Sculpt: Cloth Filter

This tool is similar to the cloth brush, but it applies the cloth
simulation deformation to the whole mesh in an uniform way. The
simulation can be controlled using the mask to pin vertices and the face
sets to define force action areas.

It uses the same solver as the cloth brush which now no longer depends
on StrokeCache.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D7857

release/scripts/presets/keyconfig/keymap_data/blender_default.py

@@ -6272,6 +6272,16 @@ def km_3d_view_tool_sculpt_mesh_filter(params):
         ]},
     )
 
+def km_3d_view_tool_sculpt_cloth_filter(params):
+    return (
+        "3D View Tool: Sculpt, Cloth Filter",
+        {"space_type": 'VIEW_3D', "region_type": 'WINDOW'},
+        {"items": [
+            ("sculpt.cloth_filter", {"type": params.tool_tweak, "value": 'ANY'},
+             None)
+        ]},
+    )
+
 def km_3d_view_tool_paint_weight_sample_weight(params):
     return (
         "3D View Tool: Paint Weight, Sample Weight",
@@ -6811,6 +6821,7 @@ def generate_keymaps(params=None):
         km_3d_view_tool_sculpt_box_mask(params),
         km_3d_view_tool_sculpt_lasso_mask(params),
         km_3d_view_tool_sculpt_mesh_filter(params),
+        km_3d_view_tool_sculpt_cloth_filter(params),
         km_3d_view_tool_paint_weight_sample_weight(params),
         km_3d_view_tool_paint_weight_sample_vertex_group(params),
         km_3d_view_tool_paint_weight_gradient(params),

release/scripts/startup/bl_ui/space_toolsystem_toolbar.py

@@ -1228,6 +1228,25 @@ class _defs_sculpt:
             draw_settings=draw_settings,
         )
 
+    @ToolDef.from_fn
+    def cloth_filter():
+        def draw_settings(_context, layout, tool):
+            props = tool.operator_properties("sculpt.cloth_filter")
+            layout.prop(props, "type", expand=False)
+            layout.prop(props, "strength")
+            layout.prop(props, "cloth_mass")
+            layout.prop(props, "cloth_damping")
+            layout.prop(props, "use_face_sets")
+
+        return dict(
+            idname="builtin.cloth_filter",
+            label="Cloth Filter",
+            icon="ops.sculpt.cloth_filter",
+            widget=None,
+            keymap=(),
+            draw_settings=draw_settings,
+        )
+
 
 class _defs_vertex_paint:
 
@@ -2402,6 +2421,7 @@ class VIEW3D_PT_tools_active(ToolSelectPanelHelper, Panel):
             _defs_sculpt.hide_border,
             None,
             _defs_sculpt.mesh_filter,
+            _defs_sculpt.cloth_filter,
             None,
             _defs_transform.translate,
             _defs_transform.rotate,

source/blender/editors/sculpt_paint/sculpt.c

@@ -7898,4 +7898,5 @@ void ED_operatortypes_sculpt(void)
   WM_operatortype_append(SCULPT_OT_face_sets_change_visibility);
   WM_operatortype_append(SCULPT_OT_face_sets_randomize_colors);
   WM_operatortype_append(SCULPT_OT_face_sets_init);
+  WM_operatortype_append(SCULPT_OT_cloth_filter);
 }

source/blender/editors/sculpt_paint/sculpt_automasking.c

@@ -91,7 +91,7 @@ bool SCULPT_is_automasking_enabled(const Sculpt *sd, const SculptSession *ss, co
 
 float SCULPT_automasking_factor_get(SculptSession *ss, int vert)
 {
-  if (ss->cache->automask) {
+  if (ss->cache && ss->cache->automask) {
     return ss->cache->automask[vert];
   }
   else {

source/blender/editors/sculpt_paint/sculpt_cloth.c

@@ -106,9 +106,11 @@
 #define CLOTH_MAX_CONSTRAINTS_PER_VERTEX 1024
 #define CLOTH_SIMULATION_TIME_STEP 0.01f
 
