Surface Deform Modifier (SDef)

Implementation of the SDef modifier, which allows meshes to be bound by
surface, thus allowing things such as cloth simulation proxies.

User documentation: https://wiki.blender.org/index.php/User:Lucarood/SurfaceDeform

Reviewers: mont29, sergey

Subscribers: Severin, dfelinto, plasmasolutions, kjym3

Differential Revision: https://developer.blender.org/D2462

14 files changed, 1404 insertions, 0 deletions

diff --git a/release/scripts/startup/bl_ui/properties_data_modifier.py b/release/scripts/startup/bl_ui/properties_data_modifier.py
index b24b574f37b..d62c20d4589 100644
--- a/release/scripts/startup/bl_ui/properties_data_modifier.py
+++ b/release/scripts/startup/bl_ui/properties_data_modifier.py
@@ -951,6 +951,20 @@ class DATA_PT_modifiers(ModifierButtonsPanel, Panel):
     def SURFACE(self, layout, ob, md):
         layout.label(text="Settings are inside the Physics tab")
 
+    def SURFACE_DEFORM(self, layout, ob, md):
+        col = layout.column()
+        col.active = not md.is_bound
+
+        col.prop(md, "target")
+        col.prop(md, "falloff")
+
+        layout.separator()
+
+        if md.is_bound:
+            layout.operator("object.surfacedeform_bind", text="Unbind")
+        else:
+            layout.operator("object.surfacedeform_bind", text="Bind")
+
     def UV_PROJECT(self, layout, ob, md):
         split = layout.split()
 
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 7ea79fc5557..638f877c841 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -5317,6 +5317,37 @@ static void direct_link_modifiers(FileData *fd, ListBase *lb)
 			MeshSeqCacheModifierData *msmcd = (MeshSeqCacheModifierData *)md;
 			msmcd->reader = NULL;
 		}
+		else if (md->type == eModifierType_SurfaceDeform) {
+			SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)md;
+
+			smd->verts = newdataadr(fd, smd->verts);
+
+			if (smd->verts) {
+				for (int i = 0; i < smd->numverts; i++) {
+					smd->verts[i].binds = newdataadr(fd, smd->verts[i].binds);
+
+					if (smd->verts[i].binds) {
+						for (int j = 0; j < smd->verts[i].numbinds; j++) {
+							smd->verts[i].binds[j].vert_inds = newdataadr(fd, smd->verts[i].binds[j].vert_inds);
+							smd->verts[i].binds[j].vert_weights = newdataadr(fd, smd->verts[i].binds[j].vert_weights);
+
+							if (fd->flags & FD_FLAGS_SWITCH_ENDIAN) {
+								if (smd->verts[i].binds[j].vert_inds)
+									BLI_endian_switch_uint32_array(smd->verts[i].binds[j].vert_inds, smd->verts[i].binds[j].numverts);
+
+								if (smd->verts[i].binds[j].vert_weights) {
+									if (smd->verts[i].binds[j].mode == MOD_SDEF_MODE_CENTROID ||
+									    smd->verts[i].binds[j].mode == MOD_SDEF_MODE_LOOPTRI)
+										BLI_endian_switch_float_array(smd->verts[i].binds[j].vert_weights, 3);
+									else
+										BLI_endian_switch_float_array(smd->verts[i].binds[j].vert_weights, smd->verts[i].binds[j].numverts);
+								}
+							}
+						}
+					}
+				}
+			}
+		}
 	}
 }
 
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index 38a032f4907..01d07e0d774 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -1837,6 +1837,32 @@ static void write_modifiers(WriteData *wd, ListBase *modbase)
 				writedata(wd, DATA, sizeof(float[3]) * csmd->bind_coords_num, csmd->bind_coords);
 			}
 		}
+		else if (md->type == eModifierType_SurfaceDeform) {
+			SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)md;
+
+			writestruct(wd, DATA, SDefVert, smd->numverts, smd->verts);
+
+			if (smd->verts) {
+				for (int i = 0; i < smd->numverts; i++) {
+					writestruct(wd, DATA, SDefBind, smd->verts[i].numbinds, smd->verts[i].binds);
+
+					if (smd->verts[i].binds) {
+						for (int j = 0; j < smd->verts[i].numbinds; j++) {
+							writedata(wd, DATA, sizeof(int) * smd->verts[i].binds[j].numverts, smd->verts[i].binds[j].vert_inds);
+
+							if (smd->verts[i].binds[j].mode == MOD_SDEF_MODE_CENTROID ||
+							    smd->verts[i].binds[j].mode == MOD_SDEF_MODE_LOOPTRI)
+							{
+								writedata(wd, DATA, sizeof(float) * 3, smd->verts[i].binds[j].vert_weights);
+							}
+							else {
+								writedata(wd, DATA, sizeof(float) * smd->verts[i].binds[j].numverts, smd->verts[i].binds[j].vert_weights);
+							}
+						}
+					}
+				}
+			}
+		}
 	}
 }
 
diff --git a/source/blender/editors/object/object_intern.h b/source/blender/editors/object/object_intern.h
index 9710e4f843d..b8957bdedf9 100644
--- a/source/blender/editors/object/object_intern.h
+++ b/source/blender/editors/object/object_intern.h
@@ -186,6 +186,7 @@ void OBJECT_OT_skin_loose_mark_clear(struct wmOperatorType *ot);
 void OBJECT_OT_skin_radii_equalize(struct wmOperatorType *ot);
 void OBJECT_OT_skin_armature_create(struct wmOperatorType *ot);
 void OBJECT_OT_laplaciandeform_bind(struct wmOperatorType *ot);
+void OBJECT_OT_surfacedeform_bind(struct wmOperatorType *ot);
 
 /* object_constraint.c */
 void OBJECT_OT_constraint_add(struct wmOperatorType *ot);
diff --git a/source/blender/editors/object/object_modifier.c b/source/blender/editors/object/object_modifier.c
index 06f495fb9f1..38df1116cd3 100644
--- a/source/blender/editors/object/object_modifier.c
+++ b/source/blender/editors/object/object_modifier.c
@@ -2294,3 +2294,63 @@ void OBJECT_OT_laplaciandeform_bind(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
 	edit_modifier_properties(ot);
 }
+
+/************************ sdef bind operator *********************/
+
+static int surfacedeform_bind_poll(bContext *C)
+{
+	if (edit_modifier_poll_generic(C, &RNA_SurfaceDeformModifier, 0)) {
+		PointerRNA ptr = CTX_data_pointer_get_type(C, "modifier", &RNA_SurfaceDeformModifier);
+		SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)ptr.data;
+
+		return ((smd != NULL) && (smd->target != NULL));
+	}
+
+	return 0;
+}
+
+static int surfacedeform_bind_exec(bContext *C, wmOperator *op)
+{
+	Object *ob = ED_object_active_context(C);
+	SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)edit_modifier_property_get(op, ob, eModifierType_SurfaceDeform);
+
+	if (!smd)
+		return OPERATOR_CANCELLED;
+
+	if (smd->flags & MOD_SDEF_BIND) {
+		smd->flags &= ~MOD_SDEF_BIND;
+	}
+	else if (smd->target) {
+		smd->flags |= MOD_SDEF_BIND;
+	}
+
+	DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
+	WM_event_add_notifier(C, NC_OBJECT | ND_MODIFIER, ob);
+
+	return OPERATOR_FINISHED;
+}
+
+static int surfacedeform_bind_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
+{
+	if (edit_modifier_invoke_properties(C, op))
+		return surfacedeform_bind_exec(C, op);
+	else
+		return OPERATOR_CANCELLED;
+}
+
+void OBJECT_OT_surfacedeform_bind(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Surface Deform Bind";
+	ot->description = "Bind mesh to target in surface deform modifier";
+	ot->idname = "OBJECT_OT_surfacedeform_bind";
+
+	/* api callbacks */
+	ot->poll = surfacedeform_bind_poll;
+	ot->invoke = surfacedeform_bind_invoke;
+	ot->exec = surfacedeform_bind_exec;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
+	edit_modifier_properties(ot);
+}
diff --git a/source/blender/editors/object/object_ops.c b/source/blender/editors/object/object_ops.c
index 7e7e1ef182c..5fe5a884354 100644
--- a/source/blender/editors/object/object_ops.c
+++ b/source/blender/editors/object/object_ops.c
@@ -255,6 +255,7 @@ void ED_operatortypes_object(void)
 
