Transfer Data: add main core code and operators.

This add code needed to map a CD data layout from source mesh towards destination one,
and code needed to actually transfer data, using BKE's mesh remap generated data.

This allows to transfer most CD layers (vgroups, vcols, uvs...) as well as fake, boolean ones
(like smooth/sharp edges/faces, etc.). Some types are not yet transferable, mainly
shape keys, this is known TODO.

Data transfer can also use some advanced mixing in some cases (mostly, vgroups and vcols).

Notes:
* New transfer operators transfer data from active object towards selected ones.
* Modifier will be committed separately.
* Old weight transfer code (for vgroups) is kept for now, mostly because it is the only
  usable one in weightpaint mode (it transfers from selected object to active one,
  this is not sensible in Object mode, but needed in WeightPaint one). This will be addressed soon.

Again, heavily reviewed and enhanced by Campbell, thanks!

4 files changed, 632 insertions, 0 deletions

diff --git a/source/blender/editors/object/CMakeLists.txt b/source/blender/editors/object/CMakeLists.txt
index 9b380ff8d48..79437bb05b9 100644
--- a/source/blender/editors/object/CMakeLists.txt
+++ b/source/blender/editors/object/CMakeLists.txt
@@ -56,6 +56,7 @@ set(SRC
 	object_relations.c
 	object_select.c
 	object_shapekey.c
+	object_data_transfer.c
 	object_transform.c
 	object_warp.c
 	object_vgroup.c
diff --git a/source/blender/editors/object/object_data_transfer.c b/source/blender/editors/object/object_data_transfer.c
new file mode 100644
index 00000000000..1d994746ba6
--- /dev/null
+++ b/source/blender/editors/object/object_data_transfer.c
@@ -0,0 +1,620 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * 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.
+ *
+ * The Original Code is Copyright (C) 2014 by Blender Foundation.
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): Bastien Montagne.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/editors/object/object_transfer_data.c
+ *  \ingroup edobj
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_modifier_types.h"
+#include "DNA_object_types.h"
+#include "DNA_scene_types.h"
+
+#include "BLI_math.h"
+#include "BLI_blenlib.h"
+#include "BLI_utildefines.h"
+
+#include "BKE_context.h"
+#include "BKE_object_data_transfer.h"
+#include "BKE_DerivedMesh.h"
+#include "BKE_mesh_mapping.h"
+#include "BKE_mesh_remap.h"
+#include "BKE_object.h"
+#include "BKE_report.h"
+
+#include "RNA_access.h"
+#include "RNA_define.h"
+#include "RNA_enum_types.h"
+
+#include "WM_api.h"
+#include "WM_types.h"
+
+#include "ED_object.h"
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "object_intern.h"
+
+/* All possible data to transfer.
+ * Note some are 'fake' ones, i.e. they are not hold by real CDLayers. */
+/* Not shared with modifier, since we use a usual enum here, not a multi-choice one. */
+static EnumPropertyItem DT_layer_items[] = {
+	{0, "", 0, "Vertex Data", ""},
+	{DT_TYPE_MDEFORMVERT, "VGROUP_WEIGHTS", 0, "Vertex Group(s)", "Transfer active or all vertex groups"},
+#if 0  /* XXX For now, would like to finish/merge work from 2014 gsoc first. */
+	{DT_TYPE_SHAPEKEY, "SHAPEKEYS", 0, "Shapekey(s)", "Transfer active or all shape keys"},