-static void cloth_brush_add_length_constraint(SculptSession *ss, const int v1, const int v2)
+static void cloth_brush_add_length_constraint(SculptSession *ss,
+                                              SculptClothSimulation *cloth_sim,
+                                              const int v1,
+                                              const int v2)
 {
-  SculptClothSimulation *cloth_sim = ss->cache->cloth_sim;
   cloth_sim->length_constraints[cloth_sim->tot_length_constraints].v1 = v1;
   cloth_sim->length_constraints[cloth_sim->tot_length_constraints].v2 = v2;
   cloth_sim->length_constraints[cloth_sim->tot_length_constraints].length = len_v3v3(
@@ -133,12 +135,11 @@ static void do_cloth_brush_build_constraints_task_cb_ex(
   SculptSession *ss = data->ob->sculpt;
 
   PBVHVertexIter vd;
-  const float radius = ss->cache->initial_radius;
-  const float limit = radius + (radius * data->brush->cloth_sim_limit);
 
   BKE_pbvh_vertex_iter_begin(ss->pbvh, data->nodes[n], vd, PBVH_ITER_UNIQUE)
   {
-    if (len_squared_v3v3(vd.co, ss->cache->initial_location) < limit * limit) {
+    if (len_squared_v3v3(vd.co, data->cloth_sim_initial_location) <
+        data->cloth_sim_radius * data->cloth_sim_radius) {
 
       SculptVertexNeighborIter ni;
       int build_indices[CLOTH_MAX_CONSTRAINTS_PER_VERTEX];
@@ -159,7 +160,8 @@ static void do_cloth_brush_build_constraints_task_cb_ex(
       for (int c_i = 0; c_i < tot_indices; c_i++) {
         for (int c_j = 0; c_j < tot_indices; c_j++) {
           if (c_i != c_j) {
-            cloth_brush_add_length_constraint(ss, build_indices[c_i], build_indices[c_j]);
+            cloth_brush_add_length_constraint(
+                ss, data->cloth_sim, build_indices[c_i], build_indices[c_j]);
           }
         }
       }
@@ -192,11 +194,11 @@ static float cloth_brush_simulation_falloff_get(const Brush *brush,
   }
 }
 
-static void cloth_brush_apply_force_to_vertex(SculptSession *ss,
+static void cloth_brush_apply_force_to_vertex(SculptSession *UNUSED(ss),
+                                              SculptClothSimulation *cloth_sim,
                                               const float force[3],
                                               const int vertex_index)
 {
-  SculptClothSimulation *cloth_sim = ss->cache->cloth_sim;
   madd_v3_v3fl(cloth_sim->acceleration[vertex_index], force, 1.0f / cloth_sim->mass);
 }
 
@@ -290,7 +292,6 @@ static void do_cloth_brush_apply_forces_task_cb_ex(void *__restrict userdata,
 
       float brush_disp[3];
       float normal[3];
-
       if (vd.no) {
         normal_short_to_float_v3(normal, vd.no);
       }
@@ -348,13 +349,15 @@ static void do_cloth_brush_apply_forces_task_cb_ex(void *__restrict userdata,
 
       madd_v3_v3fl(force, gravity, fade);
 
-      cloth_brush_apply_force_to_vertex(ss, force, vd.index);
+      cloth_brush_apply_force_to_vertex(ss, ss->cache->cloth_sim, force, vd.index);
     }
   }
   BKE_pbvh_vertex_iter_end;
 }
 
-static SculptClothSimulation *cloth_brush_simulation_create(SculptSession *ss, Brush *brush)
+static SculptClothSimulation *cloth_brush_simulation_create(SculptSession *ss,
+                                                            const float cloth_mass,
+                                                            const float cloth_damping)
 {
   const int totverts = SCULPT_vertex_count_get(ss);
   SculptClothSimulation *cloth_sim;
@@ -373,8 +376,8 @@ static SculptClothSimulation *cloth_brush_simulation_create(SculptSession *ss, B
   cloth_sim->length_constraint_tweak = MEM_callocN(sizeof(float) * totverts,
                                                    "cloth sim length tweak");
 