 	WM_operatortype_append(OBJECT_OT_data_transfer);
 	WM_operatortype_append(OBJECT_OT_datalayout_transfer);
+	WM_operatortype_append(OBJECT_OT_surfacedeform_bind);
 }
 
 void ED_operatormacros_object(void)
diff --git a/source/blender/editors/space_outliner/outliner_draw.c b/source/blender/editors/space_outliner/outliner_draw.c
index 99242fd12f9..684a1f9fd67 100644
--- a/source/blender/editors/space_outliner/outliner_draw.c
+++ b/source/blender/editors/space_outliner/outliner_draw.c
@@ -1126,6 +1126,7 @@ static void tselem_draw_icon(uiBlock *block, int xmax, float x, float y, TreeSto
 					case eModifierType_Cast:
 						UI_icon_draw(x, y, ICON_MOD_CAST); break;
 					case eModifierType_MeshDeform:
+					case eModifierType_SurfaceDeform:
 						UI_icon_draw(x, y, ICON_MOD_MESHDEFORM); break;
 					case eModifierType_Bevel:
 						UI_icon_draw(x, y, ICON_MOD_BEVEL); break;
diff --git a/source/blender/makesdna/DNA_modifier_types.h b/source/blender/makesdna/DNA_modifier_types.h
index f95533a88f9..0c17909db23 100644
--- a/source/blender/makesdna/DNA_modifier_types.h
+++ b/source/blender/makesdna/DNA_modifier_types.h
@@ -86,6 +86,7 @@ typedef enum ModifierType {
 	eModifierType_NormalEdit        = 50,
 	eModifierType_CorrectiveSmooth  = 51,
 	eModifierType_MeshSequenceCache = 52,
+	eModifierType_SurfaceDeform     = 53,
 	NUM_MODIFIER_TYPES
 } ModifierType;
 
@@ -1570,6 +1571,45 @@ enum {
 	MOD_MESHSEQ_READ_COLOR = (1 << 3),
 };
 
+typedef struct SDefBind {
+	unsigned int *vert_inds;
+	unsigned int numverts;
+	int mode;
+	float *vert_weights;
+	float normal_dist;
+	float influence;
+} SDefBind;
+
+typedef struct SDefVert {
+	SDefBind *binds;
+	unsigned int numbinds;
+	char pad[4];
+} SDefVert;
+
+typedef struct SurfaceDeformModifierData {
+	ModifierData modifier;
+
+	struct Object *target;	/* bind target object */
+	SDefVert *verts;		/* vertex bind data */
+	float falloff;
+	unsigned int numverts, numpoly;
+	int flags;
+} SurfaceDeformModifierData;
+
+/* Surface Deform modifier flags */
+enum {
+	MOD_SDEF_BIND = (1 << 0),
+	MOD_SDEF_USES_LOOPTRI = (1 << 1),
+	MOD_SDEF_HAS_CONCAVE = (1 << 2),
+};
+
+/* Surface Deform vertex bind modes */
+enum {
+	MOD_SDEF_MODE_LOOPTRI = 0,
+	MOD_SDEF_MODE_NGON = 1,
+	MOD_SDEF_MODE_CENTROID = 2,
+};
+
 #define MOD_MESHSEQ_READ_ALL \
 	(MOD_MESHSEQ_READ_VERT | MOD_MESHSEQ_READ_POLY | MOD_MESHSEQ_READ_UV | MOD_MESHSEQ_READ_COLOR)
 
diff --git a/source/blender/makesrna/RNA_access.h b/source/blender/makesrna/RNA_access.h
index 66e6f30feeb..f9aaec69ce7 100644
--- a/source/blender/makesrna/RNA_access.h
+++ b/source/blender/makesrna/RNA_access.h
@@ -598,6 +598,7 @@ extern StructRNA RNA_StucciTexture;
 extern StructRNA RNA_SubsurfModifier;
 extern StructRNA RNA_SunLamp;
 extern StructRNA RNA_SurfaceCurve;
+extern StructRNA RNA_SurfaceDeformModifier;
 extern StructRNA RNA_SurfaceModifier;
 extern StructRNA RNA_TexMapping;
 extern StructRNA RNA_Text;
diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index c4f0db38a16..47c4b425155 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -105,6 +105,7 @@ EnumPropertyItem rna_enum_object_modifier_type_items[] = {
 	{eModifierType_Shrinkwrap, "SHRINKWRAP", ICON_MOD_SHRINKWRAP, "Shrinkwrap", ""},
 	{eModifierType_SimpleDeform, "SIMPLE_DEFORM", ICON_MOD_SIMPLEDEFORM, "Simple Deform", ""},
 	{eModifierType_Smooth, "SMOOTH", ICON_MOD_SMOOTH, "Smooth", ""},
+	{eModifierType_SurfaceDeform, "SURFACE_DEFORM", ICON_MOD_MESHDEFORM, "Surface Deform", ""},
 	{eModifierType_Warp, "WARP", ICON_MOD_WARP, "Warp", ""},
 	{eModifierType_Wave, "WAVE", ICON_MOD_WAVE, "Wave", ""},
 	{0, "", 0, N_("Simulate"), ""},
@@ -408,6 +409,8 @@ static StructRNA *rna_Modifier_refine(struct PointerRNA *ptr)
 			return &RNA_CorrectiveSmoothModifier;
 		case eModifierType_MeshSequenceCache:
 			return &RNA_MeshSequenceCacheModifier;
+		case eModifierType_SurfaceDeform:
+			return &RNA_SurfaceDeformModifier;
 		/* Default */
 		case eModifierType_None:
 		case eModifierType_ShapeKey:
@@ -573,6 +576,7 @@ RNA_MOD_OBJECT_SET(MeshDeform, object, OB_MESH);
 RNA_MOD_OBJECT_SET(NormalEdit, target, OB_EMPTY);
 RNA_MOD_OBJECT_SET(Shrinkwrap, target, OB_MESH);
 RNA_MOD_OBJECT_SET(Shrinkwrap, auxTarget, OB_MESH);
+RNA_MOD_OBJECT_SET(SurfaceDeform, target, OB_MESH);
 
 static void rna_HookModifier_object_set(PointerRNA *ptr, PointerRNA value)
 {
@@ -1131,6 +1135,11 @@ static int rna_CorrectiveSmoothModifier_is_bind_get(PointerRNA *ptr)
 	return (csmd->bind_coords != NULL);
 }
 
+static int rna_SurfaceDeformModifier_is_bound_get(PointerRNA *ptr)
+{
+	return (((SurfaceDeformModifierData *)ptr->data)->verts != NULL);
+}
+
 static void rna_MeshSequenceCache_object_path_update(Main *bmain, Scene *scene, PointerRNA *ptr)
 {
 #ifdef WITH_ALEMBIC
@@ -4702,6 +4711,33 @@ static void rna_def_modifier_normaledit(BlenderRNA *brna)
 	RNA_def_property_update(prop, 0, "rna_Modifier_update");
 }
 
+static void rna_def_modifier_surfacedeform(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+
+	srna = RNA_def_struct(brna, "SurfaceDeformModifier", "Modifier");
+	RNA_def_struct_ui_text(srna, "SurfaceDeform Modifier", "blablabla");
+	RNA_def_struct_sdna(srna, "SurfaceDeformModifierData");
+	RNA_def_struct_ui_icon(srna, ICON_MOD_MESHDEFORM);
+
+	prop = RNA_def_property(srna, "target", PROP_POINTER, PROP_NONE);
+	RNA_def_property_ui_text(prop, "Target", "Mesh object to deform with");
+	RNA_def_property_pointer_funcs(prop, NULL, "rna_SurfaceDeformModifier_target_set", NULL, "rna_Mesh_object_poll");
+	RNA_def_property_flag(prop, PROP_EDITABLE | PROP_ID_SELF_CHECK);
+	RNA_def_property_update(prop, 0, "rna_Modifier_dependency_update");
+
+	prop = RNA_def_property(srna, "falloff", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_range(prop, 2.0f, 16.0f);
+	RNA_def_property_ui_text(prop, "Interpolation falloff", "Controls how much nearby polygons influence deformation");
+	RNA_def_property_update(prop, 0, "rna_Modifier_update");
+
+	prop = RNA_def_property(srna, "is_bound", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_funcs(prop, "rna_SurfaceDeformModifier_is_bound_get", NULL);
+	RNA_def_property_ui_text(prop, "Bound", "Whether geometry has been bound to target mesh");
+	RNA_def_property_clear_flag(prop, PROP_EDITABLE);
+}
+
 void RNA_def_modifier(BlenderRNA *brna)
 {
 	StructRNA *srna;
@@ -4819,6 +4855,7 @@ void RNA_def_modifier(BlenderRNA *brna)
 	rna_def_modifier_datatransfer(brna);
 	rna_def_modifier_normaledit(brna);
 	rna_def_modifier_meshseqcache(brna);
+	rna_def_modifier_surfacedeform(brna);
 }
 
