[Bf-blender-cvs] [9635768cdaf] soc-2021-adaptive-cloth: adaptive_cloth: AdaptiveMesh: mark sewing edge verts as preserve

[ishbosamiya]

Commit: 9635768cdafdd13e1f7e3b33277427a3c9c88f05
Author: ishbosamiya
Date:   Tue Aug 31 20:32:55 2021 +0530
Branches: soc-2021-adaptive-cloth
https://developer.blender.org/rB9635768cdafdd13e1f7e3b33277427a3c9c88f05

adaptive_cloth: AdaptiveMesh: mark sewing edge verts as preserve

Mark all verts attached to sewing edge(s) as preserve, this ensures
that no sewing edge(s) are removed which would otherwise lead to
results are not in line with what the artist would want.

===================================================================

M	source/blender/blenkernel/intern/cloth_remesh.cc

===================================================================

diff --git a/source/blender/blenkernel/intern/cloth_remesh.cc b/source/blender/blenkernel/intern/cloth_remesh.cc
index 61b4bd9736e..f908328a70f 100644
--- a/source/blender/blenkernel/intern/cloth_remesh.cc
+++ b/source/blender/blenkernel/intern/cloth_remesh.cc
@@ -408,19 +408,47 @@ class AdaptiveMesh : public Mesh<NodeData<END>, VertData, EdgeData, internal::Em
 
   /**
    * Marks verts which are on a seam or boundary for preserve
+   *
+   * Important to not mess with the panel boundaries so if a vert is
+   * marked for preserve it will not be removed and this takes care of
+   * that.
+   *
+   * It also ensures that when sewing is enabled, all verts attached
+   * to sewing edge(s) are also preserved.
    */
-  void mark_verts_for_preserve()
+  void mark_verts_for_preserve(bool sewing_enabled)
   {
+    const auto set_vert_preserve = [](AdaptiveVert &vert) {
+      auto &op_vert_data = vert.get_extra_data_mut();
+      if (op_vert_data) {
+        auto &vert_data = op_vert_data.value();
+        vert_data.get_flag_mut() |= VERT_PRESERVE;
+      }
+      else {
+        vert.set_extra_data(VertData());
+        vert.get_extra_data_mut().value().get_flag_mut() |= VERT_PRESERVE;
+      }
+    };
+
     for (auto &vert : this->get_verts_mut()) {
       if (this->is_vert_on_seam_or_boundary(vert)) {
-        auto &op_vert_data = vert.get_extra_data_mut();
-        if (op_vert_data) {
-          auto &vert_data = op_vert_data.value();
-          vert_data.get_flag_mut() |= VERT_PRESERVE;
-        }
-        else {
-          vert.set_extra_data(VertData());
-          vert.get_extra_data_mut().value().get_flag_mut() |= VERT_PRESERVE;
+        set_vert_preserve(vert);
+      }
+    }
+
+    /* Mark all verts attached to sewing edge(s) as preserve, this
+     * ensures that no sewing edge(s) are removed which would
+     * otherwise lead to results are not in line with what the artist
+     * would want. */
+    if (sewing_enabled) {
+      for (const auto &edge : this->get_edges()) {
+        if (edge.is_loose()) {
+          const auto [v1_index, v2_index] = edge.get_checked_verts();
+          auto &v1 = this->get_checked_vert(v1_index);
+          set_vert_preserve(v1);
+
+          auto &v2 = this->get_checked_vert(v2_index);
+          set_vert_preserve(v2);
         }
       }
     }
@@ -1660,7 +1688,8 @@ Mesh *adaptive_remesh(const AdaptiveRemeshParams<END, ExtraData> &params,
   /* Important to not mess with the panel boundaries so if a vert is
    * marked for preserve it will not be removed and this takes care of
    * that. */
-  adaptive_mesh.mark_verts_for_preserve();
+  bool sewing_enabled = params.flags & ADAPTIVE_REMESH_PARAMS_SEWING;
+  adaptive_mesh.mark_verts_for_preserve(sewing_enabled);
 
   /* Actual Remeshing Part */
   {