-  cloth_sim->mass = brush->cloth_mass;
-  cloth_sim->damping = brush->cloth_damping;
+  cloth_sim->mass = cloth_mass;
+  cloth_sim->damping = cloth_damping;
 
   return cloth_sim;
 }
@@ -386,12 +389,16 @@ static void do_cloth_brush_solve_simulation_task_cb_ex(
   SculptSession *ss = data->ob->sculpt;
   const Brush *brush = data->brush;
   PBVHVertexIter vd;
-  SculptClothSimulation *cloth_sim = ss->cache->cloth_sim;
+  SculptClothSimulation *cloth_sim = data->cloth_sim;
   const float time_step = data->cloth_time_step;
   BKE_pbvh_vertex_iter_begin(ss->pbvh, data->nodes[n], vd, PBVH_ITER_UNIQUE)
   {
-    const float sim_factor = cloth_brush_simulation_falloff_get(
-        brush, ss->cache->radius, ss->cache->initial_location, cloth_sim->init_pos[vd.index]);
+    const float sim_factor = ss->cache ? cloth_brush_simulation_falloff_get(
+                                             brush,
+                                             ss->cache->radius,
+                                             ss->cache->initial_location,
+                                             cloth_sim->init_pos[vd.index]) :
+                                         1.0f;
     if (sim_factor > 0.0f) {
       int i = vd.index;
       float temp[3];
@@ -412,7 +419,7 @@ static void do_cloth_brush_solve_simulation_task_cb_ex(
 
       copy_v3_fl(cloth_sim->acceleration[i], 0.0f);
 
-      copy_v3_v3(vd.co, ss->cache->cloth_sim->pos[vd.index]);
+      copy_v3_v3(vd.co, cloth_sim->pos[vd.index]);
       if (vd.mvert) {
         vd.mvert->flag |= ME_VERT_PBVH_UPDATE;
       }
@@ -424,7 +431,10 @@ static void do_cloth_brush_solve_simulation_task_cb_ex(
 static void cloth_brush_build_nodes_constraints(Sculpt *sd,
                                                 Object *ob,
                                                 PBVHNode **nodes,
-                                                int totnode)
+                                                int totnode,
+                                                SculptClothSimulation *cloth_sim,
+                                                float initial_location[3],
+                                                const float radius)
 {
   Brush *brush = BKE_paint_brush(&sd->paint);
 
@@ -440,6 +450,9 @@ static void cloth_brush_build_nodes_constraints(Sculpt *sd,
       .ob = ob,
       .brush = brush,
       .nodes = nodes,
+      .cloth_sim = cloth_sim,
+      .cloth_sim_initial_location = initial_location,
+      .cloth_sim_radius = radius,
   };
   BLI_task_parallel_range(
       0, totnode, &build_constraints_data, do_cloth_brush_build_constraints_task_cb_ex, &settings);
@@ -480,10 +493,18 @@ static void cloth_brush_satisfy_constraints(SculptSession *ss,
       const float mask_v2 = (1.0f - SCULPT_vertex_mask_get(ss, v2)) *
                             SCULPT_automasking_factor_get(ss, v2);
 
-      const float sim_factor_v1 = cloth_brush_simulation_falloff_get(
-          brush, ss->cache->radius, ss->cache->initial_location, cloth_sim->init_pos[v1]);
-      const float sim_factor_v2 = cloth_brush_simulation_falloff_get(
-          brush, ss->cache->radius, ss->cache->initial_location, cloth_sim->init_pos[v2]);
+      const float sim_factor_v1 = ss->cache ? cloth_brush_simulation_falloff_get(
+                                                  brush,
+                                                  ss->cache->radius,
+                                                  ss->cache->initial_location,
+                                                  cloth_sim->init_pos[v1]) :
+                                              1.0f;
+      const float sim_factor_v2 = ss->cache ? cloth_brush_simulation_falloff_get(
+                                                  brush,
+                                                  ss->cache->radius,
+                                                  ss->cache->initial_location,
+                                                  cloth_sim->init_pos[v2]) :
+                                              1.0f;
 
       madd_v3_v3fl(cloth_sim->pos[v1], correction_vector_half, 1.0f * mask_v1 * sim_factor_v1);
       madd_v3_v3fl(cloth_sim->pos[v2], correction_vector_half, -1.0f * mask_v2 * sim_factor_v2);
@@ -491,13 +512,12 @@ static void cloth_brush_satisfy_constraints(SculptSession *ss,
   }
 }
 