 #endif
diff --git a/source/blender/modifiers/CMakeLists.txt b/source/blender/modifiers/CMakeLists.txt
index bacfc177432..ad2b862141c 100644
--- a/source/blender/modifiers/CMakeLists.txt
+++ b/source/blender/modifiers/CMakeLists.txt
@@ -93,6 +93,7 @@ set(SRC
 	intern/MOD_solidify.c
 	intern/MOD_subsurf.c
 	intern/MOD_surface.c
+	intern/MOD_surfacedeform.c
 	intern/MOD_triangulate.c
 	intern/MOD_util.c
 	intern/MOD_uvwarp.c
diff --git a/source/blender/modifiers/MOD_modifiertypes.h b/source/blender/modifiers/MOD_modifiertypes.h
index 4c881445893..bf121af2bd1 100644
--- a/source/blender/modifiers/MOD_modifiertypes.h
+++ b/source/blender/modifiers/MOD_modifiertypes.h
@@ -85,6 +85,7 @@ extern ModifierTypeInfo modifierType_DataTransfer;
 extern ModifierTypeInfo modifierType_NormalEdit;
 extern ModifierTypeInfo modifierType_CorrectiveSmooth;
 extern ModifierTypeInfo modifierType_MeshSequenceCache;
+extern ModifierTypeInfo modifierType_SurfaceDeform;
 