+#endif
+#if 0  /* XXX When SkinModifier is enabled, it seems to erase its own CD_MVERT_SKIN layer from final DM :( */
+	{DT_TYPE_SKIN, "SKIN", 0, "Skin Weight", "Transfer skin weights"},
+#endif
+	{DT_TYPE_BWEIGHT_VERT, "BEVEL_WEIGHT_VERT", 0, "Bevel Weight", "Transfer bevel weights"},
+	{0, "", 0, "Edge Data", ""},
+	{DT_TYPE_SHARP_EDGE, "SHARP_EDGE", 0, "Sharp", "Transfer sharp mark"},
+	{DT_TYPE_SEAM, "SEAM", 0, "UV Seam", "Transfer UV seam mark"},
+	{DT_TYPE_CREASE, "CREASE", 0, "Subsurf Crease", "Transfer crease values"},
+	{DT_TYPE_BWEIGHT_EDGE, "BEVEL_WEIGHT_EDGE", 0, "Bevel Weight", "Transfer bevel weights"},
+	{DT_TYPE_FREESTYLE_EDGE, "FREESTYLE_EDGE", 0, "Freestyle Mark", "Transfer Freestyle edge mark"},
+	{0, "", 0, "Face Corner Data", ""},
+	{DT_TYPE_VCOL, "VCOL", 0, "VCol", "Vertex (face corners) colors"},
+	{DT_TYPE_UV, "UV", 0, "UVs", "Transfer UV layers"},
+	{0, "", 0, "Face Data", ""},
+	{DT_TYPE_SHARP_FACE, "SMOOTH", 0, "Smooth", "Transfer flat/smooth mark"},
+	{DT_TYPE_FREESTYLE_FACE, "FREESTYLE_FACE", 0, "Freestyle Mark", "Transfer Freestyle face mark"},
+	{0, NULL, 0, NULL, NULL}
+};
+
+/* Note: DT_layers_select_src_items enum is from rna_modifier.c */
+static EnumPropertyItem *dt_layers_select_src_itemf(
+        bContext *C, PointerRNA *ptr, PropertyRNA *UNUSED(prop), bool *r_free)
+{
+	EnumPropertyItem *item = NULL, tmp_item = {0};
+	int totitem = 0;
+
+	const int data_type = RNA_enum_get(ptr, "data_type");
+
+	if (!C) {  /* needed for docs and i18n tools */
+		return DT_layers_select_src_items;
+	}
+
+	RNA_enum_items_add_value(&item, &totitem, DT_layers_select_src_items, DT_LAYERS_ACTIVE_SRC);
+	RNA_enum_items_add_value(&item, &totitem, DT_layers_select_src_items, DT_LAYERS_ALL_SRC);
+
+	if (data_type == DT_TYPE_MDEFORMVERT) {
+		Object *ob_src = CTX_data_active_object(C);
+
+		if (BKE_object_pose_armature_get(ob_src)) {
+			RNA_enum_items_add_value(&item, &totitem, DT_layers_select_src_items, DT_LAYERS_VGROUP_SRC_BONE_SELECT);
+			RNA_enum_items_add_value(&item, &totitem, DT_layers_select_src_items, DT_LAYERS_VGROUP_SRC_BONE_DEFORM);
+		}
+
+		if (ob_src) {
+			bDeformGroup *dg;
+			int i;
+
+			RNA_enum_item_add_separator(&item, &totitem);
+
+			for (i = 0, dg = ob_src->defbase.first; dg; i++, dg = dg->next) {
+				tmp_item.value = i;
+				tmp_item.identifier = tmp_item.name = dg->name;
+				RNA_enum_item_add(&item, &totitem, &tmp_item);
+			}
+		}
+	}
+	else if (data_type == DT_TYPE_SHAPEKEY) {
+		/* TODO */
+	}
+	else if (data_type == DT_TYPE_UV) {
+		Object *ob_src = CTX_data_active_object(C);
+		Scene *scene = CTX_data_scene(C);
+
+		if (ob_src) {
+			DerivedMesh *dm_src;
+			CustomData *pdata;
+			int num_data, i;
+
+			/* XXX Is this OK? */
+			dm_src = mesh_get_derived_final(scene, ob_src, CD_MASK_BAREMESH | CD_MTEXPOLY);
+			pdata = dm_src->getPolyDataLayout(dm_src);
+			num_data = CustomData_number_of_layers(pdata, CD_MTEXPOLY);
+
+			RNA_enum_item_add_separator(&item, &totitem);
+
+			for (i = 0; i < num_data; i++) {
+				tmp_item.value = i;
+				tmp_item.identifier = tmp_item.name = CustomData_get_layer_name(pdata, CD_MTEXPOLY, i);
+				RNA_enum_item_add(&item, &totitem, &tmp_item);
