Geometry Nodes: Extrude Mesh Node

This patch introduces an extrude node with three modes. The vertex mode
is quite simple, and just attaches new edges to the selected vertices.
The edge mode attaches new faces to the selected edges. The faces mode
extrudes patches of selected faces, or each selected face individually,
depending on the "Individual" boolean input.

The default value of the "Offset" input is the mesh's normals, which
can be scaled with the "Offset Scale" input.

**Attribute Propagation**
Attributes are transferred to the new elements with specific rules.
Attributes will never change domains for interpolations. Generally
boolean attributes are propagated with "or", meaning any connected
"true" value that is mixed in for other types will cause the new value
to be "true" as well. The `"id"` attribute does not have any special
handling currently.

Vertex Mode
 - Vertex: Copied values of selected vertices.
 - Edge: Averaged values of selected edges. For booleans, edges are
   selected if any connected edges are selected.
Edge Mode
 - Vertex: Copied values of extruded vertices.
 - Connecting edges (vertical): Average values of connected extruded
   edges. For booleans, the edges are selected if any connected
   extruded edges are selected.
 - Duplicate edges: Copied values of selected edges.
 - Face: Averaged values of all faces connected to the selected edge.
   For booleans, faces are selected if any connected original faces
   are selected.
 - Corner: Averaged values of corresponding corners in all faces
   connected to selected edges. For booleans, corners are selected
   if one of those corners are selected.
Face Mode
 - Vertex: Copied values of extruded vertices.
 - Connecting edges (vertical): Average values of connected selected
   edges, not including the edges "on top" of extruded regions.
   For booleans, edges are selected when any connected extruded edges
   were selected.
 - Duplicate edges: Copied values of extruded edges.
 - Face: Copied values of the corresponding selected faces.
 - Corner: Copied values of corresponding corners in selected faces.
Individual Face Mode
 - Vertex: Copied values of extruded vertices.
 - Connecting edges (vertical): Average values of the two neighboring
   edges on each extruded face. For booleans, edges are selected
   when at least one neighbor on the extruded face was selected.
 - Duplicate edges: Copied values of extruded edges.
 - Face: Copied values of the corresponding selected faces.
 - Corner: Copied values of corresponding corners in selected faces.

**Differences from edit mode**
In face mode (non-individual), the behavior can be different than the
extrude tools in edit mode-- this node doesn't handle keeping the back-
faces around in the cases that the edit mode tools do. The planned
"Solidify" node will handle that use case instead. Keeping this node
simpler and faster is preferable at this point, especially because that
sort of "smart" behavior is not that predictable and makes less sense
in a procedural context.

In the future, an "Even Offset" option could be added to this node
hopefully fairly simply. For now it is left out in order to keep
the patch simpler.

**Implementation**
For the implementation, the `Mesh` data structure is used directly
rather than converting to `BMesh` and back like D12224. This optimizes
for large extrusion operations rather than many sequential extrusions.
While this is potentially more verbose, it has some important benefits:
First, there is no conversion to and from `BMesh`. The code only has
to fill arrays and it can do that all at once, making each component of
the algorithm much easier to optimize. It also makes the attribute
interpolation more explicit, and likely faster. Only limited topology
maps must be created in most cases.

While there are some necessary loops and allocations with the size of
the entire mesh, I tried to keep everything I could on the order of the
size of the selection rather than the size of the mesh. In that respect,
the individual faces mode is the best, since there is no topology
information necessary, and the amount of work just depends on the size
of the selection.

Modifying an existing mesh instead of generating a new one was a bit
of a toss-up, but has a few potential benefits:
 - Avoids manually copying over attribute data for original elements.
 - Avoids some overhead of creating a new mesh.
 - Can potentially take advantage of future ammortized mesh growth.
This could be changed easily if it turns out to be the wrong choice.

Differential Revision: https://developer.blender.org/D13709

12 files changed, 1466 insertions, 2 deletions

diff --git a/release/scripts/startup/nodeitems_builtins.py b/release/scripts/startup/nodeitems_builtins.py
index b8099127a55..92e5eb91da6 100644
--- a/release/scripts/startup/nodeitems_builtins.py
+++ b/release/scripts/startup/nodeitems_builtins.py
@@ -142,6 +142,7 @@ def mesh_node_items(context):
         yield NodeItemCustom(draw=lambda self, layout, context: layout.separator())
 
     yield NodeItem("GeometryNodeDualMesh")
+    yield NodeItem("GeometryNodeExtrudeMesh")
     yield NodeItem("GeometryNodeFlipFaces")
     yield NodeItem("GeometryNodeMeshBoolean")
     yield NodeItem("GeometryNodeMeshToCurve")
diff --git a/source/blender/blenkernel/BKE_attribute_math.hh b/source/blender/blenkernel/BKE_attribute_math.hh
index a7bdca06790..90f349125c9 100644
--- a/source/blender/blenkernel/BKE_attribute_math.hh
+++ b/source/blender/blenkernel/BKE_attribute_math.hh
@@ -231,6 +231,43 @@ template<typename T> class SimpleMixer {
 };
 
 /**
+ * Mixes together booleans with "or" while fitting the same interface as the other
+ * mixers in order to be simpler to use. This mixing method has a few benefits:
+ *  - An "average" for selections is relatively meaningless.
+ *  - Predictable selection propagation is very super important.
+ *  - It's generally  easier to remove an element from a selection that is slightly too large than
+ *    the opposite.
+ */
+class BooleanPropagationMixer {
+ private:
+  MutableSpan<bool> buffer_;
+
+ public:
+  /**
+   * \param buffer: Span where the interpolated values should be stored.
+   */
+  BooleanPropagationMixer(MutableSpan<bool> buffer) : buffer_(buffer)
+  {
+    buffer_.fill(false);
+  }
+
+  /**
+   * Mix a #value into the element with the given #index.
+   */
+  void mix_in(const int64_t index, const bool value, [[maybe_unused]] const float weight = 1.0f)
+  {
+    buffer_[index] |= value;
+  }
+
+  /**
+   * Does not do anything, since the mixing is trivial.
+   */
+  void finalize()
+  {
+  }
+};
+
+/**
  * This mixer accumulates values in a type that is different from the one that is mixed.
  * Some types cannot encode the floating point weights in their values (e.g. int and bool).
  */
@@ -291,7 +328,7 @@ class ColorGeometryMixer {
 };
 
 template<typename T> struct DefaultMixerStruct {
-  /* Use void by default. This can be check for in `if constexpr` statements. */
+  /* Use void by default. This can be checked for in `if constexpr` statements. */
   using type = void;
 };
 template<> struct DefaultMixerStruct<float> {
@@ -327,6 +364,23 @@ template<> struct DefaultMixerStruct<bool> {
   using type = SimpleMixerWithAccumulationType<bool, float, float_to_bool>;
 };
 
+template<typename T> struct DefaultPropatationMixerStruct {
+  /* Use void by default. This can be checked for in `if constexpr` statements. */
+  using type = typename DefaultMixerStruct<T>::type;
+};
+
+template<> struct DefaultPropatationMixerStruct<bool> {
+  using type = BooleanPropagationMixer;
+};
+
+/**
+ * This mixer is meant for propagating attributes when creating new geometry. A key difference
+ * with the default mixer is that booleans are mixed with "or" instead of "at least half"
+ * (the default mixing for booleans).
+ */
+template<typename T>
+using DefaultPropatationMixer = typename DefaultPropatationMixerStruct<T>::type;
+
 /* Utility to get a good default mixer for a given type. This is `void` when there is no default
  * mixer for the given type. */
 template<typename T> using DefaultMixer = typename DefaultMixerStruct<T>::type;
diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index 3b952204755..2f9034f6438 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -1632,6 +1632,7 @@ int ntreeTexExecTree(struct bNodeTree *ntree,
 #define GEO_NODE_CURVE_PRIMITIVE_ARC 1149
 #define GEO_NODE_FLIP_FACES 1150
 #define GEO_NODE_SCALE_ELEMENTS 1151
+#define GEO_NODE_EXTRUDE_MESH 1152
 
 /** \} */
 
diff --git a/source/blender/blenkernel/intern/customdata.cc b/source/blender/blenkernel/intern/customdata.cc
index e1bc025efd2..5e3beab9b72 100644
--- a/source/blender/blenkernel/intern/customdata.cc
+++ b/source/blender/blenkernel/intern/customdata.cc
@@ -2209,7 +2209,9 @@ void CustomData_realloc(CustomData *data, int totelem)
       continue;
     }
     typeInfo = layerType_getInfo(layer->type);
-    layer->data = MEM_reallocN(layer->data, (size_t)totelem * typeInfo->size);
+    /* Use calloc to avoid the need to manually initialize new data in layers.
+     * Useful for types like #MDeformVert which contain a pointer. */
+    layer->data = MEM_recallocN(layer->data, (size_t)totelem * typeInfo->size);
   }
 }
 
diff --git a/source/blender/blenkernel/intern/node.cc b/source/blender/blenkernel/intern/node.cc
index 1acd4248639..8baffff9ecf 100644
--- a/source/blender/blenkernel/intern/node.cc
+++ b/source/blender/blenkernel/intern/node.cc
@@ -4768,6 +4768,7 @@ static void registerGeometryNodes()
   register_node_type_geo_distribute_points_on_faces();
   register_node_type_geo_dual_mesh();
   register_node_type_geo_edge_split();
+  register_node_type_geo_extrude_mesh();
   register_node_type_geo_field_at_index();
   register_node_type_geo_flip_faces();
   register_node_type_geo_geometry_to_instance();
diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index 10058204e88..cc2f7ce615a 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -1385,6 +1385,11 @@ typedef struct NodeGeometryPointTranslate {
   uint8_t input_type;
 } NodeGeometryPointTranslate;
 