 /* MOD_util.c */
 void modifier_type_init(ModifierTypeInfo *types[]);
diff --git a/source/blender/modifiers/intern/MOD_surfacedeform.c b/source/blender/modifiers/intern/MOD_surfacedeform.c
new file mode 100644
index 00000000000..5e852e84516
--- /dev/null
+++ b/source/blender/modifiers/intern/MOD_surfacedeform.c
@@ -0,0 +1,1189 @@
+#include "DNA_object_types.h"
+#include "DNA_scene_types.h"
+
+#include "BLI_alloca.h"
+#include "BLI_math.h"
+#include "BLI_math_geom.h"
+#include "BLI_task.h"
+
+#include "BKE_cdderivedmesh.h"
+#include "BKE_editmesh.h"
+#include "BKE_library_query.h"
+#include "BKE_modifier.h"
+
+#include "depsgraph_private.h"
+
+#include "MEM_guardedalloc.h"
+
+#include "MOD_util.h"
+
+typedef struct SDefAdjacency {
+	struct SDefAdjacency *next;
+	unsigned int index;
+} SDefAdjacency;
+
+typedef struct SDefAdjacencyArray {
+	SDefAdjacency *first;
+	unsigned int num; /* Careful, this is twice the number of polygons (avoids an extra loop) */
+} SDefAdjacencyArray;
+
+typedef struct SDefEdgePolys {
+	unsigned int polys[2], num;
+} SDefEdgePolys;
+
+typedef struct SDefBindCalcData {
+	BVHTreeFromMesh * const treeData;
+	const SDefAdjacencyArray * const vert_edges;
+	const SDefEdgePolys * const edge_polys;
+	SDefVert * const bind_verts;
+	const MLoopTri * const looptri;
+	const MPoly * const mpoly;
+	const MEdge * const medge;
+	const MLoop * const mloop;
+	const MVert * const mvert;
+	float (* const vertexCos)[3];
+	const float falloff;
+	int success;
+} SDefBindCalcData;
+
+typedef struct SDefBindPoly {
+	float (*coords)[3];
+	float (*coords_v2)[2];
+	float point_v2[2];
+	float weight_angular;
+	float weight_dist_proj;
+	float weight_dist;
+	float weight;
+	float scales[2];
+	float centroid[3];
+	float centroid_v2[2];
+	float normal[3];
+	float cent_edgemid_vecs_v2[2][2];
+	float edgemid_angle;
+	float point_edgemid_angles[2];
+	float corner_edgemid_angles[2];
+	float dominant_angle_weight;
+	unsigned int index;
+	unsigned int numverts;
+	unsigned int loopstart;
+	unsigned int edge_inds[2];
+	unsigned int edge_vert_inds[2];
+	unsigned int corner_ind;
+	unsigned int dominant_edge;
+	bool inside;
+} SDefBindPoly;
+
+typedef struct SDefBindWeightData {
+	SDefBindPoly *bind_polys;
+	unsigned int numpoly;
+	unsigned int numbinds;
+} SDefBindWeightData;
+
+typedef struct SDefDeformData {
+	const SDefVert * const bind_verts;
+	const MVert * const mvert;
+	float (* const vertexCos)[3];
+} SDefDeformData;
+
+/* Bind result values */
+enum {
+	MOD_SDEF_BIND_RESULT_SUCCESS = 1,
+	MOD_SDEF_BIND_RESULT_GENERIC_ERR = 0,
+	MOD_SDEF_BIND_RESULT_MEM_ERR = -1,
+	MOD_SDEF_BIND_RESULT_NONMANY_ERR = -2,
+	MOD_SDEF_BIND_RESULT_CONCAVE_ERR = -3,
+	MOD_SDEF_BIND_RESULT_OVERLAP_ERR = -4,
+};
+
+/* Infinite weight flags */
+enum {
+	MOD_SDEF_INFINITE_WEIGHT_ANGULAR = (1 << 0),
+	MOD_SDEF_INFINITE_WEIGHT_DIST_PROJ = (1 << 1),
+	MOD_SDEF_INFINITE_WEIGHT_DIST = (1 << 2),
+};
+
+static void initData(ModifierData *md)
+{
+	SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)md;
+	smd->target = NULL;
+	smd->verts = NULL;
+	smd->flags = 0;
+	smd->falloff = 4.0f;
+}
+
+static void freeData(ModifierData *md)
+{
+	SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)md;
+
+	if (smd->verts) {
+		for (int i = 0; i < smd->numverts; i++) {
+			if (smd->verts[i].binds) {
+				for (int j = 0; j < smd->verts[i].numbinds; j++) {
+					MEM_SAFE_FREE(smd->verts[i].binds[j].vert_inds);
+					MEM_SAFE_FREE(smd->verts[i].binds[j].vert_weights);
+				}
+
+				MEM_freeN(smd->verts[i].binds);
+			}
+		}
+
+		MEM_freeN(smd->verts);
+		smd->verts = NULL;
+	}
+}
+
+static void copyData(ModifierData *md, ModifierData *target)
+{
+	SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)md;
+	SurfaceDeformModifierData *tsmd = (SurfaceDeformModifierData *)target;
+
+	*tsmd = *smd;
+
+	if (smd->verts) {
+		tsmd->verts = MEM_dupallocN(smd->verts);
+
+		for (int i = 0; i < smd->numverts; i++) {
+			if (smd->verts[i].binds) {
+				tsmd->verts[i].binds = MEM_dupallocN(smd->verts[i].binds);
+
+				for (int j = 0; j < smd->verts[i].numbinds; j++) {
+					if (smd->verts[i].binds[j].vert_inds) {
+						tsmd->verts[i].binds[j].vert_inds = MEM_dupallocN(smd->verts[i].binds[j].vert_inds);
+					}
+
+					if (smd->verts[i].binds[j].vert_weights) {
+						tsmd->verts[i].binds[j].vert_weights = MEM_dupallocN(smd->verts[i].binds[j].vert_weights);
+					}
+				}
+			}
+		}
+	}
+}
+
+static void foreachObjectLink(ModifierData *md, Object *ob, ObjectWalkFunc walk, void *userData)
+{
+	SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)md;
+
+	walk(userData, ob, &smd->target, IDWALK_NOP);
+}
+
+static void updateDepgraph(ModifierData *md, DagForest *forest,
+                           struct Main *UNUSED(bmain),
+                           struct Scene *UNUSED(scene),
+                           Object *UNUSED(ob),
+                           DagNode *obNode)
+{
+	SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)md;
+
+	if (smd->target) {
+		DagNode *curNode = dag_get_node(forest, smd->target);
+
+		dag_add_relation(forest, curNode, obNode, DAG_RL_DATA_DATA, "Surface Deform Modifier");
+	}
+}
+
+static void updateDepsgraph(ModifierData *md,
+                            struct Main *UNUSED(bmain),
+                            struct Scene *UNUSED(scene),
+                            Object *UNUSED(ob),
+                            struct DepsNodeHandle *node)
+{
+	SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)md;
+	if (smd->target != NULL) {
+		DEG_add_object_relation(node, smd->target, DEG_OB_COMP_GEOMETRY, "Surface Deform Modifier");
+	}
+}
+
+static void freeAdjacencyMap(SDefAdjacencyArray * const vert_edges, SDefAdjacency * const adj_ref, SDefEdgePolys * const edge_polys)
+{
+	MEM_freeN(edge_polys);
+
+	MEM_freeN(adj_ref);
+
+	MEM_freeN(vert_edges);
+}
+
+static int buildAdjacencyMap(const MPoly *poly, const MEdge *edge, const MLoop * const mloop, const unsigned int numpoly, const unsigned int numedges,
+                              SDefAdjacencyArray * const vert_edges, SDefAdjacency *adj, SDefEdgePolys * const edge_polys)
+{
+	const MLoop *loop;
+
+	/* Fing polygons adjacent to edges */
+	for (int i = 0; i < numpoly; i++, poly++) {
+		loop = &mloop[poly->loopstart];
+
+		for (int j = 0; j < poly->totloop; j++, loop++) {
+			if (edge_polys[loop->e].num == 0) {
+				edge_polys[loop->e].polys[0] = i;
+				edge_polys[loop->e].polys[1] = -1;
+				edge_polys[loop->e].num++;
+			}
+			else if (edge_polys[loop->e].num == 1) {
+				edge_polys[loop->e].polys[1] = i;
+				edge_polys[loop->e].num++;
+			}
+			else {
+				return MOD_SDEF_BIND_RESULT_NONMANY_ERR;
+			}
+		}
+	}
+
+	/* Find edges adjacent to vertices */
+	for (int i = 0; i < numedges; i++, edge++) {
+		adj->next = vert_edges[edge->v1].first;
+		adj->index = i;
+		vert_edges[edge->v1].first = adj;
+		vert_edges[edge->v1].num += edge_polys[i].num;
+		adj++;
+
+		adj->next = vert_edges[edge->v2].first;
+		adj->index = i;
+		vert_edges[edge->v2].first = adj;
+		vert_edges[edge->v2].num += edge_polys[i].num;
+		adj++;
+	}
+
+	return MOD_SDEF_BIND_RESULT_SUCCESS;
+}
+
+BLI_INLINE void sortPolyVertsEdge(unsigned int *indices, const MLoop * const mloop, const unsigned int edge, const unsigned int num)
+{
+	bool found = false;
+
+	for (int i = 0; i < num; i++) {
+		if (mloop[i].e == edge) {
+			found = true;
+		}
+		if (found) {
+			*indices = mloop[i].v;
+			indices++;
