
+      "Merge UV coordinates that share a vertex to account for imprecision in some modifiers");
 }
 
 /** \} */