+typedef struct NodeGeometryExtrudeMesh {
+  /* GeometryNodeExtrudeMeshMode */
+  uint8_t mode;
+} NodeGeometryExtrudeMesh;
+
 typedef struct NodeGeometryObjectInfo {
   /* GeometryNodeTransformSpace. */
   uint8_t transform_space;
@@ -2155,6 +2160,12 @@ typedef enum GeometryNodeDistributePointsOnFacesMode {
   GEO_NODE_POINT_DISTRIBUTE_POINTS_ON_FACES_POISSON = 1,
 } GeometryNodeDistributePointsOnFacesMode;
 
+typedef enum GeometryNodeExtrudeMeshMode {
+  GEO_NODE_EXTRUDE_MESH_VERTICES = 0,
+  GEO_NODE_EXTRUDE_MESH_EDGES = 1,
+  GEO_NODE_EXTRUDE_MESH_FACES = 2,
+} GeometryNodeExtrudeMeshMode;
+
 typedef enum GeometryNodeRotatePointsType {
   GEO_NODE_POINT_ROTATE_TYPE_EULER = 0,
   GEO_NODE_POINT_ROTATE_TYPE_AXIS_ANGLE = 1,
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index c506c35e281..4192a9975be 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -9894,6 +9894,27 @@ static void def_geo_point_distribute(StructRNA *srna)
   RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update");
 }
 