+		}
+	}
+
+	/* Fill in remaining vertex indices that occur before the edge */
+	for (int i = 0; mloop[i].e != edge; i++) {
+		*indices = mloop[i].v;
+		indices++;
+	}
+}
+
+BLI_INLINE void sortPolyVertsTri(unsigned int *indices, const MLoop * const mloop, const unsigned int loopstart, const unsigned int num)
+{
+	for (int i = loopstart; i < num; i++) {
+		*indices = mloop[i].v;
+		indices++;
+	}
+
+	for (int i = 0; i < loopstart; i++) {
+		*indices = mloop[i].v;
+		indices++;
+	}
+}
+
+BLI_INLINE unsigned int nearestVert(SDefBindCalcData * const data, const float point_co[3])
+{
+	const MVert * const mvert = data->mvert;
+	BVHTreeNearest nearest = {.dist_sq = FLT_MAX, .index = -1};
+	const MPoly *poly;
+	const MEdge *edge;
+	const MLoop *loop;
+	float max_dist = FLT_MAX;
+	float dist;
+	unsigned int index = 0;
+
+	BLI_bvhtree_find_nearest(data->treeData->tree, point_co, &nearest, data->treeData->nearest_callback, data->treeData);
+
+	poly = &data->mpoly[data->looptri[nearest.index].poly];
+	loop = &data->mloop[poly->loopstart];
+
+	for (int i = 0; i < poly->totloop; i++, loop++) {
+		edge = &data->medge[loop->e];
+		dist = dist_squared_to_line_segment_v3(point_co, mvert[edge->v1].co, mvert[edge->v2].co);
+
+		if (dist < max_dist) {
+			max_dist = dist;
+			index = loop->e;
+		}
+	}
+
+	edge = &data->medge[index];
+	if (len_squared_v3v3(point_co, mvert[edge->v1].co) < len_squared_v3v3(point_co, mvert[edge->v2].co)) {
+		return edge->v1;
+	}
+	else {
+		return edge->v2;
+	}
+}
+
+BLI_INLINE int isPolyValid(const float coords[][2], const unsigned int nr)
+{
+	float prev_co[2];
+	float curr_vec[2], prev_vec[2];
+
+	if (!is_poly_convex_v2(coords, nr)) {
+		return MOD_SDEF_BIND_RESULT_CONCAVE_ERR;
+	}
+
+	copy_v2_v2(prev_co, coords[nr - 1]);
+	sub_v2_v2v2(prev_vec, prev_co, coords[nr - 2]);
+
+	for (int i = 0; i < nr; i++) {
+		sub_v2_v2v2(curr_vec, coords[i], prev_co);
+
+		if (len_squared_v2(curr_vec) < FLT_EPSILON) {
+			return MOD_SDEF_BIND_RESULT_OVERLAP_ERR;
+		}
+
+		if (1.0f - dot_v2v2(prev_vec, curr_vec) < FLT_EPSILON) {
+			return MOD_SDEF_BIND_RESULT_CONCAVE_ERR;
+		}
+
+		copy_v2_v2(prev_co, coords[i]);
+		copy_v2_v2(prev_vec, curr_vec);
+	}
+
+	return MOD_SDEF_BIND_RESULT_SUCCESS;
+}
+
+static void freeBindData(SDefBindWeightData * const bwdata)
+{
+	SDefBindPoly *bpoly = bwdata->bind_polys;
+
+	if (bwdata->bind_polys) {
+		for (int i = 0; i < bwdata->numpoly; bpoly++, i++) {
+			MEM_SAFE_FREE(bpoly->coords);
+			MEM_SAFE_FREE(bpoly->coords_v2);
+		}
+
+		MEM_freeN(bwdata->bind_polys);
+	}
+
+	MEM_freeN(bwdata);
+}
+
+BLI_INLINE float computeAngularWeight(const float point_angle, const float edgemid_angle)
+{
+	float weight;
+
+	weight = point_angle;
+	weight /= edgemid_angle;
+	weight *= M_PI_2;
+
+	return sinf(weight);
+}
+
+BLI_INLINE SDefBindWeightData *computeBindWeights(SDefBindCalcData * const data, const float point_co[3])
+{
+	const unsigned int nearest = nearestVert(data, point_co);
+	const SDefAdjacency * const vert_edges = data->vert_edges[nearest].first;
+	const SDefEdgePolys * const edge_polys = data->edge_polys;
+
+	const SDefAdjacency *vedge;
+	const MPoly *poly;
+	const MLoop *loop;
+
+	SDefBindWeightData *bwdata;
+	SDefBindPoly *bpoly;
+
+	float world[3] = {0.0f, 0.0f, 1.0f};
+	float avg_point_dist = 0.0f;
+	float tot_weight = 0.0f;
+	int inf_weight_flags = 0;
+
+	bwdata = MEM_callocN(sizeof(*bwdata), "SDefBindWeightData");
+	if (bwdata == NULL) {
+		data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+		return NULL;
+	}
+
+	bwdata->numpoly = data->vert_edges[nearest].num / 2;
+
+	bpoly = MEM_callocN(sizeof(*bpoly) * bwdata->numpoly, "SDefBindPoly");
+	if (bpoly == NULL) {
+		freeBindData(bwdata);
+		data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+		return NULL;
+	}
+
+	bwdata->bind_polys = bpoly;
+
+	/* Loop over all adjacent edges, and build the SDefBindPoly data for each poly adjacent to those */
+	for (vedge = vert_edges; vedge; vedge = vedge->next) {
+		unsigned int edge_ind = vedge->index;
+
+		for (int i = 0; i < edge_polys[edge_ind].num; i++) {
+			{
+				bpoly = bwdata->bind_polys;
+
+				for (int j = 0; j < bwdata->numpoly; bpoly++, j++) {
+					/* If coords isn't allocated, we have reached the first uninitialized bpoly */
+					if ((bpoly->index == edge_polys[edge_ind].polys[i]) || (!bpoly->coords)) {
+						break;
+					}
+				}
+			}
+
+			/* Check if poly was already created by another edge or still has to be initialized */
+			if (!bpoly->coords) {
+				float angle;
+				float axis[3];
+				float tmp_vec_v2[2];
+				int is_poly_valid;
+
+				bpoly->index = edge_polys[edge_ind].polys[i];
+				bpoly->coords = NULL;
+				bpoly->coords_v2 = NULL;
+
+				/* Copy poly data */
+				poly = &data->mpoly[bpoly->index];
+				loop = &data->mloop[poly->loopstart];
+
+				bpoly->numverts = poly->totloop;
+				bpoly->loopstart = poly->loopstart;
+
+				bpoly->coords = MEM_mallocN(sizeof(*bpoly->coords) * poly->totloop, "SDefBindPolyCoords");
+				if (bpoly->coords == NULL) {
+					freeBindData(bwdata);
+					data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+					return NULL;
+				}
+
+				bpoly->coords_v2 = MEM_mallocN(sizeof(*bpoly->coords_v2) * poly->totloop, "SDefBindPolyCoords_v2");
+				if (bpoly->coords_v2 == NULL) {
+					freeBindData(bwdata);
+					data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+					return NULL;
+				}
+
+				for (int j = 0; j < poly->totloop; j++, loop++) {
+					copy_v3_v3(bpoly->coords[j], data->mvert[loop->v].co);
+
+					/* Find corner and edge indices within poly loop array */
+					if (loop->v == nearest) {
+						bpoly->corner_ind = j;
+						bpoly->edge_vert_inds[0] = (j == 0) ? (poly->totloop - 1) : (j - 1);
+						bpoly->edge_vert_inds[1] = (j == poly->totloop - 1) ? (0) : (j + 1);
+
+						bpoly->edge_inds[0] = data->mloop[poly->loopstart + bpoly->edge_vert_inds[0]].e;
+						bpoly->edge_inds[1] = loop->e;
+					}
+				}
+
+				/* Compute poly's parametric data */
+				mid_v3_v3_array(bpoly->centroid, bpoly->coords, poly->totloop);
+				normal_poly_v3(bpoly->normal, bpoly->coords, poly->totloop);
+
+				/* Compute poly skew angle and axis */
+				angle = angle_normalized_v3v3(bpoly->normal, world);
+
+				cross_v3_v3v3(axis, bpoly->normal, world);
+				normalize_v3(axis);
+
+				/* Map coords onto 2d normal plane */
+				map_to_plane_axis_angle_v2_v3v3fl(bpoly->point_v2, point_co, axis, angle);
+
+				zero_v2(bpoly->centroid_v2);
+				for (int j = 0; j < poly->totloop; j++) {
+					map_to_plane_axis_angle_v2_v3v3fl(bpoly->coords_v2[j], bpoly->coords[j], axis, angle);
+					madd_v2_v2fl(bpoly->centroid_v2, bpoly->coords_v2[j], 1.0f / poly->totloop);
+				}
+
+				is_poly_valid = isPolyValid(bpoly->coords_v2, poly->totloop);
+
+				if (is_poly_valid != MOD_SDEF_BIND_RESULT_SUCCESS) {
+					freeBindData(bwdata);
+					data->success = is_poly_valid;
+					return NULL;
+				}
+
+				bpoly->inside = isect_point_poly_v2(bpoly->point_v2, bpoly->coords_v2, poly->totloop, false);
+
+				/* Initialize weight components */
+				bpoly->weight_angular = 1.0f;
+				bpoly->weight_dist_proj = len_v2v2(bpoly->centroid_v2, bpoly->point_v2);
+				bpoly->weight_dist = len_v3v3(bpoly->centroid, point_co);
+
+				avg_point_dist += bpoly->weight_dist;
+
+				/* Compute centroid to mid-edge vectors */
+				mid_v2_v2v2(bpoly->cent_edgemid_vecs_v2[0],
+				            bpoly->coords_v2[bpoly->edge_vert_inds[0]],