-static void cloth_brush_do_simulation_step(Sculpt *sd, Object *ob, PBVHNode **nodes, int totnode)
+static void cloth_brush_do_simulation_step(
+    Sculpt *sd, Object *ob, SculptClothSimulation *cloth_sim, PBVHNode **nodes, int totnode)
 {
   SculptSession *ss = ob->sculpt;
   Brush *brush = BKE_paint_brush(&sd->paint);
 
-  SculptClothSimulation *cloth_sim = ss->cache->cloth_sim;
-
   /* Update the constraints. */
   cloth_brush_satisfy_constraints(ss, brush, cloth_sim);
 
@@ -508,6 +528,7 @@ static void cloth_brush_do_simulation_step(Sculpt *sd, Object *ob, PBVHNode **no
       .brush = brush,
       .nodes = nodes,
       .cloth_time_step = CLOTH_SIMULATION_TIME_STEP,
+      .cloth_sim = cloth_sim,
   };
 
   TaskParallelSettings settings;
@@ -608,7 +629,8 @@ void SCULPT_do_cloth_brush(Sculpt *sd, Object *ob, PBVHNode **nodes, int totnode
 
     /* The simulation structure only needs to be created on the first symmetry pass. */
     if (ss->cache->mirror_symmetry_pass == 0) {
-      ss->cache->cloth_sim = cloth_brush_simulation_create(ss, brush);
+      ss->cache->cloth_sim = cloth_brush_simulation_create(
+          ss, brush->cloth_mass, brush->cloth_damping);
       for (int i = 0; i < totverts; i++) {
         copy_v3_v3(ss->cache->cloth_sim->prev_pos[i], SCULPT_vertex_co_get(ss, i));
         copy_v3_v3(ss->cache->cloth_sim->init_pos[i], SCULPT_vertex_co_get(ss, i));
@@ -616,7 +638,10 @@ void SCULPT_do_cloth_brush(Sculpt *sd, Object *ob, PBVHNode **nodes, int totnode
     }
 
     /* Build the constraints. */
-    cloth_brush_build_nodes_constraints(sd, ob, nodes, totnode);
+    const float radius = ss->cache->initial_radius;
+    const float limit = radius + (radius * brush->cloth_sim_limit);
+    cloth_brush_build_nodes_constraints(
+        sd, ob, nodes, totnode, ss->cache->cloth_sim, ss->cache->location, limit);
 
     return;
   }
@@ -630,7 +655,7 @@ void SCULPT_do_cloth_brush(Sculpt *sd, Object *ob, PBVHNode **nodes, int totnode
   cloth_brush_apply_brush_foces(sd, ob, nodes, totnode);
 
   /* Update and write the simulation to the nodes. */
-  cloth_brush_do_simulation_step(sd, ob, nodes, totnode);
+  cloth_brush_do_simulation_step(sd, ob, ss->cache->cloth_sim, nodes, totnode);
 
   return;
 }
@@ -706,3 +731,246 @@ void SCULPT_cloth_plane_falloff_preview_draw(const uint gpuattr,
 