+static void def_geo_extrude_mesh(StructRNA *srna)
+{
+  PropertyRNA *prop;
+
+  static const EnumPropertyItem mode_items[] = {
+      {GEO_NODE_EXTRUDE_MESH_VERTICES, "VERTICES", 0, "Vertices", ""},
+      {GEO_NODE_EXTRUDE_MESH_EDGES, "EDGES", 0, "Edges", ""},
+      {GEO_NODE_EXTRUDE_MESH_FACES, "FACES", 0, "Faces", ""},
+      {0, NULL, 0, NULL, NULL},
+  };
+
+  RNA_def_struct_sdna_from(srna, "NodeGeometryExtrudeMesh", "storage");
+
+  prop = RNA_def_property(srna, "mode", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_sdna(prop, NULL, "mode");
+  RNA_def_property_enum_items(prop, mode_items);
+  RNA_def_property_enum_default(prop, GEO_NODE_EXTRUDE_MESH_FACES);
+  RNA_def_property_ui_text(prop, "Mode", "");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+}
+
 static void def_geo_distribute_points_on_faces(StructRNA *srna)
 {
   PropertyRNA *prop;
diff --git a/source/blender/modifiers/intern/MOD_nodes_evaluator.cc b/source/blender/modifiers/intern/MOD_nodes_evaluator.cc
index 21ad8dd5bbc..5362d86a87f 100644
--- a/source/blender/modifiers/intern/MOD_nodes_evaluator.cc
+++ b/source/blender/modifiers/intern/MOD_nodes_evaluator.cc
@@ -381,6 +381,11 @@ static bool get_implicit_socket_input(const SocketRef &socket, void *r_value)
         new (r_value) ValueOrField<float3>(bke::AttributeFieldInput::Create<float3>(side));
         return true;
       }
+      if (bnode.type == GEO_NODE_EXTRUDE_MESH) {
+        new (r_value)
+            ValueOrField<float3>(Field<float3>(std::make_shared<bke::NormalFieldInput>()));
+        return true;
+      }
       new (r_value) ValueOrField<float3>(bke::AttributeFieldInput::Create<float3>("position"));
       return true;
     }
diff --git a/source/blender/nodes/NOD_geometry.h b/source/blender/nodes/NOD_geometry.h
index 9c9e3876662..e5c005f8c95 100644
--- a/source/blender/nodes/NOD_geometry.h
+++ b/source/blender/nodes/NOD_geometry.h
@@ -99,6 +99,7 @@ void register_node_type_geo_delete_geometry(void);
 void register_node_type_geo_distribute_points_on_faces(void);
 void register_node_type_geo_dual_mesh(void);
 void register_node_type_geo_edge_split(void);
+void register_node_type_geo_extrude_mesh(void);
 void register_node_type_geo_field_at_index(void);
 void register_node_type_geo_flip_faces(void);
 void register_node_type_geo_geometry_to_instance(void);
diff --git a/source/blender/nodes/NOD_static_types.h b/source/blender/nodes/NOD_static_types.h
index 06a1cf90fca..66a2d3720ca 100644
--- a/source/blender/nodes/NOD_static_types.h
+++ b/source/blender/nodes/NOD_static_types.h
@@ -352,6 +352,7 @@ DefNode(GeometryNode, GEO_NODE_DELETE_GEOMETRY, def_geo_delete_geometry, "DELETE
 DefNode(GeometryNode, GEO_NODE_DISTRIBUTE_POINTS_ON_FACES, def_geo_distribute_points_on_faces, "DISTRIBUTE_POINTS_ON_FACES", DistributePointsOnFaces, "Distribute Points on Faces", "")
 DefNode(GeometryNode, GEO_NODE_ACCUMULATE_FIELD, def_geo_accumulate_field, "ACCUMULATE_FIELD", AccumulateField, "Accumulate Field", "")
 DefNode(GeometryNode, GEO_NODE_DUAL_MESH, 0, "DUAL_MESH", DualMesh, "Dual Mesh", "")
+DefNode(GeometryNode, GEO_NODE_EXTRUDE_MESH, def_geo_extrude_mesh, "EXTRUDE_MESH", ExtrudeMesh, "Extrude Mesh", "")
 DefNode(GeometryNode, GEO_NODE_FIELD_AT_INDEX, def_geo_field_at_index, "FIELD_AT_INDEX", FieldAtIndex, "Field at Index", "")
 DefNode(GeometryNode, GEO_NODE_FILL_CURVE, def_geo_curve_fill, "FILL_CURVE", FillCurve, "Fill Curve", "")
 DefNode(GeometryNode, GEO_NODE_FILLET_CURVE, def_geo_curve_fillet, "FILLET_CURVE", FilletCurve, "Fillet Curve", "")
diff --git a/source/blender/nodes/geometry/CMakeLists.txt b/source/blender/nodes/geometry/CMakeLists.txt
index 37b43c26a86..0e5f90b58bf 100644
--- a/source/blender/nodes/geometry/CMakeLists.txt
+++ b/source/blender/nodes/geometry/CMakeLists.txt
@@ -117,6 +117,7 @@ set(SRC
   nodes/node_geo_distribute_points_on_faces.cc
   nodes/node_geo_dual_mesh.cc
   nodes/node_geo_edge_split.cc
+  nodes/node_geo_extrude_mesh.cc
   nodes/node_geo_field_at_index.cc
   nodes/node_geo_flip_faces.cc
   nodes/node_geo_geometry_to_instance.cc
diff --git a/source/blender/nodes/geometry/nodes/node_geo_extrude_mesh.cc b/source/blender/nodes/geometry/nodes/node_geo_extrude_mesh.cc
new file mode 100644
index 00000000000..1d1c5bd2285
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_extrude_mesh.cc
@@ -0,0 +1,1365 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "BLI_disjoint_set.hh"
+#include "BLI_task.hh"
+#include "BLI_vector_set.hh"
+
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+
+#include "BKE_attribute_math.hh"
+#include "BKE_mesh.h"
+#include "BKE_mesh_runtime.h"
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "node_geometry_util.hh"
+
+namespace blender::nodes::node_geo_extrude_mesh_cc {
+
+NODE_STORAGE_FUNCS(NodeGeometryExtrudeMesh)
+
+static void node_declare(NodeDeclarationBuilder &b)
+{
+  b.add_input<decl::Geometry>("Mesh").supported_type(GEO_COMPONENT_TYPE_MESH);
+  b.add_input<decl::Bool>(N_("Selection")).default_value(true).supports_field().hide_value();
+  b.add_input<decl::Vector>(N_("Offset")).subtype(PROP_TRANSLATION).implicit_field().hide_value();
+  b.add_input<decl::Float>(N_("Offset Scale")).default_value(1.0f).min(0.0f).supports_field();
+  b.add_input<decl::Bool>(N_("Individual")).default_value(true);
+  b.add_output<decl::Geometry>("Mesh");
+  b.add_output<decl::Bool>(N_("Top")).field_source();
+  b.add_output<decl::Bool>(N_("Side")).field_source();
+}
+
+static void node_layout(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
+{
+  uiLayoutSetPropSep(layout, true);
+  uiLayoutSetPropDecorate(layout, false);
+  uiItemR(layout, ptr, "mode", 0, "", ICON_NONE);
+}
+
+static void node_init(bNodeTree *UNUSED(tree), bNode *node)
+{
+  NodeGeometryExtrudeMesh *data = MEM_cnew<NodeGeometryExtrudeMesh>(__func__);
+  data->mode = GEO_NODE_EXTRUDE_MESH_FACES;
+  node->storage = data;
+}
+
+static void node_update(bNodeTree *ntree, bNode *node)
+{
+  const NodeGeometryExtrudeMesh &storage = node_storage(*node);
+  const GeometryNodeExtrudeMeshMode mode = static_cast<GeometryNodeExtrudeMeshMode>(storage.mode);
+
+  bNodeSocket *individual_socket = (bNodeSocket *)node->inputs.last;
+
+  nodeSetSocketAvailability(ntree, individual_socket, mode == GEO_NODE_EXTRUDE_MESH_FACES);
+}
+
+struct AttributeOutputs {
+  StrongAnonymousAttributeID top_id;
+  StrongAnonymousAttributeID side_id;
+};
+
+static void save_selection_as_attribute(MeshComponent &component,
+                                        const AnonymousAttributeID *id,
+                                        const AttributeDomain domain,
+                                        const IndexMask selection)
+{
+  BLI_assert(!component.attribute_exists(id));
+
+  OutputAttribute_Typed<bool> attribute = component.attribute_try_get_for_output_only<bool>(
+      id, domain);
+  /* Rely on the new attribute being zeroed by default. */
+  BLI_assert(!attribute.as_span().as_span().contains(true));
+
+  if (selection.is_range()) {
+    attribute.as_span().slice(selection.as_range()).fill(true);
+  }
+  else {
+    attribute.as_span().fill_indices(selection, true);
+  }
+
+  attribute.save();
+}
+
+static MutableSpan<MVert> mesh_verts(Mesh &mesh)
+{
+  return {mesh.mvert, mesh.totvert};
+}
+static MutableSpan<MEdge> mesh_edges(Mesh &mesh)
+{
+  return {mesh.medge, mesh.totedge};
+}
+static Span<MPoly> mesh_polys(const Mesh &mesh)
+{
+  return {mesh.mpoly, mesh.totpoly};
+}
+static MutableSpan<MPoly> mesh_polys(Mesh &mesh)
+{
+  return {mesh.mpoly, mesh.totpoly};
+}
+static Span<MLoop> mesh_loops(const Mesh &mesh)
+{
+  return {mesh.mloop, mesh.totloop};
+}
+static MutableSpan<MLoop> mesh_loops(Mesh &mesh)
+{
+  return {mesh.mloop, mesh.totloop};
+}
+
+/**
+ * \note: Some areas in this file rely on the new sections of attributes from #CustomData_realloc
+ * to be zeroed.
+ */
+static void expand_mesh(Mesh &mesh,
+                        const int vert_expand,
+                        const int edge_expand,
+                        const int poly_expand,
+                        const int loop_expand)
+{
+  if (vert_expand != 0) {
+    CustomData_duplicate_referenced_layers(&mesh.vdata, mesh.totvert);
+    mesh.totvert += vert_expand;
+    CustomData_realloc(&mesh.vdata, mesh.totvert);
+  }
+  else {
+    /* Even when the number of vertices is not changed, the mesh can still be deformed. */
+    CustomData_duplicate_referenced_layer(&mesh.vdata, CD_MVERT, mesh.totvert);
+  }
+  if (edge_expand != 0) {
+    CustomData_duplicate_referenced_layers(&mesh.edata, mesh.totedge);
+    mesh.totedge += edge_expand;
+    CustomData_realloc(&mesh.edata, mesh.totedge);
+  }
+  if (poly_expand != 0) {
+    CustomData_duplicate_referenced_layers(&mesh.pdata, mesh.totpoly);
+    mesh.totpoly += poly_expand;
+    CustomData_realloc(&mesh.pdata, mesh.totpoly);
+  }
+  if (loop_expand != 0) {
+    CustomData_duplicate_referenced_layers(&mesh.ldata, mesh.totloop);
+    mesh.totloop += loop_expand;
+    CustomData_realloc(&mesh.ldata, mesh.totloop);
+  }
+  BKE_mesh_update_customdata_pointers(&mesh, false);
+}
+
+static MEdge new_edge(const int v1, const int v2)
+{
+  MEdge edge;
+  edge.v1 = v1;
+  edge.v2 = v2;
+  edge.flag = (ME_EDGEDRAW | ME_EDGERENDER);
+  return edge;
+}
+
+static MEdge new_loose_edge(const int v1, const int v2)
+{
+  MEdge edge;
+  edge.v1 = v1;
+  edge.v2 = v2;
+  edge.flag = ME_LOOSEEDGE;
+  return edge;
+}
+
+static MPoly new_poly(const int loopstart, const int totloop)
+{
+  MPoly poly;
+  poly.loopstart = loopstart;
+  poly.totloop = totloop;
+  poly.flag = 0;
+  return poly;
+}
+
+template<typename T> void copy_with_indices(MutableSpan<T> dst, Span<T> src, Span<int> indices)
+{
+  BLI_assert(dst.size() == indices.size());
+  for (const int i : dst.index_range()) {
+    dst[i] = src[indices[i]];
+  }
+}
+
+template<typename T> void copy_with_mask(MutableSpan<T> dst, Span<T> src, IndexMask mask)
+{
+  BLI_assert(dst.size() == mask.size());
+  threading::parallel_for(mask.index_range(), 512, [&](const IndexRange range) {
+    for (const int i : range) {
+      dst[i] = src[mask[i]];
+    }
+  });
+}
+
+/**
+ * \param get_mix_indices_fn: Returns a Span of indices of the source points to mix for every
+ * result point.
+ */
+template<typename T, typename GetMixIndicesFn>
+void copy_with_mixing(MutableSpan<T> dst, Span<T> src, GetMixIndicesFn get_mix_indices_fn)
+{
+  threading::parallel_for(dst.index_range(), 512, [&](const IndexRange range) {
+    attribute_math::DefaultPropatationMixer<T> mixer{dst.slice(range)};