+			}
+		}
+	}
+	else if (data_type == DT_TYPE_VCOL) {
+		Object *ob_src = CTX_data_active_object(C);
+		Scene *scene = CTX_data_scene(C);
+
+		if (ob_src) {
+			DerivedMesh *dm_src;
+			CustomData *ldata;
+			int num_data, i;
+
+			/* XXX Is this OK? */
+			dm_src = mesh_get_derived_final(scene, ob_src, CD_MASK_BAREMESH | CD_MLOOPCOL);
+			ldata = dm_src->getLoopDataLayout(dm_src);
+			num_data = CustomData_number_of_layers(ldata, CD_MLOOPCOL);
+
+			RNA_enum_item_add_separator(&item, &totitem);
+
+			for (i = 0; i < num_data; i++) {
+				tmp_item.value = i;
+				tmp_item.identifier = tmp_item.name = CustomData_get_layer_name(ldata, CD_MLOOPCOL, i);
+				RNA_enum_item_add(&item, &totitem, &tmp_item);
+			}
+		}
+	}
+
+	RNA_enum_item_end(&item, &totitem);
+	*r_free = true;
+
+	return item;
+}
+
+/* Note: DT_layers_select_dst_items enum is from rna_modifier.c */
+static EnumPropertyItem *dt_layers_select_dst_itemf(bContext *C, PointerRNA *ptr, PropertyRNA *UNUSED(prop), bool *r_free)
+{
+	EnumPropertyItem *item = NULL;
+	int totitem = 0;
+
+	const int layers_select_src = RNA_enum_get(ptr, "layers_select_src");
+
+	if (!C) {  /* needed for docs and i18n tools */
+		return DT_layers_select_dst_items;
+	}
+
+	if (layers_select_src == DT_LAYERS_ACTIVE_SRC || layers_select_src >= 0) {
+		RNA_enum_items_add_value(&item, &totitem, DT_layers_select_dst_items, DT_LAYERS_ACTIVE_DST);
+	}
+	RNA_enum_items_add_value(&item, &totitem, DT_layers_select_dst_items, DT_LAYERS_NAME_DST);
+	RNA_enum_items_add_value(&item, &totitem, DT_layers_select_dst_items, DT_LAYERS_INDEX_DST);
+
+	/* No 'specific' to-layers here, since we may transfer to several objects at once! */
+
+	RNA_enum_item_end(&item, &totitem);
+	*r_free = true;
+
+	return item;
+}
+
+/* Note: DT_mix_mode_items enum is from rna_modifier.c */
+static EnumPropertyItem *dt_mix_mode_itemf(bContext *C, PointerRNA *ptr, PropertyRNA *UNUSED(prop), bool *r_free)
+{
+	EnumPropertyItem *item = NULL;
+	int totitem = 0;
+
+	const int dtdata_type = RNA_enum_get(ptr, "data_type");
+	bool support_advanced_mixing, support_threshold;
+
+	if (!C) {  /* needed for docs and i18n tools */
+		return DT_mix_mode_items;
+	}
+
+	RNA_enum_items_add_value(&item, &totitem, DT_mix_mode_items, CDT_MIX_TRANSFER);
+
+	BKE_object_data_transfer_get_dttypes_capacity(dtdata_type, &support_advanced_mixing, &support_threshold);
+
+	if (support_advanced_mixing) {
+		RNA_enum_items_add_value(&item, &totitem, DT_mix_mode_items, CDT_MIX_REPLACE_ABOVE_THRESHOLD);
+		RNA_enum_items_add_value(&item, &totitem, DT_mix_mode_items, CDT_MIX_REPLACE_BELOW_THRESHOLD);
+	}
+
+	if (support_advanced_mixing) {
+		RNA_enum_item_add_separator(&item, &totitem);
+		RNA_enum_items_add_value(&item, &totitem, DT_mix_mode_items, CDT_MIX_MIX);
+		RNA_enum_items_add_value(&item, &totitem, DT_mix_mode_items, CDT_MIX_ADD);
+		RNA_enum_items_add_value(&item, &totitem, DT_mix_mode_items, CDT_MIX_SUB);
+		RNA_enum_items_add_value(&item, &totitem, DT_mix_mode_items, CDT_MIX_MUL);
+	}
+
+	RNA_enum_item_end(&item, &totitem);
+	*r_free = true;
+
+	return item;
+}
+
+static bool data_transfer_check(bContext *UNUSED(C), wmOperator *op)
+{
+	const int layers_select_src = RNA_enum_get(op->ptr, "layers_select_src");