+				            bpoly->coords_v2[bpoly->corner_ind]);
+
+				mid_v2_v2v2(bpoly->cent_edgemid_vecs_v2[1],
+				            bpoly->coords_v2[bpoly->edge_vert_inds[1]],
+				            bpoly->coords_v2[bpoly->corner_ind]);
+
+				sub_v2_v2(bpoly->cent_edgemid_vecs_v2[0], bpoly->centroid_v2);
+				sub_v2_v2(bpoly->cent_edgemid_vecs_v2[1], bpoly->centroid_v2);
+
+				/* Compute poly scales with respect to mid-edges, and normalize the vectors */
+				bpoly->scales[0] = normalize_v2(bpoly->cent_edgemid_vecs_v2[0]);
+				bpoly->scales[1] = normalize_v2(bpoly->cent_edgemid_vecs_v2[1]);
+
+				/* Compute the required polygon angles */
+				bpoly->edgemid_angle = angle_normalized_v2v2(bpoly->cent_edgemid_vecs_v2[0], bpoly->cent_edgemid_vecs_v2[1]);
+
+				sub_v2_v2v2(tmp_vec_v2, bpoly->coords_v2[bpoly->corner_ind], bpoly->centroid_v2);
+				normalize_v2(tmp_vec_v2);
+
+				bpoly->corner_edgemid_angles[0] = angle_normalized_v2v2(tmp_vec_v2, bpoly->cent_edgemid_vecs_v2[0]);
+				bpoly->corner_edgemid_angles[1] = angle_normalized_v2v2(tmp_vec_v2, bpoly->cent_edgemid_vecs_v2[1]);
+
+				/* Check for inifnite weights, and compute angular data otherwise */
+				if (bpoly->weight_dist < FLT_EPSILON) {
+					inf_weight_flags |= MOD_SDEF_INFINITE_WEIGHT_DIST_PROJ;
+					inf_weight_flags |= MOD_SDEF_INFINITE_WEIGHT_DIST;
+				}
+				else if (bpoly->weight_dist_proj < FLT_EPSILON) {
+					inf_weight_flags |= MOD_SDEF_INFINITE_WEIGHT_DIST_PROJ;
+				}
+				else {
+					float cent_point_vec[2];
+
+					sub_v2_v2v2(cent_point_vec, bpoly->point_v2, bpoly->centroid_v2);
+					normalize_v2(cent_point_vec);
+
+					bpoly->point_edgemid_angles[0] = angle_normalized_v2v2(cent_point_vec, bpoly->cent_edgemid_vecs_v2[0]);
+					bpoly->point_edgemid_angles[1] = angle_normalized_v2v2(cent_point_vec, bpoly->cent_edgemid_vecs_v2[1]);
+				}
+			}
+		}
+	}
+
+	avg_point_dist /= bwdata->numpoly;
+
+	/* If weights 1 and 2 are not infinite, loop over all adjacent edges again,
+	 * and build adjacency dependent angle data (depends on all polygons having been computed) */
+	if (!inf_weight_flags) {
+		for (vedge = vert_edges; vedge; vedge = vedge->next) {
+			SDefBindPoly *bpolys[2];
+			const SDefEdgePolys *epolys;
+			float ang_weights[2];
+			unsigned int edge_ind = vedge->index;
+			unsigned int edge_on_poly[2];
+
+			epolys = &edge_polys[edge_ind];
+
+			/* Find bind polys corresponding to the edge's adjacent polys */
+			bpoly = bwdata->bind_polys;
+
+			for (int i = 0, j = 0; (i < bwdata->numpoly) && (j < epolys->num); bpoly++, i++) {
+				if (ELEM(bpoly->index, epolys->polys[0], epolys->polys[1])) {
+					bpolys[j] = bpoly;
+
+					if (bpoly->edge_inds[0] == edge_ind) {
+						edge_on_poly[j] = 0;
+					}
+					else {
+						edge_on_poly[j] = 1;
+					}
+
+					j++;
+				}
+			}
+
+			/* Compute angular weight component */
+			if (epolys->num == 1) {
+				ang_weights[0] = computeAngularWeight(bpolys[0]->point_edgemid_angles[edge_on_poly[0]], bpolys[0]->edgemid_angle);
+				bpolys[0]->weight_angular *= ang_weights[0] * ang_weights[0];
+			}
+			else if (epolys->num == 2) {
+				ang_weights[0] = computeAngularWeight(bpolys[0]->point_edgemid_angles[edge_on_poly[0]], bpolys[0]->edgemid_angle);
+				ang_weights[1] = computeAngularWeight(bpolys[1]->point_edgemid_angles[edge_on_poly[1]], bpolys[1]->edgemid_angle);
+
+				bpolys[0]->weight_angular *= ang_weights[0] * ang_weights[1];
+				bpolys[1]->weight_angular *= ang_weights[0] * ang_weights[1];
+			}
+		}
+	}
+
+	/* Compute scalings and falloff.
+	 * Scale all weights if no infinite weight is found,
+	 * scale only unprojected weight if projected weight is infinite,
+	 * scale none if both are infinite. */
+	if (!inf_weight_flags) {
+		bpoly = bwdata->bind_polys;
+
+		for (int i = 0; i < bwdata->numpoly; bpoly++, i++) {
+			float corner_angle_weights[2];
+			float scale_weight, sqr, inv_sqr;
+
+			corner_angle_weights[0] = bpoly->point_edgemid_angles[0] / bpoly->corner_edgemid_angles[0];
+			corner_angle_weights[1] = bpoly->point_edgemid_angles[1] / bpoly->corner_edgemid_angles[1];
+
+			if (isnan(corner_angle_weights[0]) || isnan(corner_angle_weights[1])) {
+				freeBindData(bwdata);
+				data->success = MOD_SDEF_BIND_RESULT_GENERIC_ERR;
+				return NULL;
+			}
+
+			/* Find which edge the point is closer to */
+			if (corner_angle_weights[0] < corner_angle_weights[1]) {
+				bpoly->dominant_edge = 0;
+				bpoly->dominant_angle_weight = corner_angle_weights[0];
+			}
+			else {
+				bpoly->dominant_edge = 1;
+				bpoly->dominant_angle_weight = corner_angle_weights[1];
+			}
+
+			bpoly->dominant_angle_weight = sinf(bpoly->dominant_angle_weight * M_PI_2);
+
+			/* Compute quadratic angular scale interpolation weight */
+			scale_weight = bpoly->point_edgemid_angles[bpoly->dominant_edge] / bpoly->edgemid_angle;
+			scale_weight /= scale_weight + (bpoly->point_edgemid_angles[!bpoly->dominant_edge] / bpoly->edgemid_angle);
+
+			sqr = scale_weight * scale_weight;
+			inv_sqr = 1.0f - scale_weight;
+			inv_sqr *= inv_sqr;
+			scale_weight = sqr / (sqr + inv_sqr);
+
+			/* Compute interpolated scale (no longer need the individual scales,
+			 * so simply storing the result over the scale in index zero) */
+			bpoly->scales[0] = bpoly->scales[bpoly->dominant_edge] * (1.0f - scale_weight) +
+			                   bpoly->scales[!bpoly->dominant_edge] * scale_weight;
+
+			/* Scale the point distance weights, and introduce falloff */
+			bpoly->weight_dist_proj /= bpoly->scales[0];
+			bpoly->weight_dist_proj = powf(bpoly->weight_dist_proj, data->falloff);
+
+			bpoly->weight_dist /= avg_point_dist;
+			bpoly->weight_dist = powf(bpoly->weight_dist, data->falloff);
+
+			/* Re-check for infinite weights, now that all scalings and interpolations are computed */
+			if (bpoly->weight_dist < FLT_EPSILON) {
+				inf_weight_flags |= MOD_SDEF_INFINITE_WEIGHT_DIST_PROJ;
+				inf_weight_flags |= MOD_SDEF_INFINITE_WEIGHT_DIST;
+			}
+			else if (bpoly->weight_dist_proj < FLT_EPSILON) {
+				inf_weight_flags |= MOD_SDEF_INFINITE_WEIGHT_DIST_PROJ;
+			}
+			else if (bpoly->weight_angular < FLT_EPSILON) {
+				inf_weight_flags |= MOD_SDEF_INFINITE_WEIGHT_ANGULAR;
+			}
+		}
+	}
+	else if (!(inf_weight_flags & MOD_SDEF_INFINITE_WEIGHT_DIST)) {
+		bpoly = bwdata->bind_polys;
+
+		for (int i = 0; i < bwdata->numpoly; bpoly++, i++) {
+			/* Scale the point distance weight by average point distance, and introduce falloff */
+			bpoly->weight_dist /= avg_point_dist;
+			bpoly->weight_dist = powf(bpoly->weight_dist, data->falloff);
+
+			/* Re-check for infinite weights, now that all scalings and interpolations are computed */
+			if (bpoly->weight_dist < FLT_EPSILON) {
+				inf_weight_flags |= MOD_SDEF_INFINITE_WEIGHT_DIST;
+			}
+		}
+	}
+
+	/* Final loop, to compute actual weights */
+	bpoly = bwdata->bind_polys;
+
+	for (int i = 0; i < bwdata->numpoly; bpoly++, i++) {
+		/* Weight computation from components */
+		if (inf_weight_flags & MOD_SDEF_INFINITE_WEIGHT_DIST) {
+			bpoly->weight = bpoly->weight_dist < FLT_EPSILON ? 1.0f : 0.0f;
+		}
+		else if (inf_weight_flags & MOD_SDEF_INFINITE_WEIGHT_DIST_PROJ) {
+			bpoly->weight = bpoly->weight_dist_proj < FLT_EPSILON ?
+			                1.0f / bpoly->weight_dist : 0.0f;
+		}
+		else if (inf_weight_flags & MOD_SDEF_INFINITE_WEIGHT_ANGULAR) {
+			bpoly->weight = bpoly->weight_angular < FLT_EPSILON ?