   immEnd();
 }
+
+/* Cloth Filter. */
+
+typedef enum eSculpClothFilterType {
+  CLOTH_FILTER_GRAVITY,
+  CLOTH_FILTER_INFLATE,
+  CLOTH_FILTER_EXPAND,
+  CLOTH_FILTER_PINCH,
+} eSculptClothFilterType;
+
+static EnumPropertyItem prop_cloth_filter_type[] = {
+    {CLOTH_FILTER_GRAVITY, "GRAVITY", 0, "Gravity", "Applies gravity to the simulation"},
+    {CLOTH_FILTER_INFLATE, "INFLATE", 0, "Inflate", "Inflates the cloth"},
+    {CLOTH_FILTER_EXPAND, "EXPAND", 0, "Expand", "Expands the cloth's dimensions"},
+    {CLOTH_FILTER_PINCH,
+     "PINCH",
+     0,
+     "Pinch",
+     "Pinches the cloth to the point were the cursor was when the filter started"},
+    {0, NULL, 0, NULL, NULL},
+};
+
+static void cloth_filter_apply_forces_task_cb(void *__restrict userdata,
+                                              const int i,
+                                              const TaskParallelTLS *__restrict UNUSED(tls))
+{
+  SculptThreadedTaskData *data = userdata;
+  Sculpt *sd = data->sd;
+  SculptSession *ss = data->ob->sculpt;
+  PBVHNode *node = data->nodes[i];
+
+  SculptClothSimulation *cloth_sim = ss->filter_cache->cloth_sim;
+  const int filter_type = data->filter_type;
+
+  float sculpt_gravity[3] = {0.0f};
+  if (sd->gravity_object) {
+    copy_v3_v3(sculpt_gravity, sd->gravity_object->obmat[2]);
+  }
+  else {
+    sculpt_gravity[2] = -1.0f;
+  }
+  mul_v3_fl(sculpt_gravity, sd->gravity_factor * data->filter_strength);
+
+  PBVHVertexIter vd;
+  BKE_pbvh_vertex_iter_begin(ss->pbvh, node, vd, PBVH_ITER_UNIQUE)
+  {
+    float fade = vd.mask ? *vd.mask : 0.0f;
+    fade = 1.0f - fade;
+    float force[3] = {0.0f, 0.0f, 0.0f};
+
+    if (ss->filter_cache->active_face_set != SCULPT_FACE_SET_NONE) {
+      if (!SCULPT_vertex_has_face_set(ss, vd.index, ss->filter_cache->active_face_set)) {
+        continue;
+      }
+    }
+
+    switch (filter_type) {
+      case CLOTH_FILTER_GRAVITY:
+        force[2] = -data->filter_strength * fade;
+        break;
+      case CLOTH_FILTER_INFLATE: {
+        float normal[3];
+        SCULPT_vertex_normal_get(ss, vd.index, normal);
+        mul_v3_v3fl(force, normal, fade * data->filter_strength);
+      } break;
+      case CLOTH_FILTER_EXPAND:
+        cloth_sim->length_constraint_tweak[vd.index] += fade * data->filter_strength * 0.01f;
+        zero_v3(force);
+        break;
+      case CLOTH_FILTER_PINCH:
+        sub_v3_v3v3(force, ss->filter_cache->cloth_sim_pinch_point, vd.co);
+        normalize_v3(force);
+        mul_v3_fl(force, fade * data->filter_strength);
+        break;
+    }
+
+    add_v3_v3(force, sculpt_gravity);
+
+    cloth_brush_apply_force_to_vertex(ss, cloth_sim, force, vd.index);
+  }
+  BKE_pbvh_vertex_iter_end;
+
+  BKE_pbvh_node_mark_update(node);
+}
+
+static int sculpt_cloth_filter_modal(bContext *C, wmOperator *op, const wmEvent *event)
+{
+  Object *ob = CTX_data_active_object(C);
+  Depsgraph *depsgraph = CTX_data_depsgraph_pointer(C);
+  SculptSession *ss = ob->sculpt;
+  Sculpt *sd = CTX_data_tool_settings(C)->sculpt;
+  int filter_type = RNA_enum_get(op->ptr, "type");
+  float filter_strength = RNA_float_get(op->ptr, "strength");
+
+  if (event->type == LEFTMOUSE && event->val == KM_RELEASE) {
+    SCULPT_filter_cache_free(ss);
+    SCULPT_undo_push_end();
+    SCULPT_flush_update_done(C, ob, SCULPT_UPDATE_COORDS);
+    return OPERATOR_FINISHED;
+  }
+
+  if (event->type != MOUSEMOVE) {
+    return OPERATOR_RUNNING_MODAL;
+  }
+
+  float len = event->prevclickx - event->mval[0];
+  filter_strength = filter_strength * -len * 0.001f * UI_DPI_FAC;
+
+  SCULPT_vertex_random_access_init(ss);
+
+  BKE_sculpt_update_object_for_edit(depsgraph, ob, true, true);
+
+  const int totverts = SCULPT_vertex_count_get(ss);
+  for (int i = 0; i < totverts; i++) {
+    copy_v3_v3(ss->filter_cache->cloth_sim->pos[i], SCULPT_vertex_co_get(ss, i));
+  }
+
+  SculptThreadedTaskData data = {
+      .sd = sd,
+      .ob = ob,
+      .nodes = ss->filter_cache->nodes,
+      .filter_type = filter_type,
+      .filter_strength = filter_strength,
+  };
+
+  TaskParallelSettings settings;
+  BKE_pbvh_parallel_range_settings(
+      &settings, (sd->flags & SCULPT_USE_OPENMP), ss->filter_cache->totnode);