+	PropertyRNA *prop = RNA_struct_find_property(op->ptr, "layers_select_dst");
+	const int layers_select_dst = RNA_property_enum_get(op->ptr, prop);
+
+	/* TODO: check for invalid layers_src select modes too! */
+
+	if ((layers_select_src != DT_LAYERS_ACTIVE_SRC) && (layers_select_dst == DT_LAYERS_ACTIVE_DST)) {
+		RNA_property_enum_set(op->ptr, prop, DT_LAYERS_NAME_DST);
+		return true;
+	}
+
+	return false;
+}
+
+/* Helper, used by both data_transfer_exec and datalayout_transfer_exec. */
+static void data_transfer_exec_preprocess_objects(bContext *C, wmOperator *op, Object *ob_src, ListBase *ctx_objects)
+{
+	CollectionPointerLink *ctx_ob;
+	CTX_data_selected_editable_objects(C, ctx_objects);
+
+	for (ctx_ob = ctx_objects->first; ctx_ob; ctx_ob = ctx_ob->next) {
+		Object *ob = ctx_ob->ptr.data;
+		Mesh *me;
+		if ((ob == ob_src) || (ob->type != OB_MESH)) {
+			continue;
+		}
+
+		me = ob->data;
+		if (me->id.lib) {
+			/* Do not transfer to linked data, not supported. */
+			BKE_reportf(op->reports, RPT_WARNING, "Skipping object '%s', linked data '%s' cannot be modified",
+			            ob->id.name + 2, me->id.name + 2);
+			me->id.flag &= ~LIB_DOIT;
+			continue;
+		}
+
+		me->id.flag |= LIB_DOIT;
+	}
+}
+
+/* Helper, used by both data_transfer_exec and datalayout_transfer_exec. */
+static bool data_transfer_exec_is_object_valid(wmOperator *op, Object *ob_src, Object *ob_dst)
+{
+	Mesh *me;
+	if ((ob_dst == ob_src) || (ob_dst->type != OB_MESH)) {
+		return false;
+	}
+
+	me = ob_dst->data;
+	if (me->id.flag & LIB_DOIT) {
+		me->id.flag &= ~LIB_DOIT;
+		return true;
+	}
+	else if (me->id.lib == NULL) {
+		/* Do not transfer apply operation more than once. */
+		/* XXX This is not nice regarding vgroups, which are half-Object data... :/ */
+		BKE_reportf(op->reports, RPT_WARNING,
+		            "Skipping object '%s', data '%s' has already been processed with a previous object",
+		            ob_dst->id.name + 2, me->id.name + 2);
+	}
+	return false;
+}
+
+static int data_transfer_exec(bContext *C, wmOperator *op)
+{
+	Scene *scene = CTX_data_scene(C);
+	Object *ob_src = CTX_data_active_object(C);
+
+	ListBase ctx_objects;
+	CollectionPointerLink *ctx_ob_dst;
+
+	bool changed = false;
+
+	const int data_type = RNA_enum_get(op->ptr, "data_type");
+	const bool use_create = RNA_boolean_get(op->ptr, "use_create");
+
+	const int map_vert_mode = RNA_enum_get(op->ptr, "vert_mapping");
+	const int map_edge_mode = RNA_enum_get(op->ptr, "edge_mapping");
+	const int map_loop_mode = RNA_enum_get(op->ptr, "loop_mapping");
+	const int map_poly_mode = RNA_enum_get(op->ptr, "poly_mapping");
+
+	const bool use_object_transform = RNA_boolean_get(op->ptr, "use_object_transform");
+	const bool use_max_distance = RNA_boolean_get(op->ptr, "use_max_distance");
+	const float max_distance = use_max_distance ? RNA_float_get(op->ptr, "max_distance") : FLT_MAX;
+	const float ray_radius = RNA_float_get(op->ptr, "ray_radius");
+	const float islands_precision = RNA_float_get(op->ptr, "islands_precision");
+
+	const int layers_src = RNA_enum_get(op->ptr, "layers_select_src");
+	const int layers_dst = RNA_enum_get(op->ptr, "layers_select_dst");
+	int layers_select_src[DT_MULTILAYER_INDEX_MAX] = {0};