+			                1.0f / bpoly->weight_dist_proj / bpoly->weight_dist : 0.0f;
+		}
+		else {
+			bpoly->weight = 1.0f / bpoly->weight_angular /
+			                       bpoly->weight_dist_proj /
+			                       bpoly->weight_dist;
+		}
+
+		tot_weight += bpoly->weight;
+	}
+
+	bpoly = bwdata->bind_polys;
+
+	for (int i = 0; i < bwdata->numpoly; bpoly++, i++) {
+		bpoly->weight /= tot_weight;
+
+		/* Evaluate if this poly is relevant to bind */
+		/* Even though the weights should add up to 1.0,
+		 * the losses of weights smaller than epsilon here
+		 * should be negligible... */
+		if (bpoly->weight >= FLT_EPSILON) {
+			if (bpoly->inside) {
+				bwdata->numbinds += 1;
+			}
+			else {
+				if (bpoly->dominant_angle_weight < FLT_EPSILON || 1.0f - bpoly->dominant_angle_weight < FLT_EPSILON) {
+					bwdata->numbinds += 1;
+				}
+				else {
+					bwdata->numbinds += 2;
+				}
+			}
+		}
+	}
+
+	return bwdata;
+}
+
+BLI_INLINE float computeNormalDisplacement(const float point_co[3], const float point_co_proj[3], const float normal[3])
+{
+	float disp_vec[3];
+	float normal_dist;
+
+	sub_v3_v3v3(disp_vec, point_co, point_co_proj);
+	normal_dist = len_v3(disp_vec);
+
+	if (dot_v3v3(disp_vec, normal) < 0) {
+		normal_dist *= -1;
+	}
+
+	return normal_dist;
+}
+
+static void bindVert(void *userdata, void *UNUSED(userdata_chunk), const int index, const int UNUSED(threadid))
+{
+	SDefBindCalcData * const data = (SDefBindCalcData *)userdata;
+	float point_co[3];
+	float point_co_proj[3];
+
+	SDefBindWeightData *bwdata;
+	SDefVert *sdvert = data->bind_verts + index;
+	SDefBindPoly *bpoly;
+	SDefBind *sdbind;
+
+	if (data->success != MOD_SDEF_BIND_RESULT_SUCCESS) {
+		sdvert->binds = NULL;
+		sdvert->numbinds = 0;
+		return;
+	}
+
+	copy_v3_v3(point_co, data->vertexCos[index]);
+	bwdata = computeBindWeights(data, point_co);
+
+	if (bwdata == NULL) {
+		sdvert->binds = NULL;
+		sdvert->numbinds = 0;
+		return;
+	}
+
+	sdvert->binds = MEM_callocN(sizeof(*sdvert->binds) * bwdata->numbinds, "SDefVertBindData");
+	if (sdvert->binds == NULL) {
+		data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+		sdvert->numbinds = 0;
+		return;
+	}
+
+	sdvert->numbinds = bwdata->numbinds;
+
+	sdbind = sdvert->binds;
+
+	bpoly = bwdata->bind_polys;
+
+	for (int i = 0; i < bwdata->numbinds; bpoly++) {
+		if (bpoly->weight >= FLT_EPSILON) {
+			if (bpoly->inside) {
+				const MLoop *loop = &data->mloop[bpoly->loopstart];
+
+				sdbind->influence = bpoly->weight;
+				sdbind->numverts = bpoly->numverts;
+
+				sdbind->mode = MOD_SDEF_MODE_NGON;
+				sdbind->vert_weights = MEM_mallocN(sizeof(*sdbind->vert_weights) * bpoly->numverts, "SDefNgonVertWeights");
+				if (sdbind->vert_weights == NULL) {
+					data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+					return;
+				}
+
+				sdbind->vert_inds = MEM_mallocN(sizeof(*sdbind->vert_inds) * bpoly->numverts, "SDefNgonVertInds");
+				if (sdbind->vert_inds == NULL) {
+					data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+					return;
+				}
+
+				interp_weights_poly_v2(sdbind->vert_weights, bpoly->coords_v2, bpoly->numverts, bpoly->point_v2);
+
+				/* Reproject vert based on weights and original poly verts, to reintroduce poly non-planarity */
+				zero_v3(point_co_proj);
+				for (int j = 0; j < bpoly->numverts; j++, loop++) {
+					madd_v3_v3fl(point_co_proj, bpoly->coords[j], sdbind->vert_weights[j]);
+					sdbind->vert_inds[j] = loop->v;
+				}
+
+				sdbind->normal_dist = computeNormalDisplacement(point_co, point_co_proj, bpoly->normal);
+
+				sdbind++;
+				i++;
+			}
+			else {
+				float tmp_vec[3];
+				float cent[3], norm[3];
+				float v1[3], v2[3], v3[3];
+
+				if (1.0f - bpoly->dominant_angle_weight >= FLT_EPSILON) {
+					sdbind->influence = bpoly->weight * (1.0f - bpoly->dominant_angle_weight);
+					sdbind->numverts = bpoly->numverts;
+
+					sdbind->mode = MOD_SDEF_MODE_CENTROID;
+					sdbind->vert_weights = MEM_mallocN(sizeof(*sdbind->vert_weights) * 3, "SDefCentVertWeights");
+					if (sdbind->vert_weights == NULL) {
+						data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+						return;
+					}
+
+					sdbind->vert_inds = MEM_mallocN(sizeof(*sdbind->vert_inds) * bpoly->numverts, "SDefCentVertInds");
+					if (sdbind->vert_inds == NULL) {
+						data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+						return;
+					}
+
+					sortPolyVertsEdge(sdbind->vert_inds, &data->mloop[bpoly->loopstart],
+					                  bpoly->edge_inds[bpoly->dominant_edge], bpoly->numverts);
+
+					copy_v3_v3(v1, data->mvert[sdbind->vert_inds[0]].co);
+					copy_v3_v3(v2, data->mvert[sdbind->vert_inds[1]].co);
+					copy_v3_v3(v3, bpoly->centroid);
+
+					mid_v3_v3v3v3(cent, v1, v2, v3);
+					normal_tri_v3(norm, v1, v2, v3);
+
+					add_v3_v3v3(tmp_vec, point_co, bpoly->normal);
+
+					/* We are sure the line is not parallel to the plane.
+					 * Checking return value just to avoid warning... */
+					if (!isect_line_plane_v3(point_co_proj, point_co, tmp_vec, cent, norm)) {
+						BLI_assert(false);
+					}
+
+					interp_weights_tri_v3(sdbind->vert_weights, v1, v2, v3, point_co_proj);
+
+					sdbind->normal_dist = computeNormalDisplacement(point_co, point_co_proj, bpoly->normal);
+
+					sdbind++;
+					i++;
+				}
+
+				if (bpoly->dominant_angle_weight >= FLT_EPSILON) {
+					sdbind->influence = bpoly->weight * bpoly->dominant_angle_weight;
+					sdbind->numverts = bpoly->numverts;
+
+					sdbind->mode = MOD_SDEF_MODE_LOOPTRI;
+					sdbind->vert_weights = MEM_mallocN(sizeof(*sdbind->vert_weights) * 3, "SDefTriVertWeights");
+					if (sdbind->vert_weights == NULL) {
+						data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+						return;
+					}
+
+					sdbind->vert_inds = MEM_mallocN(sizeof(*sdbind->vert_inds) * bpoly->numverts, "SDefTriVertInds");
+					if (sdbind->vert_inds == NULL) {
+						data->success = MOD_SDEF_BIND_RESULT_MEM_ERR;
+						return;
+					}
+
+					sortPolyVertsTri(sdbind->vert_inds, &data->mloop[bpoly->loopstart], bpoly->edge_vert_inds[0], bpoly->numverts);
+
+					copy_v3_v3(v1, data->mvert[sdbind->vert_inds[0]].co);
+					copy_v3_v3(v2, data->mvert[sdbind->vert_inds[1]].co);
+					copy_v3_v3(v3, data->mvert[sdbind->vert_inds[2]].co);
+
+					mid_v3_v3v3v3(cent, v1, v2, v3);
+					normal_tri_v3(norm, v1, v2, v3);
+
+					add_v3_v3v3(tmp_vec, point_co, bpoly->normal);
+
+					/* We are sure the line is not parallel to the plane.
+					 * Checking return value just to avoid warning... */
+					if (!isect_line_plane_v3(point_co_proj, point_co, tmp_vec, cent, norm)) {
+						BLI_assert(false);
+					}
+
+					interp_weights_tri_v3(sdbind->vert_weights, v1, v2, v3, point_co_proj);
+
+					sdbind->normal_dist = computeNormalDisplacement(point_co, point_co_proj, bpoly->normal);
+
+					sdbind++;
+					i++;
+				}
+			}
+		}
+	}
+
+	freeBindData(bwdata);
+}
+
+static bool surfacedeformBind(SurfaceDeformModifierData *smd, float (*vertexCos)[3],
+                              unsigned int numverts, unsigned int tnumpoly, DerivedMesh *tdm)
+{
+	BVHTreeFromMesh treeData = {NULL};
+	const MPoly *mpoly = tdm->getPolyArray(tdm);
+	const MEdge *medge = tdm->getEdgeArray(tdm);
+	const MLoop *mloop = tdm->getLoopArray(tdm);
+	unsigned int tnumedges = tdm->getNumEdges(tdm);
+	unsigned int tnumverts = tdm->getNumVerts(tdm);
+	int adj_result;
+	SDefAdjacencyArray *vert_edges;
+	SDefAdjacency *adj_array;
+	SDefEdgePolys *edge_polys;