+    for (const int i_dst : IndexRange(range.size())) {
+      for (const int i_src : get_mix_indices_fn(range[i_dst])) {
+        mixer.mix_in(i_dst, src[i_src]);
+      }
+    }
+    mixer.finalize();
+  });
+}
+
+static Array<Vector<int>> create_vert_to_edge_map(const int vert_size,
+                                                  Span<MEdge> edges,
+                                                  const int vert_offset = 0)
+{
+  Array<Vector<int>> vert_to_edge_map(vert_size);
+  for (const int i : edges.index_range()) {
+    vert_to_edge_map[edges[i].v1 - vert_offset].append(i);
+    vert_to_edge_map[edges[i].v2 - vert_offset].append(i);
+  }
+  return vert_to_edge_map;
+}
+
+static void extrude_mesh_vertices(MeshComponent &component,
+                                  const Field<bool> &selection_field,
+                                  const Field<float3> &offset_field,
+                                  const AttributeOutputs &attribute_outputs)
+{
+  Mesh &mesh = *component.get_for_write();
+  const int orig_vert_size = mesh.totvert;
+  const int orig_edge_size = mesh.totedge;
+
+  GeometryComponentFieldContext context{component, ATTR_DOMAIN_POINT};
+  FieldEvaluator evaluator{context, mesh.totvert};
+  evaluator.add(offset_field);
+  evaluator.set_selection(selection_field);
+  evaluator.evaluate();
+  const IndexMask selection = evaluator.get_evaluated_selection_as_mask();
+  const VArray<float3> offsets = evaluator.get_evaluated<float3>(0);
+
+  /* This allows parallelizing attribute mixing for new edges. */
+  Array<Vector<int>> vert_to_edge_map = create_vert_to_edge_map(orig_vert_size, mesh_edges(mesh));
+
+  expand_mesh(mesh, selection.size(), selection.size(), 0, 0);
+
+  const IndexRange new_vert_range{orig_vert_size, selection.size()};
+  const IndexRange new_edge_range{orig_edge_size, selection.size()};
+
+  MutableSpan<MVert> new_verts = mesh_verts(mesh).slice(new_vert_range);
+  MutableSpan<MEdge> new_edges = mesh_edges(mesh).slice(new_edge_range);
+
+  for (const int i_selection : selection.index_range()) {
+    new_edges[i_selection] = new_loose_edge(selection[i_selection], new_vert_range[i_selection]);
+  }
+
+  component.attribute_foreach([&](const AttributeIDRef &id, const AttributeMetaData meta_data) {
+    if (!ELEM(meta_data.domain, ATTR_DOMAIN_POINT, ATTR_DOMAIN_EDGE)) {
+      return true;
+    }
+    OutputAttribute attribute = component.attribute_try_get_for_output(
+        id, meta_data.domain, meta_data.data_type);
+    attribute_math::convert_to_static_type(meta_data.data_type, [&](auto dummy) {
+      using T = decltype(dummy);
+      MutableSpan<T> data = attribute.as_span().typed<T>();
+      switch (attribute.domain()) {
+        case ATTR_DOMAIN_POINT: {
+          /* New vertices copy the attribute values from their source vertex. */
+          copy_with_mask(data.slice(new_vert_range), data.as_span(), selection);
+          break;
+        }
+        case ATTR_DOMAIN_EDGE: {
+          /* New edge values are mixed from of all the edges connected to the source vertex. */
+          copy_with_mixing(data.slice(new_edge_range), data.as_span(), [&](const int i) {
+            return vert_to_edge_map[selection[i]].as_span();
+          });
+          break;
+        }
+        default:
+          BLI_assert_unreachable();
+      }
+    });
+
+    attribute.save();
+    return true;
+  });
+
+  devirtualize_varray(offsets, [&](const auto offsets) {
+    threading::parallel_for(selection.index_range(), 1024, [&](const IndexRange range) {
+      for (const int i : range) {
+        const float3 offset = offsets[selection[i]];
+        add_v3_v3(new_verts[i].co, offset);
+      }
+    });
+  });
+
+  if (attribute_outputs.top_id) {
+    save_selection_as_attribute(
+        component, attribute_outputs.top_id.get(), ATTR_DOMAIN_POINT, new_vert_range);
+  }
+  if (attribute_outputs.side_id) {
+    save_selection_as_attribute(
+        component, attribute_outputs.side_id.get(), ATTR_DOMAIN_EDGE, new_edge_range);
+  }
+
+  BKE_mesh_runtime_clear_cache(&mesh);
+  BKE_mesh_normals_tag_dirty(&mesh);
+}
+
+static Array<Vector<int, 2>> mesh_calculate_polys_of_edge(const Mesh &mesh)
+{
+  Span<MPoly> polys = mesh_polys(mesh);
+  Span<MLoop> loops = mesh_loops(mesh);
+  Array<Vector<int, 2>> polys_of_edge(mesh.totedge);
+
+  for (const int i_poly : polys.index_range()) {
+    const MPoly &poly = polys[i_poly];
+    for (const MLoop &loop : loops.slice(poly.loopstart, poly.totloop)) {
+      polys_of_edge[loop.e].append(i_poly);
+    }
+  }
+
+  return polys_of_edge;
+}
+
+static void fill_quad_consistent_direction(Span<MLoop> other_poly_loops,
+                                           MutableSpan<MLoop> new_loops,
+                                           const int vert_connected_to_poly_1,
+                                           const int vert_connected_to_poly_2,
+                                           const int vert_across_from_poly_1,
+                                           const int vert_across_from_poly_2,
+                                           const int edge_connected_to_poly,
+                                           const int connecting_edge_1,
+                                           const int edge_across_from_poly,
+                                           const int connecting_edge_2)
+{
+  /* Find the loop on the polygon connected to the new quad that uses the duplicate edge. */
+  bool start_with_connecting_edge = true;
+  for (const MLoop &loop : other_poly_loops) {
+    if (loop.e == edge_connected_to_poly) {
+      start_with_connecting_edge = loop.v == vert_connected_to_poly_1;
+      break;
+    }
+  }
+  if (start_with_connecting_edge) {
+    new_loops[0].v = vert_connected_to_poly_1;
+    new_loops[0].e = connecting_edge_1;
+    new_loops[1].v = vert_across_from_poly_1;
+    new_loops[1].e = edge_across_from_poly;
+    new_loops[2].v = vert_across_from_poly_2;
+    new_loops[2].e = connecting_edge_2;
+    new_loops[3].v = vert_connected_to_poly_2;
+    new_loops[3].e = edge_connected_to_poly;
+  }
+  else {
+    new_loops[0].v = vert_connected_to_poly_1;
+    new_loops[0].e = edge_connected_to_poly;
+    new_loops[1].v = vert_connected_to_poly_2;
+    new_loops[1].e = connecting_edge_2;
+    new_loops[2].v = vert_across_from_poly_2;
+    new_loops[2].e = edge_across_from_poly;
+    new_loops[3].v = vert_across_from_poly_1;
+    new_loops[3].e = connecting_edge_1;
+  }
+}
+
+template<typename T>
+static VectorSet<int> vert_indices_from_edges(const Mesh &mesh, const Span<T> edge_indices)
+{
+  static_assert(is_same_any_v<T, int, int64_t>);
+
+  VectorSet<int> vert_indices;
+  vert_indices.reserve(edge_indices.size());
+  for (const T i_edge : edge_indices) {
+    const MEdge &edge = mesh.medge[i_edge];
+    vert_indices.add(edge.v1);
+    vert_indices.add(edge.v2);
+  }
+  return vert_indices;
+}
+
+static void extrude_mesh_edges(MeshComponent &component,
+                               const Field<bool> &selection_field,
+                               const Field<float3> &offset_field,
+                               const AttributeOutputs &attribute_outputs)
+{
+  Mesh &mesh = *component.get_for_write();
+  const int orig_vert_size = mesh.totvert;
+  Span<MEdge> orig_edges = mesh_edges(mesh);
+  Span<MPoly> orig_polys = mesh_polys(mesh);
+  const int orig_loop_size = mesh.totloop;
+
+  GeometryComponentFieldContext edge_context{component, ATTR_DOMAIN_EDGE};
+  FieldEvaluator edge_evaluator{edge_context, mesh.totedge};
+  edge_evaluator.set_selection(selection_field);
+  edge_evaluator.add(offset_field);
+  edge_evaluator.evaluate();
+  const IndexMask edge_selection = edge_evaluator.get_evaluated_selection_as_mask();
+  const VArray<float3> &edge_offsets = edge_evaluator.get_evaluated<float3>(0);
+  if (edge_selection.is_empty()) {
+    return;
+  }
+
+  const Array<Vector<int, 2>> edge_to_poly_map = mesh_calculate_polys_of_edge(mesh);
+
+  /* Find the offsets on the vertex domain for translation. This must be done before the mesh's
+   * custom data layers are reallocated, in case the virtual array references on of them. */
+  Array<float3> vert_offsets;
+  if (!edge_offsets.is_single()) {
+    vert_offsets.reinitialize(orig_vert_size);
+    attribute_math::DefaultPropatationMixer<float3> mixer(vert_offsets);
+    for (const int i_edge : edge_selection) {
+      const MEdge &edge = orig_edges[i_edge];
+      const float3 offset = edge_offsets[i_edge];
+      mixer.mix_in(edge.v1, offset);
+      mixer.mix_in(edge.v2, offset);
+    }
+    mixer.finalize();
+  }
+
+  const VectorSet<int> new_vert_indices = vert_indices_from_edges(mesh, edge_selection.indices());
+
+  const IndexRange new_vert_range{orig_vert_size, new_vert_indices.size()};
+  /* The extruded edges connect the original and duplicate edges. */
+  const IndexRange connect_edge_range{orig_edges.size(), new_vert_range.size()};
+  /* The duplicate edges are extruded copies of the selected edges. */
+  const IndexRange duplicate_edge_range = connect_edge_range.after(edge_selection.size());
+  /* There is a new polygon for every selected edge. */
+  const IndexRange new_poly_range{orig_polys.size(), edge_selection.size()};
+  /* Every new polygon is a quad with four corners. */
+  const IndexRange new_loop_range{orig_loop_size, new_poly_range.size() * 4};
+
+  expand_mesh(mesh,
+              new_vert_range.size(),
+              connect_edge_range.size() + duplicate_edge_range.size(),
+              new_poly_range.size(),
+              new_loop_range.size());
+
+  MutableSpan<MVert> new_verts = mesh_verts(mesh).slice(new_vert_range);
+  MutableSpan<MEdge> connect_edges = mesh_edges(mesh).slice(connect_edge_range);
+  MutableSpan<MEdge> duplicate_edges = mesh_edges(mesh).slice(duplicate_edge_range);
+  MutableSpan<MPoly> polys = mesh_polys(mesh);
+  MutableSpan<MPoly> new_polys = polys.slice(new_poly_range);
+  MutableSpan<MLoop> loops = mesh_loops(mesh);
+  MutableSpan<MLoop> new_loops = loops.slice(new_loop_range);
+
+  for (const int i : connect_edges.index_range()) {
+    connect_edges[i] = new_edge(new_vert_indices[i], new_vert_range[i]);
+  }
+
+  for (const int i : duplicate_edges.index_range()) {
+    const MEdge &orig_edge = mesh.medge[edge_selection[i]];
+    const int i_new_vert_1 = new_vert_indices.index_of(orig_edge.v1);
+    const int i_new_vert_2 = new_vert_indices.index_of(orig_edge.v2);
