Point Cloud: Delete operator

Note: The point cloud bounding box is not being updated once the points are deleted.

This is a known issue with BKE_pointcloud_nomain_to_pointcloud and Hans is looking into it.

Code inspired/built based on the Delete Geometry node.

Pull Request: https://projects.blender.org/blender/blender/pulls/134622

scripts/presets/keyconfig/keymap_data/blender_default.py

@@ -5812,6 +5812,8 @@ def km_edit_point_cloud(params):
 
         ("point_cloud.duplicate_move", {"type": 'D', "value": 'PRESS', "shift": True}, None),
         *_template_items_select_actions(params, "point_cloud.select_all"),
+        ("point_cloud.delete", {"type": 'X', "value": 'PRESS'}, None),
+        ("point_cloud.delete", {"type": 'DEL', "value": 'PRESS'}, None),
         ("transform.transform", {"type": 'S', "value": 'PRESS', "alt": True},
          {"properties": [("mode", 'CURVE_SHRINKFATTEN')]}),
     ])

scripts/presets/keyconfig/keymap_data/industry_compatible_data.py

@@ -3434,6 +3434,8 @@ def km_point_cloud(params):
          "ctrl": True}, {"properties": [("action", 'DESELECT')]}),
         ("point_cloud.select_all", {"type": 'I', "value": 'PRESS',
          "ctrl": True}, {"properties": [("action", 'INVERT')]}),
+        # Delete
+        ("point_cloud.delete", {"type": 'DEL', "value": 'PRESS'}, None),
     ])
 
     return keymap

scripts/startup/bl_ui/space_view3d.py

@@ -5904,6 +5904,7 @@ class VIEW3D_MT_edit_pointcloud(Menu):
         layout.operator("point_cloud.duplicate_move")
         layout.separator()
         layout.operator("point_cloud.attribute_set")
+        layout.operator("point_cloud.delete")
         layout.template_node_operator_asset_menu_items(catalog_path=self.bl_label)
 
 

source/blender/blenkernel/BKE_pointcloud.hh

@@ -59,6 +59,13 @@ void BKE_pointcloud_nomain_to_pointcloud(PointCloud *pointcloud_src, PointCloud
 
 bool BKE_pointcloud_attribute_required(const PointCloud *pointcloud, blender::StringRef name);
 
+/**
+ * Copy data from #src to #dst, except the geometry and attributes. Typically used to
+ * copy high-level parameters when a geometry-altering operation creates a new point cloud
+ * data-block.
+ */
+void pointcloud_copy_parameters(const PointCloud &src, PointCloud &dst);
+
 /* Dependency Graph */
 
 PointCloud *BKE_pointcloud_copy_for_eval(const PointCloud *pointcloud_src);

source/blender/blenkernel/intern/pointcloud.cc

@@ -369,6 +369,15 @@ bool BKE_pointcloud_attribute_required(const PointCloud * /*pointcloud*/,
   return name == POINTCLOUD_ATTR_POSITION;
 }
 
+void pointcloud_copy_parameters(const PointCloud &src, PointCloud &dst)
+{
+  dst.flag = src.flag;
+  MEM_SAFE_FREE(dst.mat);
+  dst.mat = static_cast<Material **>(MEM_malloc_arrayN(src.totcol, sizeof(Material *), __func__));
+  dst.totcol = src.totcol;
+  MutableSpan(dst.mat, dst.totcol).copy_from(Span(src.mat, src.totcol));
+}
+
 /* Dependency Graph */
 
 PointCloud *BKE_pointcloud_copy_for_eval(const PointCloud *pointcloud_src)

source/blender/blenlib/BLI_index_mask.hh

@@ -199,6 +199,7 @@ class IndexMask : private IndexMaskData {
   /** Construct a mask from the true indices. */
   static IndexMask from_bools(Span<bool> bools, IndexMaskMemory &memory);
   static IndexMask from_bools(const VArray<bool> &bools, IndexMaskMemory &memory);
+  static IndexMask from_bools_inverse(const VArray<bool> &bools, IndexMaskMemory &memory);
   /** Construct a mask from the true indices, but limited by the indices in #universe. */
   static IndexMask from_bools(const IndexMask &universe,
                               Span<bool> bools,
@@ -209,6 +210,9 @@ class IndexMask : private IndexMaskData {
   static IndexMask from_bools(const IndexMask &universe,
                               const VArray<bool> &bools,
                               IndexMaskMemory &memory);
+  static IndexMask from_bools_inverse(const IndexMask &universe,
+                                      const VArray<bool> &bools,
+                                      IndexMaskMemory &memory);
   /** Construct a mask from the ranges referenced by the offset indices. */
   template<typename T>
   static IndexMask from_ranges(OffsetIndices<T> offsets,

source/blender/blenlib/intern/index_mask.cc

@@ -586,6 +586,11 @@ IndexMask IndexMask::from_bools(const VArray<bool> &bools, IndexMaskMemory &memo
   return IndexMask::from_bools(bools.index_range(), bools, memory);
 }
 