+  BLI_task_parallel_range(
+      0, ss->filter_cache->totnode, &data, cloth_filter_apply_forces_task_cb, &settings);
+
+  /* Update and write the simulation to the nodes. */
+  cloth_brush_do_simulation_step(
+      sd, ob, ss->filter_cache->cloth_sim, ss->filter_cache->nodes, ss->filter_cache->totnode);
+
+  if (ss->deform_modifiers_active || ss->shapekey_active) {
+    SCULPT_flush_stroke_deform(sd, ob, true);
+  }
+  SCULPT_flush_update_step(C, SCULPT_UPDATE_COORDS);
+  return OPERATOR_RUNNING_MODAL;
+}
+
+static int sculpt_cloth_filter_invoke(bContext *C, wmOperator *op, const wmEvent *event)
+{
+  Object *ob = CTX_data_active_object(C);
+  Depsgraph *depsgraph = CTX_data_depsgraph_pointer(C);
+  Sculpt *sd = CTX_data_tool_settings(C)->sculpt;
+  SculptSession *ss = ob->sculpt;
+
+  /* Update the active vertex */
+  float mouse[2];
+  SculptCursorGeometryInfo sgi;
+  mouse[0] = event->mval[0];
+  mouse[1] = event->mval[1];
+  SCULPT_cursor_geometry_info_update(C, &sgi, mouse, false);
+
+  SCULPT_vertex_random_access_init(ss);
+
+  /* Needs mask data to be available as it is used when solving the constraints. */
+  BKE_sculpt_update_object_for_edit(depsgraph, ob, true, true);
+
+  SCULPT_undo_push_begin("Cloth filter");
+  SCULPT_filter_cache_init(ob, sd);
+
+  const float cloth_mass = RNA_float_get(op->ptr, "cloth_mass");
+  const float cloth_damping = RNA_float_get(op->ptr, "cloth_damping");
+  ss->filter_cache->cloth_sim = cloth_brush_simulation_create(ss, cloth_mass, cloth_damping);
+  copy_v3_v3(ss->filter_cache->cloth_sim_pinch_point, SCULPT_active_vertex_co_get(ss));
+
+  const int totverts = SCULPT_vertex_count_get(ss);
+  for (int i = 0; i < totverts; i++) {
+    copy_v3_v3(ss->filter_cache->cloth_sim->prev_pos[i], SCULPT_vertex_co_get(ss, i));
+    copy_v3_v3(ss->filter_cache->cloth_sim->init_pos[i], SCULPT_vertex_co_get(ss, i));
+  }
+
+  float origin[3] = {0.0f, 0.0f, 0.0f};
+  cloth_brush_build_nodes_constraints(sd,
+                                      ob,
+                                      ss->filter_cache->nodes,
+                                      ss->filter_cache->totnode,
+                                      ss->filter_cache->cloth_sim,
+                                      origin,
+                                      FLT_MAX);
+
+  const bool use_face_sets = RNA_boolean_get(op->ptr, "use_face_sets");
+  if (use_face_sets) {
+    ss->filter_cache->active_face_set = SCULPT_active_face_set_get(ss);
+  }
+  else {
+    ss->filter_cache->active_face_set = SCULPT_FACE_SET_NONE;
+  }
+
+  WM_event_add_modal_handler(C, op);
+  return OPERATOR_RUNNING_MODAL;
+}
+
+void SCULPT_OT_cloth_filter(struct wmOperatorType *ot)
+{
+  /* Identifiers. */
+  ot->name = "Filter cloth";
+  ot->idname = "SCULPT_OT_cloth_filter";
+  ot->description = "Applies a cloth simulation deformation to the entire mesh";
+
+  /* API callbacks. */
+  ot->invoke = sculpt_cloth_filter_invoke;
+  ot->modal = sculpt_cloth_filter_modal;
+  ot->poll = SCULPT_mode_poll;
+
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+  /* RNA. */
+  RNA_def_enum(ot->srna,
+               "type",
+               prop_cloth_filter_type,
+               CLOTH_FILTER_GRAVITY,
+               "Filter type",
+               "Operation that is going to be applied to the mesh");
+  RNA_def_float(
+      ot->srna, "strength", 1.0f, -10.0f, 10.0f, "Strength", "Filter Strength", -10.0f, 10.0f);
+  RNA_def_float(ot->srna,
+                "cloth_mass",
+                1.0f,
+                0.0f,
+                2.0f,
+                "Cloth Mass",
+                "Mass of each simulation particle",
+                0.0f,
+                1.0f);
+  RNA_def_float(ot->srna,
+                "cloth_damping",
+                0.0f,
+                0.0f,
+                1.0f,
+                "Cloth Damping",
+                "How much the applied forces are propagated through the cloth",
+                0.0f,
+                1.0f);
+  ot->prop = RNA_def_boolean(ot->srna,
+                             "use_face_sets",
+                             false,
+                             "Use Face Sets",
+                             "Apply the filter only to the Face Set under the cursor");
+}