+    duplicate_edges[i] = new_edge(new_vert_range[i_new_vert_1], new_vert_range[i_new_vert_2]);
+  }
+
+  for (const int i : new_polys.index_range()) {
+    new_polys[i] = new_poly(new_loop_range[i * 4], 4);
+  }
+
+  for (const int i : edge_selection.index_range()) {
+    const int orig_edge_index = edge_selection[i];
+
+    const MEdge &duplicate_edge = duplicate_edges[i];
+    const int new_vert_1 = duplicate_edge.v1;
+    const int new_vert_2 = duplicate_edge.v2;
+    const int extrude_index_1 = new_vert_1 - orig_vert_size;
+    const int extrude_index_2 = new_vert_2 - orig_vert_size;
+
+    Span<int> connected_polys = edge_to_poly_map[orig_edge_index];
+
+    /* When there was a single polygon connected to the new polygon, we can use the old one to keep
+     * the face direction consistent. When there is more than one connected edge, the new face
+     * direction is totally arbitrary and the only goal for the behavior is to be deterministic. */
+    Span<MLoop> connected_poly_loops = {};
+    if (connected_polys.size() == 1) {
+      const MPoly &connected_poly = polys[connected_polys.first()];
+      connected_poly_loops = loops.slice(connected_poly.loopstart, connected_poly.totloop);
+    }
+    fill_quad_consistent_direction(connected_poly_loops,
+                                   new_loops.slice(4 * i, 4),
+                                   new_vert_indices[extrude_index_1],
+                                   new_vert_indices[extrude_index_2],
+                                   new_vert_1,
+                                   new_vert_2,
+                                   orig_edge_index,
+                                   connect_edge_range[extrude_index_1],
+                                   duplicate_edge_range[i],
+                                   connect_edge_range[extrude_index_2]);
+  }
+
+  /* Create a map of indices in the extruded vertices array to all of the indices of edges
+   * in the duplicate edges array that connect to that vertex. This can be used to simplify the
+   * mixing of attribute data for the connecting edges. */
+  const Array<Vector<int>> new_vert_to_duplicate_edge_map = create_vert_to_edge_map(
+      new_vert_range.size(), duplicate_edges, orig_vert_size);
+
+  component.attribute_foreach([&](const AttributeIDRef &id, const AttributeMetaData meta_data) {
+    OutputAttribute attribute = component.attribute_try_get_for_output(
+        id, meta_data.domain, meta_data.data_type);
+    if (!attribute) {
+      return true; /* Impossible to write the "normal" attribute. */
+    }
+
+    attribute_math::convert_to_static_type(meta_data.data_type, [&](auto dummy) {
+      using T = decltype(dummy);
+      MutableSpan<T> data = attribute.as_span().typed<T>();
+      switch (attribute.domain()) {
+        case ATTR_DOMAIN_POINT: {
+          /* New vertices copy the attribute values from their source vertex. */
+          copy_with_indices(data.slice(new_vert_range), data.as_span(), new_vert_indices);
+          break;
+        }
+        case ATTR_DOMAIN_EDGE: {
+          /* Edges parallel to original edges copy the edge attributes from the original edges. */
+          MutableSpan<T> duplicate_data = data.slice(duplicate_edge_range);
+          copy_with_mask(duplicate_data, data.as_span(), edge_selection);
+
+          /* Edges connected to original vertices mix values of selected connected edges. */
+          MutableSpan<T> connect_data = data.slice(connect_edge_range);
+          copy_with_mixing(connect_data, duplicate_data.as_span(), [&](const int i_new_vert) {
+            return new_vert_to_duplicate_edge_map[i_new_vert].as_span();
+          });
+          break;
+        }
+        case ATTR_DOMAIN_FACE: {
+          /* Attribute values for new faces are a mix of the values of faces connected to the its
+           * original edge.  */
+          copy_with_mixing(data.slice(new_poly_range), data.as_span(), [&](const int i) {
+            return edge_to_poly_map[edge_selection[i]].as_span();
+          });
+
+          break;
+        }
+        case ATTR_DOMAIN_CORNER: {
+          /* New corners get the average value of all adjacent corners on original faces connected
+           * to the original edge of their face. */
+          MutableSpan<T> new_data = data.slice(new_loop_range);
+          threading::parallel_for(edge_selection.index_range(), 256, [&](const IndexRange range) {
+            for (const int i_edge_selection : range) {
+              const int orig_edge_index = edge_selection[i_edge_selection];
+
+              Span<int> connected_polys = edge_to_poly_map[orig_edge_index];
+              if (connected_polys.is_empty()) {
+                /* If there are no connected polygons, there is no corner data to
+                 * interpolate. */
+                new_data.slice(4 * i_edge_selection, 4).fill(T());
+                continue;
+              }
+
+              /* Both corners on each vertical edge of the side polygon get the same value,
+               * so there are only two unique values to mix. */
+              Array<T> side_poly_corner_data(2);
+              attribute_math::DefaultPropatationMixer<T> mixer{side_poly_corner_data};
+
+              const MEdge &duplicate_edge = duplicate_edges[i_edge_selection];
+              const int new_vert_1 = duplicate_edge.v1;
+              const int new_vert_2 = duplicate_edge.v2;
+              const int orig_vert_1 = new_vert_indices[new_vert_1 - orig_vert_size];
+              const int orig_vert_2 = new_vert_indices[new_vert_2 - orig_vert_size];
+
+              /* Average the corner data from the corners that share a vertex from the
+               * polygons that share an edge with the extruded edge. */
+              for (const int i_connected_poly : connected_polys.index_range()) {
+                const MPoly &connected_poly = polys[connected_polys[i_connected_poly]];
+                for (const int i_loop :
+                     IndexRange(connected_poly.loopstart, connected_poly.totloop)) {
+                  const MLoop &loop = loops[i_loop];
+                  if (loop.v == orig_vert_1) {
+                    mixer.mix_in(0, data[i_loop]);
+                  }
+                  if (loop.v == orig_vert_2) {
+                    mixer.mix_in(1, data[i_loop]);
+                  }
+                }
+              }
+
+              mixer.finalize();
+
+              /* Instead of replicating the order in #fill_quad_consistent_direction here, it's
+               * simpler (though probably slower) to just match the corner data based on the vertex
+               * indices. */
+              for (const int i : IndexRange(4 * i_edge_selection, 4)) {
+                if (ELEM(new_loops[i].v, new_vert_1, orig_vert_1)) {
+                  new_data[i] = side_poly_corner_data.first();
+                }
+                else if (ELEM(new_loops[i].v, new_vert_2, orig_vert_2)) {
+                  new_data[i] = side_poly_corner_data.last();
+                }
+              }
+            }
+          });
+          break;
+        }
+        default:
+          BLI_assert_unreachable();
+      }
+    });
+
+    attribute.save();
+    return true;
+  });
+
+  if (edge_offsets.is_single()) {
+    const float3 offset = edge_offsets.get_internal_single();
+    threading::parallel_for(new_verts.index_range(), 1024, [&](const IndexRange range) {
+      for (const int i : range) {
+        add_v3_v3(new_verts[i].co, offset);
+      }
+    });
+  }
+  else {
+    threading::parallel_for(new_verts.index_range(), 1024, [&](const IndexRange range) {
+      for (const int i : range) {
+        add_v3_v3(new_verts[i].co, vert_offsets[new_vert_indices[i]]);
+      }
+    });
+  }
+
+  if (attribute_outputs.top_id) {
+    save_selection_as_attribute(
+        component, attribute_outputs.top_id.get(), ATTR_DOMAIN_EDGE, duplicate_edge_range);
+  }
+  if (attribute_outputs.side_id) {
+    save_selection_as_attribute(
+        component, attribute_outputs.side_id.get(), ATTR_DOMAIN_FACE, new_poly_range);
+  }
+
+  BKE_mesh_runtime_clear_cache(&mesh);
+  BKE_mesh_normals_tag_dirty(&mesh);
+}
+
+/**
+ * Edges connected to one selected face are on the boundary of a region and will be duplicated into
+ * a "side face". Edges inside a region will be duplicated to leave any original faces unchanged.
+ */
+static void extrude_mesh_face_regions(MeshComponent &component,
+                                      const Field<bool> &selection_field,
+                                      const Field<float3> &offset_field,
+                                      const AttributeOutputs &attribute_outputs)
+{
+  Mesh &mesh = *component.get_for_write();
+  const int orig_vert_size = mesh.totvert;
+  Span<MEdge> orig_edges = mesh_edges(mesh);
+  Span<MPoly> orig_polys = mesh_polys(mesh);
+  Span<MLoop> orig_loops = mesh_loops(mesh);
+
+  GeometryComponentFieldContext poly_context{component, ATTR_DOMAIN_FACE};
+  FieldEvaluator poly_evaluator{poly_context, mesh.totpoly};
+  poly_evaluator.set_selection(selection_field);
+  poly_evaluator.add(offset_field);
+  poly_evaluator.evaluate();
+  const IndexMask poly_selection = poly_evaluator.get_evaluated_selection_as_mask();
+  const VArray<float3> &poly_offsets = poly_evaluator.get_evaluated<float3>(0);
+  if (poly_selection.is_empty()) {
+    return;
+  }
+
+  Array<bool> poly_selection_array(orig_polys.size(), false);
+  for (const int i_poly : poly_selection) {
+    poly_selection_array[i_poly] = true;
+  }
+
+  /* Mix the offsets from the face domain to the vertex domain. Evaluate on the face domain above
+   * in order to be consistent with the selection, and to use the face normals rather than vertex
+   * normals as an offset, for example. */
+  Array<float3> vert_offsets;
+  if (!poly_offsets.is_single()) {
+    vert_offsets.reinitialize(orig_vert_size);
+    attribute_math::DefaultPropatationMixer<float3> mixer(vert_offsets);
+    for (const int i_poly : poly_selection) {
+      const MPoly &poly = orig_polys[i_poly];
+      const float3 offset = poly_offsets[i_poly];
+      for (const MLoop &loop : orig_loops.slice(poly.loopstart, poly.totloop)) {
+        mixer.mix_in(loop.v, offset);
+      }
+    }
+    mixer.finalize();
+  }
+
+  /* All of the faces (selected and deselected) connected to each edge. */
+  const Array<Vector<int, 2>> edge_to_poly_map = mesh_calculate_polys_of_edge(mesh);
+
+  /* All vertices that are connected to the selected polygons.
+   * Start the size at one vert per poly to reduce unnecessary reallocation. */