+IndexMask IndexMask::from_bools_inverse(const VArray<bool> &bools, IndexMaskMemory &memory)
+{
+  return IndexMask::from_bools_inverse(bools.index_range(), bools, memory);
+}
+
 IndexMask IndexMask::from_bools(const IndexMask &universe,
                                 Span<bool> bools,
                                 IndexMaskMemory &memory)
@@ -640,6 +645,22 @@ IndexMask IndexMask::from_bools(const IndexMask &universe,
       universe, GrainSize(512), memory, [&](const int64_t index) { return bools[index]; });
 }
 
+IndexMask IndexMask::from_bools_inverse(const IndexMask &universe,
+                                        const VArray<bool> &bools,
+                                        IndexMaskMemory &memory)
+{
+  const CommonVArrayInfo info = bools.common_info();
+  if (info.type == CommonVArrayInfo::Type::Single) {
+    return *static_cast<const bool *>(info.data) ? IndexMask() : universe;
+  }
+  if (info.type == CommonVArrayInfo::Type::Span) {
+    const Span<bool> span(static_cast<const bool *>(info.data), bools.size());
+    return IndexMask::from_bools_inverse(universe, span, memory);
+  }
+  return IndexMask::from_predicate(
+      universe, GrainSize(512), memory, [&](const int64_t index) { return !bools[index]; });
+}
+
 template<typename T>
 IndexMask IndexMask::from_ranges(OffsetIndices<T> offsets,
                                  const IndexMask &mask,

source/blender/editors/include/ED_point_cloud.hh

@@ -114,6 +114,18 @@ IndexMask retrieve_selected_points(const PointCloud &pointcloud, IndexMaskMemory
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name Editing
+ * \{ */
+
+/**
+ * Remove selected points based on the ".selection" attribute.
+ * \returns true if any point was removed.
+ */
+bool remove_selection(PointCloud &point_cloud);
+
+/** \} */
+
 /* -------------------------------------------------------------------- */
 /** \name Poll Functions
  * \{ */

source/blender/editors/point_cloud/CMakeLists.txt

@@ -16,6 +16,7 @@ set(INC_SYS
 set(SRC
   intern/attribute_set.cc
   intern/duplicate.cc
+  intern/point_cloud_edit.cc
   intern/point_cloud_ops.cc
   intern/point_cloud_selection.cc
   intern/point_cloud_undo.cc

source/blender/editors/point_cloud/intern/point_cloud_edit.cc

@@ -0,0 +1,39 @@
+/* SPDX-FileCopyrightText: 2025 Blender Authors
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup edpointcloud
+ */
+
+#include "BKE_attribute.hh"
+#include "BKE_pointcloud.hh"
+
+#include "DNA_node_types.h"
+
+#include "ED_point_cloud.hh"
+
+namespace blender::ed::point_cloud {
+
+bool remove_selection(PointCloud &point_cloud)
+{
+  const bke::AttributeAccessor attributes = point_cloud.attributes();
+  const VArray<bool> selection = *attributes.lookup_or_default<bool>(
+      ".selection", bke::AttrDomain::Point, true);
+  const int domain_size_orig = point_cloud.totpoint;
+  IndexMaskMemory memory;
+  const IndexMask mask = IndexMask::from_bools_inverse(selection, memory);
+
+  PointCloud *point_cloud_new = BKE_pointcloud_new_nomain(mask.size());
+  bke::gather_attributes(attributes,
+                         bke::AttrDomain::Point,
+                         bke::AttrDomain::Point,
+                         {},
+                         mask,
+                         point_cloud_new->attributes_for_write());
+  pointcloud_copy_parameters(point_cloud, *point_cloud_new);
+  BKE_pointcloud_nomain_to_pointcloud(point_cloud_new, &point_cloud);
+  return point_cloud.totpoint != domain_size_orig;
+}
+
+}  // namespace blender::ed::point_cloud

source/blender/editors/point_cloud/intern/point_cloud_ops.cc

@@ -140,9 +140,38 @@ static void POINT_CLOUD_OT_select_all(wmOperatorType *ot)
   WM_operator_properties_select_all(ot);
 }
 
+namespace point_cloud_delete {
+
+static int delete_exec(bContext *C, wmOperator * /*op*/)
+{
+  for (PointCloud *point_cloud : get_unique_editable_point_clouds(*C)) {
+    if (remove_selection(*point_cloud)) {
+      DEG_id_tag_update(&point_cloud->id, ID_RECALC_GEOMETRY);
+      WM_event_add_notifier(C, NC_GEOM | ND_DATA, &point_cloud);
+    }
+  }
+
+  return OPERATOR_FINISHED;
+}
+
+}  // namespace point_cloud_delete
+
+static void POINT_CLOUD_OT_delete(wmOperatorType *ot)
+{
+  ot->name = "Delete";
+  ot->idname = __func__;
+  ot->description = "Remove selected points";
+
+  ot->exec = point_cloud_delete::delete_exec;
+  ot->poll = editable_point_cloud_in_edit_mode_poll;
+
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+}
+
 void operatortypes_point_cloud()
 {
   WM_operatortype_append(POINT_CLOUD_OT_attribute_set);
+  WM_operatortype_append(POINT_CLOUD_OT_delete);
   WM_operatortype_append(POINT_CLOUD_OT_duplicate);
   WM_operatortype_append(POINT_CLOUD_OT_select_all);
 }