+	int layers_select_dst[DT_MULTILAYER_INDEX_MAX] = {0};
+	const int fromto_idx = BKE_object_data_transfer_dttype_to_srcdst_index(data_type);
+
+	const int mix_mode = RNA_enum_get(op->ptr, "mix_mode");
+	const float mix_factor = RNA_float_get(op->ptr, "mix_factor");
+
+	SpaceTransform space_transform_data;
+	SpaceTransform *space_transform = use_object_transform ? &space_transform_data : NULL;
+
+	if (fromto_idx != DT_MULTILAYER_INDEX_INVALID) {
+		layers_select_src[fromto_idx] = layers_src;
+		layers_select_dst[fromto_idx] = layers_dst;
+	}
+
+	data_transfer_exec_preprocess_objects(C, op, ob_src, &ctx_objects);
+
+	for (ctx_ob_dst = ctx_objects.first; ctx_ob_dst; ctx_ob_dst = ctx_ob_dst->next) {
+		Object *ob_dst = ctx_ob_dst->ptr.data;
+		if (data_transfer_exec_is_object_valid(op, ob_src, ob_dst)) {
+			if (space_transform) {
+				BLI_SPACE_TRANSFORM_SETUP(space_transform, ob_dst, ob_src);
+			}
+
+			if (BKE_object_data_transfer_mesh(
+			        scene, ob_src, ob_dst, data_type, use_create,
+			        map_vert_mode, map_edge_mode, map_loop_mode, map_poly_mode,
+			        space_transform, max_distance, ray_radius, islands_precision,
+			        layers_select_src, layers_select_dst,
+			        mix_mode, mix_factor, NULL, false, op->reports))
+			{
+				changed = true;
+			}
+		}
+	}
+
+	BLI_freelistN(&ctx_objects);
+
+#if 0  /* TODO */
+	/* Note: issue with that is that if canceled, operator cannot be redone... Nasty in our case. */
+	return changed ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+#else
+	return OPERATOR_FINISHED;
+#endif
+}
+
+/* Used by both OBJECT_OT_data_transfer and OBJECT_OT_datalayout_transfer */
+static int data_transfer_poll(bContext *C)
+{
+	Object *ob = ED_object_context(C);
+	ID *data = (ob) ? ob->data : NULL;
+	return (ob && !ob->id.lib && ob->type == OB_MESH && data && !data->lib);
+}
+
+/* Used by both OBJECT_OT_data_transfer and OBJECT_OT_datalayout_transfer */
+static bool data_transfer_draw_check_prop(PointerRNA *ptr, PropertyRNA *prop)
+{
+	PropertyRNA *prop_other;
+
+	const char *prop_id = RNA_property_identifier(prop);
+	const int data_type = RNA_enum_get(ptr, "data_type");
+	bool use_max_distance = false;
+	bool use_modifier = false;
+
+	if ((prop_other = RNA_struct_find_property(ptr, "use_max_distance"))) {
+		use_max_distance = RNA_property_boolean_get(ptr, prop_other);
+	}
+	if ((prop_other = RNA_struct_find_property(ptr, "modifier"))) {
+		use_modifier = RNA_property_is_set(ptr, prop_other);
+	}
+
+	if (STREQ(prop_id, "modifier")) {
+		return use_modifier;
+	}
+
+	if (use_modifier) {
+		/* Hide everything but 'modifier' property, if set. */
+		return false;
+	}
+
+	if (STREQ(prop_id, "max_distance") && !use_max_distance) {
+		return false;
+	}
+	if (STREQ(prop_id, "islands_precision") && !DT_DATATYPE_IS_LOOP(data_type)) {
+		return false;
+	}
+
+	if (STREQ(prop_id, "vert_mapping") && !DT_DATATYPE_IS_VERT(data_type)) {
+		return false;
+	}
+	if (STREQ(prop_id, "edge_mapping") && !DT_DATATYPE_IS_EDGE(data_type)) {
+		return false;
+	}
+	if (STREQ(prop_id, "loop_mapping") && !DT_DATATYPE_IS_LOOP(data_type)) {
+		return false;
+	}
+	if (STREQ(prop_id, "poly_mapping") && !DT_DATATYPE_IS_POLY(data_type)) {