+  VectorSet<int> all_selected_verts;
+  all_selected_verts.reserve(orig_polys.size());
+  for (const int i_poly : poly_selection) {
+    const MPoly &poly = orig_polys[i_poly];
+    for (const MLoop &loop : orig_loops.slice(poly.loopstart, poly.totloop)) {
+      all_selected_verts.add(loop.v);
+    }
+  }
+
+  /* Edges inside of an extruded region that are also attached to deselected edges. They must be
+   * duplicated in order to leave the old edge attached to the unchanged deselected faces. */
+  VectorSet<int> new_inner_edge_indices;
+  /* Edges inside of an extruded region. Their vertices should be translated
+   * with the offset, but the edges themselves should not be duplicated. */
+  Vector<int> inner_edge_indices;
+  /* The extruded face corresponding to each boundary edge (and each boundary face). */
+  Vector<int> edge_extruded_face_indices;
+  /* Edges on the outside of selected regions, either because there are no
+   * other connected faces, or because all of the other faces aren't selected. */
+  VectorSet<int> boundary_edge_indices;
+  for (const int i_edge : orig_edges.index_range()) {
+    Span<int> polys = edge_to_poly_map[i_edge];
+
+    int i_selected_poly = -1;
+    int deselected_poly_count = 0;
+    int selected_poly_count = 0;
+    for (const int i_other_poly : polys) {
+      if (poly_selection_array[i_other_poly]) {
+        selected_poly_count++;
+        i_selected_poly = i_other_poly;
+      }
+      else {
+        deselected_poly_count++;
+      }
+    }
+
+    if (selected_poly_count == 1) {
+      /* If there is only one selected polygon connected to the edge,
+       * the edge should be extruded to form a "side face". */
+      boundary_edge_indices.add_new(i_edge);
+      edge_extruded_face_indices.append(i_selected_poly);
+    }
+    else if (selected_poly_count > 1) {
+      /* The edge is inside an extruded region of faces. */
+      if (deselected_poly_count > 0) {
+        /* Add edges that are also connected to deselected edges to a separate list. */
+        new_inner_edge_indices.add_new(i_edge);
+      }
+      else {
+        /* Otherwise, just keep track of edges inside the region so that
+         * we can reattach them to duplicated vertices if necessary. */
+        inner_edge_indices.append(i_edge);
+      }
+    }
+  }
+
+  VectorSet<int> new_vert_indices = vert_indices_from_edges(mesh, boundary_edge_indices.as_span());
+  /* Before adding the rest of the new vertices from the new inner edges, store the number
+   * of new vertices from the boundary edges, since this is the number of connecting edges. */
+  const int extruded_vert_size = new_vert_indices.size();
+
+  /* The vertices attached to duplicate inner edges also have to be duplicated. */
+  for (const int i_edge : new_inner_edge_indices) {
+    const MEdge &edge = mesh.medge[i_edge];
+    new_vert_indices.add(edge.v1);
+    new_vert_indices.add(edge.v2);
+  }
+
+  /* New vertices forming the duplicated boundary edges and the ends of the new inner edges. */
+  const IndexRange new_vert_range{orig_vert_size, new_vert_indices.size()};
+  /* One edge connects each selected vertex to a new vertex on the extruded polygons. */
+  const IndexRange connect_edge_range{orig_edges.size(), extruded_vert_size};
+  /* Each selected edge is duplicated to form a single edge on the extrusion. */
+  const IndexRange boundary_edge_range = connect_edge_range.after(boundary_edge_indices.size());
+  /* Duplicated edges inside regions that were connected to deselected faces. */
+  const IndexRange new_inner_edge_range = boundary_edge_range.after(new_inner_edge_indices.size());
+  /* Each edge selected for extrusion is extruded into a single face. */
+  const IndexRange side_poly_range{orig_polys.size(), boundary_edge_indices.size()};
+  /* The loops that form the new side faces. */
+  const IndexRange side_loop_range{orig_loops.size(), side_poly_range.size() * 4};
+
+  expand_mesh(mesh,
+              new_vert_range.size(),
+              connect_edge_range.size() + boundary_edge_range.size() + new_inner_edge_range.size(),
+              side_poly_range.size(),
+              side_loop_range.size());
+
+  MutableSpan<MEdge> edges = mesh_edges(mesh);
+  MutableSpan<MEdge> connect_edges = edges.slice(connect_edge_range);
+  MutableSpan<MEdge> boundary_edges = edges.slice(boundary_edge_range);
+  MutableSpan<MEdge> new_inner_edges = edges.slice(new_inner_edge_range);
+  MutableSpan<MPoly> polys = mesh_polys(mesh);
+  MutableSpan<MPoly> new_polys = polys.slice(side_poly_range);
+  MutableSpan<MLoop> loops = mesh_loops(mesh);
+  MutableSpan<MLoop> new_loops = loops.slice(side_loop_range);
+
+  /* Initialize the edges that form the sides of the extrusion. */
+  for (const int i : connect_edges.index_range()) {
+    connect_edges[i] = new_edge(new_vert_indices[i], new_vert_range[i]);
+  }
+
+  /* Initialize the edges that form the top of the extrusion. */
+  for (const int i : boundary_edges.index_range()) {
+    const MEdge &orig_edge = edges[boundary_edge_indices[i]];
+    const int i_new_vert_1 = new_vert_indices.index_of(orig_edge.v1);
+    const int i_new_vert_2 = new_vert_indices.index_of(orig_edge.v2);
+    boundary_edges[i] = new_edge(new_vert_range[i_new_vert_1], new_vert_range[i_new_vert_2]);
+  }
+
+  /* Initialize the new edges inside of extrude regions. */
+  for (const int i : new_inner_edge_indices.index_range()) {
+    const MEdge &orig_edge = edges[new_inner_edge_indices[i]];
+    const int i_new_vert_1 = new_vert_indices.index_of(orig_edge.v1);
+    const int i_new_vert_2 = new_vert_indices.index_of(orig_edge.v2);
+    new_inner_edges[i] = new_edge(new_vert_range[i_new_vert_1], new_vert_range[i_new_vert_2]);
+  }
+
+  /* Initialize the new side polygons. */
+  for (const int i : new_polys.index_range()) {
+    new_polys[i] = new_poly(side_loop_range[i * 4], 4);
+  }
+
+  /* Connect original edges inside face regions to any new vertices, if necessary. */
+  for (const int i : inner_edge_indices) {
+    MEdge &edge = edges[i];
+    const int i_new_vert_1 = new_vert_indices.index_of_try(edge.v1);
+    const int i_new_vert_2 = new_vert_indices.index_of_try(edge.v2);
+    if (i_new_vert_1 != -1) {
+      edge.v1 = new_vert_range[i_new_vert_1];
+    }
+    if (i_new_vert_2 != -1) {
+      edge.v2 = new_vert_range[i_new_vert_2];
+    }
+  }
+
+  /* Connect the selected faces to the extruded or duplicated edges and the new vertices. */
+  for (const int i_poly : poly_selection) {
+    const MPoly &poly = polys[i_poly];
+    for (MLoop &loop : loops.slice(poly.loopstart, poly.totloop)) {
+      const int i_new_vert = new_vert_indices.index_of_try(loop.v);
+      if (i_new_vert != -1) {
+        loop.v = new_vert_range[i_new_vert];
+      }
+      const int i_boundary_edge = boundary_edge_indices.index_of_try(loop.e);
+      if (i_boundary_edge != -1) {
+        loop.e = boundary_edge_range[i_boundary_edge];
+        /* Skip the next check, an edge cannot be both a boundary edge and an inner edge. */
+        continue;
+      }
+      const int i_new_inner_edge = new_inner_edge_indices.index_of_try(loop.e);
+      if (i_new_inner_edge != -1) {
+        loop.e = new_inner_edge_range[i_new_inner_edge];
+      }
+    }
+  }
+
+  /* Create the faces on the sides of extruded regions. */
+  for (const int i : boundary_edge_indices.index_range()) {
+    const MEdge &boundary_edge = boundary_edges[i];
+    const int new_vert_1 = boundary_edge.v1;
+    const int new_vert_2 = boundary_edge.v2;
+    const int extrude_index_1 = new_vert_1 - orig_vert_size;
+    const int extrude_index_2 = new_vert_2 - orig_vert_size;
+
+    const MPoly &extrude_poly = polys[edge_extruded_face_indices[i]];
+
+    fill_quad_consistent_direction(loops.slice(extrude_poly.loopstart, extrude_poly.totloop),
+                                   new_loops.slice(4 * i, 4),
+                                   new_vert_1,
+                                   new_vert_2,
+                                   new_vert_indices[extrude_index_1],
+                                   new_vert_indices[extrude_index_2],
+                                   boundary_edge_range[i],
+                                   connect_edge_range[extrude_index_1],
+                                   boundary_edge_indices[i],
+                                   connect_edge_range[extrude_index_2]);
+  }
+
+  /* Create a map of indices in the extruded vertices array to all of the indices of edges
+   * in the duplicate edges array that connect to that vertex. This can be used to simplify the
+   * mixing of attribute data for the connecting edges. */
+  const Array<Vector<int>> new_vert_to_duplicate_edge_map = create_vert_to_edge_map(
+      new_vert_range.size(), boundary_edges, orig_vert_size);
+
+  component.attribute_foreach([&](const AttributeIDRef &id, const AttributeMetaData meta_data) {
+    OutputAttribute attribute = component.attribute_try_get_for_output(
+        id, meta_data.domain, meta_data.data_type);
+    if (!attribute) {
+      return true; /* Impossible to write the "normal" attribute. */
+    }
+
+    attribute_math::convert_to_static_type(meta_data.data_type, [&](auto dummy) {
+      using T = decltype(dummy);
+      MutableSpan<T> data = attribute.as_span().typed<T>();
+      switch (attribute.domain()) {
+        case ATTR_DOMAIN_POINT: {
+          /* New vertices copy the attributes from their original vertices. */
+          copy_with_indices(data.slice(new_vert_range), data.as_span(), new_vert_indices);
+          break;
+        }
+        case ATTR_DOMAIN_EDGE: {
+          /* Edges parallel to original edges copy the edge attributes from the original edges. */
+          MutableSpan<T> boundary_data = data.slice(boundary_edge_range);
+          copy_with_indices(boundary_data, data.as_span(), boundary_edge_indices);
+
+          /* Edges inside of face regions also just duplicate their source data. */
+          MutableSpan<T> new_inner_data = data.slice(new_inner_edge_range);
+          copy_with_indices(new_inner_data, data.as_span(), new_inner_edge_indices);
+
+          /* Edges connected to original vertices mix values of selected connected edges. */
+          MutableSpan<T> connect_data = data.slice(connect_edge_range);
+          copy_with_mixing(connect_data, boundary_data.as_span(), [&](const int i) {
+            return new_vert_to_duplicate_edge_map[i].as_span();
+          });
+          break;
+        }