source/blender/editors/sculpt_paint/sculpt_filter_mesh.c

@@ -121,6 +121,9 @@ void SCULPT_filter_cache_init(Object *ob, Sculpt *sd)
 
 void SCULPT_filter_cache_free(SculptSession *ss)
 {
+  if (ss->filter_cache->cloth_sim) {
+    SCULPT_cloth_simulation_free(ss->filter_cache->cloth_sim);
+  }
   MEM_SAFE_FREE(ss->filter_cache->nodes);
   MEM_SAFE_FREE(ss->filter_cache->mask_update_it);
   MEM_SAFE_FREE(ss->filter_cache->prev_mask);

source/blender/editors/sculpt_paint/sculpt_intern.h

@@ -592,6 +592,9 @@ typedef struct SculptThreadedTaskData {
   float transform_mats[8][4][4];
 
   float cloth_time_step;
+  SculptClothSimulation *cloth_sim;
+  float *cloth_sim_initial_location;
+  float cloth_sim_radius;
 
   float dirty_mask_min;
   float dirty_mask_max;
@@ -837,6 +840,10 @@ typedef struct FilterCache {
   PBVHNode **nodes;
   int totnode;
 
+  /* Cloth filter. */
+  SculptClothSimulation *cloth_sim;
+  float cloth_sim_pinch_point[3];
+
   /* mask expand iteration caches */
   int mask_update_current_it;
   int mask_update_last_it;
@@ -891,6 +898,9 @@ void SCULPT_OT_set_pivot_position(struct wmOperatorType *ot);
 /* Mesh Filter. */
 void SCULPT_OT_mesh_filter(struct wmOperatorType *ot);
 
+/* Cloth Filter. */
+void SCULPT_OT_cloth_filter(struct wmOperatorType *ot);
+
 /* Mask filter and Dirty Mask. */
 void SCULPT_OT_mask_filter(struct wmOperatorType *ot);
 void SCULPT_OT_dirty_mask(struct wmOperatorType *ot);