+		return false;
+	}
+
+	if ((STREQ(prop_id, "layers_select_src") || STREQ(prop_id, "layers_select_dst")) &&
+	    !DT_DATATYPE_IS_MULTILAYERS(data_type))
+	{
+		return false;
+	}
+
+	/* Else, show it! */
+	return true;
+}
+
+/* Used by both OBJECT_OT_data_transfer and OBJECT_OT_datalayout_transfer */
+static void data_transfer_ui(bContext *C, wmOperator *op)
+{
+	uiLayout *layout = op->layout;
+	wmWindowManager *wm = CTX_wm_manager(C);
+	PointerRNA ptr;
+
+	RNA_pointer_create(&wm->id, op->type->srna, op->properties, &ptr);
+
+	/* Main auto-draw call */
+	uiDefAutoButsRNA(layout, &ptr, data_transfer_draw_check_prop, '\0');
+}
+
+/* transfers weight from active to selected */
+void OBJECT_OT_data_transfer(wmOperatorType *ot)
+{
+	PropertyRNA *prop;
+
+	/* Identifiers.*/
+	ot->name = "Transfer Mesh Data";
+	ot->idname = "OBJECT_OT_data_transfer";
+	ot->description = "Transfer data layer(s) (weights, edge sharp, ...) from active to selected meshes";
+
+	/* API callbacks.*/
+	ot->poll = data_transfer_poll;
+	ot->invoke = WM_menu_invoke;
+	ot->exec = data_transfer_exec;
+	ot->check = data_transfer_check;
+	ot->ui = data_transfer_ui;
+
+	/* Flags.*/
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+	/* Properties.*/
+	/* Data type to transfer. */
+	ot->prop = RNA_def_enum(ot->srna, "data_type", DT_layer_items, 0, "Data Type", "Which data to transfer");
+	RNA_def_boolean(ot->srna, "use_create", true, "Create Data", "Add data layers on destination meshes if needed");
+
+	/* Mapping methods. */
+	RNA_def_enum(ot->srna, "vert_mapping", DT_method_vertex_items, MREMAP_MODE_VERT_NEAREST, "Vertex Mapping",
+	             "Method used to map source vertices to destination ones");
+	RNA_def_enum(ot->srna, "edge_mapping", DT_method_edge_items, MREMAP_MODE_EDGE_NEAREST, "Edge Mapping",
+	             "Method used to map source edges to destination ones");
+	RNA_def_enum(ot->srna, "loop_mapping", DT_method_loop_items, MREMAP_MODE_LOOP_NEAREST_POLYNOR,
+	             "Face Corner Mapping", "Method used to map source faces' corners to destination ones");
+	RNA_def_enum(ot->srna, "poly_mapping", DT_method_poly_items, MREMAP_MODE_POLY_NEAREST, "Face Mapping",
+	             "Method used to map source faces to destination ones");
+
+	/* Mapping options and filtering. */
+	RNA_def_boolean(ot->srna, "use_object_transform", true, "Object Transform",
+	                "Evaluate source and destination meshes in their respective object spaces");
+	RNA_def_boolean(ot->srna, "use_max_distance", false, "Only Neighbor Geometry",
+	                "Source elements must be closer than given distance from destination one");
+	prop = RNA_def_float(ot->srna, "max_distance", 1.0f, 0.0f, FLT_MAX, "Max Distance",
+	                     "Maximum allowed distance between source and destination element, for non-topology mappings",
+	                     0.0f, 100.0f);
+	RNA_def_property_subtype(prop, PROP_DISTANCE);
+	prop = RNA_def_float(ot->srna, "ray_radius", 0.0f, 0.0f, FLT_MAX, "Ray Radius",
+	                     "'Width' of rays (especially useful when raycasting against vertices or edges)",
+	                     0.0f, 10.0f);
+	RNA_def_property_subtype(prop, PROP_DISTANCE);