+        case ATTR_DOMAIN_FACE: {
+          /* New faces on the side of extrusions get the values from the corresponding selected
+           * face. */
+          copy_with_indices(
+              data.slice(side_poly_range), data.as_span(), edge_extruded_face_indices);
+          break;
+        }
+        case ATTR_DOMAIN_CORNER: {
+          /* New corners get the values from the corresponding corner on the extruded face. */
+          MutableSpan<T> new_data = data.slice(side_loop_range);
+          threading::parallel_for(
+              boundary_edge_indices.index_range(), 256, [&](const IndexRange range) {
+                for (const int i_boundary_edge : range) {
+                  const MPoly &poly = polys[edge_extruded_face_indices[i_boundary_edge]];
+
+                  const MEdge &boundary_edge = boundary_edges[i_boundary_edge];
+                  const int new_vert_1 = boundary_edge.v1;
+                  const int new_vert_2 = boundary_edge.v2;
+                  const int orig_vert_1 = new_vert_indices[new_vert_1 - orig_vert_size];
+                  const int orig_vert_2 = new_vert_indices[new_vert_2 - orig_vert_size];
+
+                  /* Retrieve the data for the first two sides of the quad from the extruded
+                   * polygon, which we generally expect to have just a small amount of sides. This
+                   * loop could be eliminated by adding a cache of connected loops (which would
+                   * also simplify some of the other code to find the correct loops on the extruded
+                   * face). */
+                  T data_1;
+                  T data_2;
+                  for (const int i_loop : IndexRange(poly.loopstart, poly.totloop)) {
+                    if (loops[i_loop].v == new_vert_1) {
+                      data_1 = data[i_loop];
+                    }
+                    if (loops[i_loop].v == new_vert_2) {
+                      data_2 = data[i_loop];
+                    }
+                  }
+
+                  /* Instead of replicating the order in #fill_quad_consistent_direction here, it's
+                   * simpler (though probably slower) to just match the corner data based on the
+                   * vertex indices. */
+                  for (const int i : IndexRange(4 * i_boundary_edge, 4)) {
+                    if (ELEM(new_loops[i].v, new_vert_1, orig_vert_1)) {
+                      new_data[i] = data_1;
+                    }
+                    else if (ELEM(new_loops[i].v, new_vert_2, orig_vert_2)) {
+                      new_data[i] = data_2;
+                    }
+                  }
+                }
+              });
+          break;
+        }
+        default:
+          BLI_assert_unreachable();
+      }
+    });
+
+    attribute.save();
+    return true;
+  });
+
+  /* Translate vertices based on the offset. If the vertex is used by a selected edge, it will
+   * have been duplicated and only the new vertex should use the offset. Otherwise the vertex might
+   * still need an offset, but it was reused on the inside of a region of extruded faces. */
+  if (poly_offsets.is_single()) {
+    const float3 offset = poly_offsets.get_internal_single();
+    threading::parallel_for(
+        IndexRange(all_selected_verts.size()), 1024, [&](const IndexRange range) {
+          for (const int i_orig : all_selected_verts.as_span().slice(range)) {
+            const int i_new = new_vert_indices.index_of_try(i_orig);
+            MVert &vert = mesh_verts(mesh)[(i_new == -1) ? i_orig : new_vert_range[i_new]];
+            add_v3_v3(vert.co, offset);
+          }
+        });
+  }
+  else {
+    threading::parallel_for(
+        IndexRange(all_selected_verts.size()), 1024, [&](const IndexRange range) {
+          for (const int i_orig : all_selected_verts.as_span().slice(range)) {
+            const int i_new = new_vert_indices.index_of_try(i_orig);
+            const float3 offset = vert_offsets[i_orig];
+            MVert &vert = mesh_verts(mesh)[(i_new == -1) ? i_orig : new_vert_range[i_new]];
+            add_v3_v3(vert.co, offset);
+          }
+        });
+  }
+
+  if (attribute_outputs.top_id) {
+    save_selection_as_attribute(
+        component, attribute_outputs.top_id.get(), ATTR_DOMAIN_FACE, poly_selection);
+  }
+  if (attribute_outputs.side_id) {
+    save_selection_as_attribute(
+        component, attribute_outputs.side_id.get(), ATTR_DOMAIN_FACE, side_poly_range);
+  }
+
+  BKE_mesh_runtime_clear_cache(&mesh);
+  BKE_mesh_normals_tag_dirty(&mesh);
+}
+
+/* Get the range into an array of extruded corners, edges, or vertices for a particular polygon. */
+static IndexRange selected_corner_range(Span<int> offsets, const int index)
+{
+  const int offset = offsets[index];
+  const int next_offset = offsets[index + 1];
+  return IndexRange(offset, next_offset - offset);
+}
+
+static void extrude_individual_mesh_faces(MeshComponent &component,
+                                          const Field<bool> &selection_field,
+                                          const Field<float3> &offset_field,
+                                          const AttributeOutputs &attribute_outputs)
+{
+  Mesh &mesh = *component.get_for_write();
+  const int orig_vert_size = mesh.totvert;
+  const int orig_edge_size = mesh.totedge;
+  Span<MPoly> orig_polys = mesh_polys(mesh);
+  Span<MLoop> orig_loops = mesh_loops(mesh);
+
+  /* Use a mesh for the result of the evaluation because the mesh is reallocated before
+   * the vertices are moved, and the evaluated result might reference an attribute. */
+  Array<float3> poly_offset(orig_polys.size());
+  GeometryComponentFieldContext poly_context{component, ATTR_DOMAIN_FACE};
+  FieldEvaluator poly_evaluator{poly_context, mesh.totpoly};
+  poly_evaluator.set_selection(selection_field);
+  poly_evaluator.add_with_destination(offset_field, poly_offset.as_mutable_span());
+  poly_evaluator.evaluate();
+  const IndexMask poly_selection = poly_evaluator.get_evaluated_selection_as_mask();
+
+  /* Build an array of offsets into the new data for each polygon. This is used to facilitate
+   * parallelism later on by avoiding the need to keep track of an offset when iterating through
+   * all polygons. */
+  int extrude_corner_size = 0;
+  Array<int> index_offsets(poly_selection.size() + 1);
+  for (const int i_selection : poly_selection.index_range()) {
+    const MPoly &poly = orig_polys[poly_selection[i_selection]];
+    index_offsets[i_selection] = extrude_corner_size;
+    extrude_corner_size += poly.totloop;
+  }
+  index_offsets.last() = extrude_corner_size;
+
+  const IndexRange new_vert_range{orig_vert_size, extrude_corner_size};
+  /* One edge connects each selected vertex to a new vertex on the extruded polygons. */
+  const IndexRange connect_edge_range{orig_edge_size, extrude_corner_size};
+  /* Each selected edge is duplicated to form a single edge on the extrusion. */
+  const IndexRange duplicate_edge_range = connect_edge_range.after(extrude_corner_size);
+  /* Each edge selected for extrusion is extruded into a single face. */
+  const IndexRange side_poly_range{orig_polys.size(), duplicate_edge_range.size()};
+  const IndexRange side_loop_range{orig_loops.size(), side_poly_range.size() * 4};
+
+  expand_mesh(mesh,
+              new_vert_range.size(),
+              connect_edge_range.size() + duplicate_edge_range.size(),
+              side_poly_range.size(),
+              side_loop_range.size());
+
+  MutableSpan<MVert> new_verts = mesh_verts(mesh).slice(new_vert_range);
+  MutableSpan<MEdge> edges{mesh.medge, mesh.totedge};
+  MutableSpan<MEdge> connect_edges = edges.slice(connect_edge_range);
+  MutableSpan<MEdge> duplicate_edges = edges.slice(duplicate_edge_range);
+  MutableSpan<MPoly> polys{mesh.mpoly, mesh.totpoly};
+  MutableSpan<MPoly> new_polys = polys.slice(side_poly_range);
+  MutableSpan<MLoop> loops{mesh.mloop, mesh.totloop};
+
+  /* For every selected polygon, build the faces that form the sides of the extrusion. Filling some
+   * of this data like the new edges or polygons could be easily split into separate loops, which
+   * may or may not be faster, and would involve more duplication. */
+  threading::parallel_for(poly_selection.index_range(), 256, [&](const IndexRange range) {
+    for (const int i_selection : range) {
+      const IndexRange poly_corner_range = selected_corner_range(index_offsets, i_selection);
+
+      const MPoly &poly = polys[poly_selection[i_selection]];
+      Span<MLoop> poly_loops = loops.slice(poly.loopstart, poly.totloop);
+
+      for (const int i : IndexRange(poly.totloop)) {
+        const int i_next = (i == poly.totloop - 1) ? 0 : i + 1;
+        const MLoop &orig_loop = poly_loops[i];
+        const MLoop &orig_loop_next = poly_loops[i_next];
+
+        const int i_extrude = poly_corner_range[i];
+        const int i_extrude_next = poly_corner_range[i_next];
+
+        const int i_duplicate_edge = duplicate_edge_range[i_extrude];
+        const int new_vert = new_vert_range[i_extrude];
+        const int new_vert_next = new_vert_range[i_extrude_next];
+
+        const int orig_edge = orig_loop.e;
+
+        const int orig_vert = orig_loop.v;
+        const int orig_vert_next = orig_loop_next.v;
+
+        duplicate_edges[i_extrude] = new_edge(new_vert, new_vert_next);
+
+        new_polys[i_extrude] = new_poly(side_loop_range[i_extrude * 4], 4);
+
+        MutableSpan<MLoop> side_loops = loops.slice(side_loop_range[i_extrude * 4], 4);
+        side_loops[0].v = new_vert_next;
+        side_loops[0].e = i_duplicate_edge;
+        side_loops[1].v = new_vert;
+        side_loops[1].e = connect_edge_range[i_extrude];
+        side_loops[2].v = orig_vert;
+        side_loops[2].e = orig_edge;
+        side_loops[3].v = orig_vert_next;
+        side_loops[3].e = connect_edge_range[i_extrude_next];
+
+        connect_edges[i_extrude] = new_edge(orig_vert, new_vert);
+      }
+    }
+  });
+
+  component.attribute_foreach([&](const AttributeIDRef &id, const AttributeMetaData meta_data) {
+    OutputAttribute attribute = component.attribute_try_get_for_output(
+        id, meta_data.domain, meta_data.data_type);
+    if (!attribute) {
+      return true; /* Impossible to write the "normal" attribute. */
+    }
+
+    attribute_math::convert_to_static_type(meta_data.data_type, [&](auto dummy) {
+      using T = decltype(dummy);
+      MutableSpan<T> data = attribute.as_span().typed<T>();
+      switch (attribute.domain()) {
+        case ATTR_DOMAIN_POINT: {