+	prop = RNA_def_float(ot->srna, "islands_precision", 0.1f, 0.0f, 10.0f, "Islands Precision",
+	                     "Factor controlling precision of islands handling (the higher, the better the results)",
+	                     0.0f, 1.0f);
+	RNA_def_property_subtype(prop, PROP_FACTOR);
+
+	/* How to handle multi-layers types of data. */
+	prop = RNA_def_enum(ot->srna, "layers_select_src", DT_layers_select_src_items, DT_LAYERS_ACTIVE_SRC,
+	                    "Source Layers Selection", "Which layers to transfer, in case of multi-layers types");
+	RNA_def_property_enum_funcs_runtime(prop, NULL, NULL, dt_layers_select_src_itemf);
+
+	prop = RNA_def_enum(ot->srna, "layers_select_dst", DT_layers_select_dst_items, DT_LAYERS_ACTIVE_DST,
+	                    "Destination Layers Matching", "How to match source and destination layers");
+	RNA_def_property_enum_funcs_runtime(prop, NULL, NULL, dt_layers_select_dst_itemf);
+
+	prop = RNA_def_enum(ot->srna, "mix_mode", DT_mix_mode_items, CDT_MIX_TRANSFER, "Mix Mode",
+	                   "How to affect destination elements with source values");
+	RNA_def_property_enum_funcs_runtime(prop, NULL, NULL, dt_mix_mode_itemf);
+	RNA_def_float(ot->srna, "mix_factor", 1.0f, 0.0f, 1.0f, "Mix Factor",
+	              "Factor to use when applying data to destination (exact behavior depends on mix mode)", 0.0f, 1.0f);
+}
+
+/******************************************************************************/
+/* Note: This operator is hybrid, it can work as a usual standalone Object operator,
+ *       or as a DataTransfer modifier tool.
+ */
+
+static int datalayout_transfer_poll(bContext *C)
+{
+	return (data_transfer_poll(C));
+}
+
+static int datalayout_transfer_exec(bContext *C, wmOperator *op)
+{
+	Scene *scene = CTX_data_scene(C);
+	Object *ob_act = ED_object_active_context(C);
+
+	{
+		Object *ob_src = ob_act;
+
+		ListBase ctx_objects;
+		CollectionPointerLink *ctx_ob_dst;
+
+		const int data_type = RNA_enum_get(op->ptr, "data_type");
+		const bool use_delete = RNA_boolean_get(op->ptr, "use_delete");
+
+		const int layers_src = RNA_enum_get(op->ptr, "layers_select_src");
+		const int layers_dst = RNA_enum_get(op->ptr, "layers_select_dst");
+		int layers_select_src[DT_MULTILAYER_INDEX_MAX] = {0};
+		int layers_select_dst[DT_MULTILAYER_INDEX_MAX] = {0};
+		const int fromto_idx = BKE_object_data_transfer_dttype_to_srcdst_index(data_type);
+
+		if (fromto_idx != DT_MULTILAYER_INDEX_INVALID) {
+			layers_select_src[fromto_idx] = layers_src;
+			layers_select_dst[fromto_idx] = layers_dst;
+		}
+
+		data_transfer_exec_preprocess_objects(C, op, ob_src, &ctx_objects);
+
+		for (ctx_ob_dst = ctx_objects.first; ctx_ob_dst; ctx_ob_dst = ctx_ob_dst->next) {
+			Object *ob_dst = ctx_ob_dst->ptr.data;
+			if (data_transfer_exec_is_object_valid(op, ob_src, ob_dst)) {
+				BKE_object_data_transfer_layout(scene, ob_src, ob_dst, data_type, use_delete,
+				                                layers_select_src, layers_select_dst);
+			}
+		}
+
+		BLI_freelistN(&ctx_objects);
+	}
+
+	return OPERATOR_FINISHED;
+}
+
+static int datalayout_transfer_invoke(bContext *C, wmOperator *op, const wmEvent *event)
+{
+	return WM_menu_invoke(C, op, event);
+}
+
+void OBJECT_OT_datalayout_transfer(wmOperatorType *ot)
+{
+	PropertyRNA *prop;
+
+	ot->name = "Transfer Mesh Datalayout";
+	ot->description = "Transfer layout of data layer(s) from active to selected meshes";
+	ot->idname = "OBJECT_OT_datalayout_transfer";
+
+	ot->poll = datalayout_transfer_poll;
+	ot->invoke = datalayout_transfer_invoke;
+	ot->exec = datalayout_transfer_exec;
+	ot->check = data_transfer_check;
+	ot->ui = data_transfer_ui;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+	/* Properties.*/
+	/* edit_modifier_properties(ot); */
+
+	/* Data type to transfer. */
+	ot->prop = RNA_def_enum(ot->srna, "data_type", DT_layer_items, 0, "Data Type", "Which data to transfer");
+	RNA_def_boolean(ot->srna, "use_delete", false, "Exact Match",
+	                "Also delete some data layers from destination if necessary, so that it matches exactly source");
+
+	/* How to handle multi-layers types of data. */
+	prop = RNA_def_enum(ot->srna, "layers_select_src", DT_layers_select_src_items, DT_LAYERS_ACTIVE_SRC,
+	                    "Source Layers Selection", "Which layers to transfer, in case of multi-layers types");
+	RNA_def_property_enum_funcs_runtime(prop, NULL, NULL, dt_layers_select_src_itemf);
+
+	prop = RNA_def_enum(ot->srna, "layers_select_dst", DT_layers_select_dst_items, DT_LAYERS_ACTIVE_DST,
+	                    "Destination Layers Matching", "How to match source and destination layers");
+	RNA_def_property_enum_funcs_runtime(prop, NULL, NULL, dt_layers_select_dst_itemf);
+}
diff --git a/source/blender/editors/object/object_intern.h b/source/blender/editors/object/object_intern.h
index 6fa3caa6172..bcf77d819fe 100644
--- a/source/blender/editors/object/object_intern.h
+++ b/source/blender/editors/object/object_intern.h
@@ -266,5 +266,9 @@ void OBJECT_OT_lod_remove(struct wmOperatorType *ot);
 /* object_random.c */
 void OBJECT_OT_vertex_random(struct wmOperatorType *ot);
 
+/* object_transfer_data.c */
+void OBJECT_OT_data_transfer(struct wmOperatorType *ot);
+void OBJECT_OT_datalayout_transfer(struct wmOperatorType *ot);
+
 #endif /* __OBJECT_INTERN_H__ */
 
diff --git a/source/blender/editors/object/object_ops.c b/source/blender/editors/object/object_ops.c
index 2062b85fe4b..5189594c919 100644
--- a/source/blender/editors/object/object_ops.c
+++ b/source/blender/editors/object/object_ops.c
@@ -249,6 +249,9 @@ void ED_operatortypes_object(void)
 	WM_operatortype_append(OBJECT_OT_lod_remove);
 
 	WM_operatortype_append(OBJECT_OT_vertex_random);
+
+	WM_operatortype_append(OBJECT_OT_data_transfer);
+	WM_operatortype_append(OBJECT_OT_datalayout_transfer);
 }
 
 void ED_operatormacros_object(void)
@@ -420,6 +423,10 @@ void ED_keymap_object(wmKeyConfig *keyconf)
 	
 	WM_keymap_add_menu(keymap, "VIEW3D_MT_object_specials", WKEY, KM_PRESS, 0, 0);
 
+	WM_keymap_verify_item(keymap, "OBJECT_OT_data_transfer", TKEY, KM_PRESS, KM_SHIFT | KM_CTRL, 0);
+	/* XXX No more available 'T' shortcuts... :/ */
+	/* WM_keymap_verify_item(keymap, "OBJECT_OT_datalayout_transfer", TKEY, KM_PRESS, KM_SHIFT | KM_CTRL, 0); */
+
 	for (i = 0; i <= 5; i++) {
 		kmi = WM_keymap_add_item(keymap, "OBJECT_OT_subdivision_set", ZEROKEY + i, KM_PRESS, KM_CTRL, 0);
 		RNA_int_set(kmi->ptr, "level", i);