+          /* New vertices copy the attributes from their original vertices. */
+          MutableSpan<T> new_data = data.slice(new_vert_range);
+
+          threading::parallel_for(poly_selection.index_range(), 1024, [&](const IndexRange range) {
+            for (const int i_selection : range) {
+              const MPoly &poly = polys[poly_selection[i_selection]];
+              Span<MLoop> poly_loops = loops.slice(poly.loopstart, poly.totloop);
+
+              const int corner_offset = index_offsets[i_selection];
+              for (const int i : poly_loops.index_range()) {
+                const int orig_index = poly_loops[i].v;
+                new_data[corner_offset + i] = data[orig_index];
+              }
+            }
+          });
+          break;
+        }
+        case ATTR_DOMAIN_EDGE: {
+          MutableSpan<T> duplicate_data = data.slice(duplicate_edge_range);
+          MutableSpan<T> connect_data = data.slice(connect_edge_range);
+
+          threading::parallel_for(poly_selection.index_range(), 512, [&](const IndexRange range) {
+            for (const int i_selection : range) {
+              const MPoly &poly = polys[poly_selection[i_selection]];
+              Span<MLoop> poly_loops = loops.slice(poly.loopstart, poly.totloop);
+
+              const IndexRange poly_corner_range = selected_corner_range(index_offsets,
+                                                                         i_selection);
+
+              /* The data for the duplicate edge is simply a copy of the original edge's data. */
+              for (const int i : poly_loops.index_range()) {
+                const int orig_index = poly_loops[i].e;
+                duplicate_data[poly_corner_range[i]] = data[orig_index];
+              }
+
+              /* For the extruded edges, mix the data from the two neighboring original edges of
+               * the extruded polygon. */
+              for (const int i : poly_loops.index_range()) {
+                const int i_loop_prev = (i == 0) ? poly.totloop - 1 : i - 1;
+                const int orig_index = poly_loops[i].e;
+                const int orig_index_prev = poly_loops[i_loop_prev].e;
+                if constexpr (std::is_same_v<T, bool>) {
+                  /* Propagate selections with "or" instead of "at least half". */
+                  connect_data[poly_corner_range[i]] = data[orig_index] || data[orig_index_prev];
+                }
+                else {
+                  connect_data[poly_corner_range[i]] = attribute_math::mix2(
+                      0.5f, data[orig_index], data[orig_index_prev]);
+                }
+              }
+            }
+          });
+          break;
+        }
+        case ATTR_DOMAIN_FACE: {
+          /* Each side face gets the values from the corresponding new face. */
+          MutableSpan<T> new_data = data.slice(side_poly_range);
+          threading::parallel_for(poly_selection.index_range(), 1024, [&](const IndexRange range) {
+            for (const int i_selection : range) {
+              const int poly_index = poly_selection[i_selection];
+              const IndexRange poly_corner_range = selected_corner_range(index_offsets,
+                                                                         i_selection);
+              new_data.slice(poly_corner_range).fill(data[poly_index]);
+            }
+          });
+          break;
+        }
+        case ATTR_DOMAIN_CORNER: {
+          /* Each corner on a side face gets its value from the matching corner on an extruded
+           * face. */
+          MutableSpan<T> new_data = data.slice(side_loop_range);
+          threading::parallel_for(poly_selection.index_range(), 256, [&](const IndexRange range) {
+            for (const int i_selection : range) {
+              const MPoly &poly = polys[poly_selection[i_selection]];
+              Span<T> poly_loop_data = data.slice(poly.loopstart, poly.totloop);
+              const IndexRange poly_corner_range = selected_corner_range(index_offsets,
+                                                                         i_selection);
+
+              for (const int i : IndexRange(poly.totloop)) {
+                const int i_next = (i == poly.totloop - 1) ? 0 : i + 1;
+                const int i_extrude = poly_corner_range[i];
+
+                MutableSpan<T> side_loop_data = new_data.slice(i_extrude * 4, 4);
+
+                /* The two corners on each side of the side polygon get the data from the matching
+                 * corners of the extruded polygon. This order depends on the loop filling the loop
+                 * indices. */
+                side_loop_data[0] = poly_loop_data[i_next];
+                side_loop_data[1] = poly_loop_data[i];
+                side_loop_data[2] = poly_loop_data[i];
+                side_loop_data[3] = poly_loop_data[i_next];
+              }
+            }
+          });
+          break;
+        }
+        default:
+          BLI_assert_unreachable();
+      }
+    });
+
+    attribute.save();
+    return true;
+  });
+
+  /* Offset the new vertices. */
+  threading::parallel_for(poly_selection.index_range(), 1024, [&](const IndexRange range) {
+    for (const int i_selection : range) {
+      const IndexRange poly_corner_range = selected_corner_range(index_offsets, i_selection);
+      for (MVert &vert : new_verts.slice(poly_corner_range)) {
+        add_v3_v3(vert.co, poly_offset[poly_selection[i_selection]]);
+      }
+    }
+  });
+
+  /* Finally update each extruded polygon's loops to point to the new edges and vertices.
+   * This must be done last, because they were used to find original indices for attribute
+   * interpolation before. Alternatively an original index array could be built for each domain. */
+  threading::parallel_for(poly_selection.index_range(), 256, [&](const IndexRange range) {
+    for (const int i_selection : range) {
+      const IndexRange poly_corner_range = selected_corner_range(index_offsets, i_selection);
+
+      const MPoly &poly = polys[poly_selection[i_selection]];
+      MutableSpan<MLoop> poly_loops = loops.slice(poly.loopstart, poly.totloop);
+
+      for (const int i : IndexRange(poly.totloop)) {
+        MLoop &loop = poly_loops[i];
+        loop.v = new_vert_range[poly_corner_range[i]];
+        loop.e = duplicate_edge_range[poly_corner_range[i]];
+      }
+    }
+  });
+
+  if (attribute_outputs.top_id) {
+    save_selection_as_attribute(
+        component, attribute_outputs.top_id.get(), ATTR_DOMAIN_FACE, poly_selection);
+  }
+  if (attribute_outputs.side_id) {
+    save_selection_as_attribute(
+        component, attribute_outputs.side_id.get(), ATTR_DOMAIN_FACE, side_poly_range);
+  }
+
+  BKE_mesh_runtime_clear_cache(&mesh);
+  BKE_mesh_normals_tag_dirty(&mesh);
+}
+
+static void node_geo_exec(GeoNodeExecParams params)
+{
+  GeometrySet geometry_set = params.extract_input<GeometrySet>("Mesh");
+  Field<bool> selection = params.extract_input<Field<bool>>("Selection");
+  Field<float3> offset_field = params.extract_input<Field<float3>>("Offset");
+  Field<float> scale_field = params.extract_input<Field<float>>("Offset Scale");
+  const NodeGeometryExtrudeMesh &storage = node_storage(params.node());
+  GeometryNodeExtrudeMeshMode mode = static_cast<GeometryNodeExtrudeMeshMode>(storage.mode);
+
+  /* Create a combined field from the offset and the scale so the field evaluator
+   * can take care of the multiplication and to simplify each extrude function. */
+  static fn::CustomMF_SI_SI_SO<float3, float, float3> multiply_fn{
+      "Scale", [](const float3 &offset, const float scale) { return offset * scale; }};
+  std::shared_ptr<FieldOperation> multiply_op = std::make_shared<FieldOperation>(
+      FieldOperation(multiply_fn, {std::move(offset_field), std::move(scale_field)}));
+  const Field<float3> final_offset{std::move(multiply_op)};
+
+  AttributeOutputs attribute_outputs;
+  if (params.output_is_required("Top")) {
+    attribute_outputs.top_id = StrongAnonymousAttributeID("Top");
+  }
+  if (params.output_is_required("Side")) {
+    attribute_outputs.side_id = StrongAnonymousAttributeID("Side");
+  }
+
+  const bool extrude_individual = mode == GEO_NODE_EXTRUDE_MESH_FACES &&
+                                  params.extract_input<bool>("Individual");
+
+  geometry_set.modify_geometry_sets([&](GeometrySet &geometry_set) {
+    if (geometry_set.has_mesh()) {
+      MeshComponent &component = geometry_set.get_component_for_write<MeshComponent>();
+      switch (mode) {
+        case GEO_NODE_EXTRUDE_MESH_VERTICES:
+          extrude_mesh_vertices(component, selection, final_offset, attribute_outputs);
+          break;
+        case GEO_NODE_EXTRUDE_MESH_EDGES:
+          extrude_mesh_edges(component, selection, final_offset, attribute_outputs);
+          break;
+        case GEO_NODE_EXTRUDE_MESH_FACES: {
+          if (extrude_individual) {
+            extrude_individual_mesh_faces(component, selection, final_offset, attribute_outputs);
+          }
+          else {
+            extrude_mesh_face_regions(component, selection, final_offset, attribute_outputs);
+          }
+          break;
+        }
+      }
+
+      BLI_assert(BKE_mesh_is_valid(component.get_for_write()));
+    }
+  });
+
+  params.set_output("Mesh", std::move(geometry_set));
+  if (attribute_outputs.top_id) {
+    params.set_output("Top",
+                      AnonymousAttributeFieldInput::Create<bool>(
+                          std::move(attribute_outputs.top_id), params.attribute_producer_name()));
+  }
+  if (attribute_outputs.side_id) {
+    params.set_output("Side",
+                      AnonymousAttributeFieldInput::Create<bool>(
+                          std::move(attribute_outputs.side_id), params.attribute_producer_name()));
+  }
+}
+
+}  // namespace blender::nodes::node_geo_extrude_mesh_cc
+
+void register_node_type_geo_extrude_mesh()
+{
+  namespace file_ns = blender::nodes::node_geo_extrude_mesh_cc;
+
+  static bNodeType ntype;
+  geo_node_type_base(&ntype, GEO_NODE_EXTRUDE_MESH, "Extrude Mesh", NODE_CLASS_GEOMETRY);
+  ntype.declare = file_ns::node_declare;
+  node_type_init(&ntype, file_ns::node_init);
+  node_type_update(&ntype, file_ns::node_update);
+  ntype.geometry_node_execute = file_ns::node_geo_exec;
+  node_type_storage(
+      &ntype, "NodeGeometryExtrudeMesh", node_free_standard_storage, node_copy_standard_storage);
+  ntype.draw_buttons = file_ns::node_layout;
+  nodeRegisterType(&ntype);
+}