+
+	vert_edges = MEM_callocN(sizeof(*vert_edges) * tnumverts, "SDefVertEdgeMap");
+	if (vert_edges == NULL) {
+		modifier_setError((ModifierData *)smd, "Out of memory");
+		return false;
+	}
+
+	adj_array = MEM_mallocN(sizeof(*adj_array) * tnumedges * 2, "SDefVertEdge");
+	if (adj_array == NULL) {
+		modifier_setError((ModifierData *)smd, "Out of memory");
+		MEM_freeN(vert_edges);
+		return false;
+	}
+
+	edge_polys = MEM_callocN(sizeof(*edge_polys) * tnumedges, "SDefEdgeFaceMap");
+	if (edge_polys == NULL) {
+		modifier_setError((ModifierData *)smd, "Out of memory");
+		MEM_freeN(vert_edges);
+		MEM_freeN(adj_array);
+		return false;
+	}
+
+	smd->verts = MEM_mallocN(sizeof(*smd->verts) * numverts, "SDefBindVerts");
+	if (smd->verts == NULL) {
+		modifier_setError((ModifierData *)smd, "Out of memory");
+		freeAdjacencyMap(vert_edges, adj_array, edge_polys);
+		return false;
+	}
+
+	bvhtree_from_mesh_looptri(&treeData, tdm, 0.0, 2, 6);
+	if (treeData.tree == NULL) {
+		modifier_setError((ModifierData *)smd, "Out of memory");
+		freeAdjacencyMap(vert_edges, adj_array, edge_polys);
+		MEM_freeN(smd->verts);
+		smd->verts = NULL;
+		return false;
+	}
+
+	adj_result = buildAdjacencyMap(mpoly, medge, mloop, tnumpoly, tnumedges, vert_edges, adj_array, edge_polys);
+
+	if (adj_result == MOD_SDEF_BIND_RESULT_NONMANY_ERR) {
+		modifier_setError((ModifierData *)smd, "Target has edges with more than two polys");
+		freeAdjacencyMap(vert_edges, adj_array, edge_polys);
+		free_bvhtree_from_mesh(&treeData);
+		MEM_freeN(smd->verts);
+		smd->verts = NULL;
+		return false;
+	}
+
+	smd->numverts = numverts;
+	smd->numpoly = tnumpoly;
+
+	SDefBindCalcData data = {.treeData = &treeData,
+		                     .vert_edges = vert_edges,
+		                     .edge_polys = edge_polys,
+		                     .mpoly = mpoly,
+		                     .medge = medge,
+		                     .mloop = mloop,
+		                     .looptri = tdm->getLoopTriArray(tdm),
+		                     .mvert = tdm->getVertArray(tdm),
+		                     .bind_verts = smd->verts,
+		                     .vertexCos = vertexCos,
+		                     .falloff = smd->falloff,
+		                     .success = MOD_SDEF_BIND_RESULT_SUCCESS};
+
+	BLI_task_parallel_range_ex(0, numverts, &data, NULL, 0, bindVert,
+	                           numverts > 10000, false);
+
+	if (data.success == MOD_SDEF_BIND_RESULT_MEM_ERR) {
+		modifier_setError((ModifierData *)smd, "Out of memory");
+		freeData((ModifierData *)smd);
+	}
+	else if (data.success == MOD_SDEF_BIND_RESULT_NONMANY_ERR) {
+		modifier_setError((ModifierData *)smd, "Target has edges with more than two polys");
+		freeData((ModifierData *)smd);
+	}
+	else if (data.success == MOD_SDEF_BIND_RESULT_CONCAVE_ERR) {
+		modifier_setError((ModifierData *)smd, "Target contains concave polys");
+		freeData((ModifierData *)smd);
+	}
+	else if (data.success == MOD_SDEF_BIND_RESULT_OVERLAP_ERR) {
+		modifier_setError((ModifierData *)smd, "Target contains overlapping verts");
+		freeData((ModifierData *)smd);
+	}
+	else if (data.success == MOD_SDEF_BIND_RESULT_GENERIC_ERR) {
+		/* I know this message is vague, but I could not think of a way
+		 * to explain this whith a reasonably sized message.
+		 * Though it shouldn't really matter all that much,
+		 * because this is very unlikely to occur */
+		modifier_setError((ModifierData *)smd, "Target contains invalid polys");
+		freeData((ModifierData *)smd);
+	}
+
+	freeAdjacencyMap(vert_edges, adj_array, edge_polys);
+	free_bvhtree_from_mesh(&treeData);
+
+	return data.success == 1;
+}
+
+static void deformVert(void *userdata, void *UNUSED(userdata_chunk), const int index, const int UNUSED(threadid))
+{
+	const SDefDeformData * const data = (SDefDeformData *)userdata;
+	const SDefBind *sdbind = data->bind_verts[index].binds;
+	const MVert * const mvert = data->mvert;
+	float * const vertexCos = data->vertexCos[index];
+	float norm[3], temp[3];
+
+	zero_v3(vertexCos);
+
+	for (int j = 0; j < data->bind_verts[index].numbinds; j++, sdbind++) {
+		/* Mode-generic operations (allocate poly coordinates) */
+		float (*coords)[3] = MEM_mallocN(sizeof(*coords) * sdbind->numverts, "SDefDoPolyCoords");
+
+		for (int k = 0; k < sdbind->numverts; k++) {
+			copy_v3_v3(coords[k], mvert[sdbind->vert_inds[k]].co);
+		}
+
+		normal_poly_v3(norm, coords, sdbind->numverts);
+		zero_v3(temp);
+
+		/* ---------- looptri mode ---------- */
+		if (sdbind->mode == MOD_SDEF_MODE_LOOPTRI) {
+			madd_v3_v3fl(temp, mvert[sdbind->vert_inds[0]].co, sdbind->vert_weights[0]);
+			madd_v3_v3fl(temp, mvert[sdbind->vert_inds[1]].co, sdbind->vert_weights[1]);
+			madd_v3_v3fl(temp, mvert[sdbind->vert_inds[2]].co, sdbind->vert_weights[2]);
+		}
+		else {
+			/* ---------- ngon mode ---------- */
+			if (sdbind->mode == MOD_SDEF_MODE_NGON) {
+				for (int k = 0; k < sdbind->numverts; k++) {
+					madd_v3_v3fl(temp, coords[k], sdbind->vert_weights[k]);
+				}
+			}
+
+			/* ---------- centroid mode ---------- */
+			else if (sdbind->mode == MOD_SDEF_MODE_CENTROID) {
+				float cent[3];
+				mid_v3_v3_array(cent, coords, sdbind->numverts);
+
+				madd_v3_v3fl(temp, mvert[sdbind->vert_inds[0]].co, sdbind->vert_weights[0]);
+				madd_v3_v3fl(temp, mvert[sdbind->vert_inds[1]].co, sdbind->vert_weights[1]);
+				madd_v3_v3fl(temp, cent, sdbind->vert_weights[2]);
+			}
+		}
+
+		MEM_freeN(coords);
+
+		/* Apply normal offset (generic for all modes) */
+		madd_v3_v3fl(temp, norm, sdbind->normal_dist);
+
+		madd_v3_v3fl(vertexCos, temp, sdbind->influence);
+	}
+}
+
+static void surfacedeformModifier_do(ModifierData *md, float (*vertexCos)[3], unsigned int numverts)
+{
+	SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)md;
+	DerivedMesh *tdm;
+	unsigned int tnumpoly;
+
+	/* Exit function if bind flag is not set (free bind data if any) */
+	if (!(smd->flags & MOD_SDEF_BIND)) {
+		freeData(md);
+		return;
+	}
+
+	/* Handle target mesh both in and out of edit mode */
+	if (smd->target == md->scene->obedit) {
+		BMEditMesh *em = BKE_editmesh_from_object(smd->target);
+		tdm = em->derivedFinal;
+	}
+	else {
+		tdm = smd->target->derivedFinal;
+	}
+
+	tnumpoly = tdm->getNumPolys(tdm);
+
+	/* If not bound, execute bind */
+	if (!(smd->verts)) {
+		if (!surfacedeformBind(smd, vertexCos, numverts, tnumpoly, tdm)) {
+			smd->flags &= ~MOD_SDEF_BIND;
+			return;
+		}
+	}
+
+	/* Poly count checks */
+	if (smd->numverts != numverts) {
+		modifier_setError(md, "Verts changed from %u to %u", smd->numverts, numverts);
+		tdm->release(tdm);
+		return;
+	}
+	else if (smd->numpoly != tnumpoly) {
+		modifier_setError(md, "Target polygons changed from %u to %u", smd->numpoly, tnumpoly);
+		tdm->release(tdm);
+		return;
+	}
+
+	/* Actual vertex location update starts here */
+	SDefDeformData data = {.bind_verts = smd->verts,
+		                   .mvert = tdm->getVertArray(tdm),
+		                   .vertexCos = vertexCos};
+
+	BLI_task_parallel_range_ex(0, numverts, &data, NULL, 0, deformVert,
+	                           numverts > 10000, false);
+
+	tdm->release(tdm);
+}
+
+static void deformVerts(ModifierData *md, Object *UNUSED(ob),
+                        DerivedMesh *UNUSED(derivedData),
+                        float (*vertexCos)[3], int numVerts,
+                        ModifierApplyFlag UNUSED(flag))
+{
+	surfacedeformModifier_do(md, vertexCos, numVerts);
+}
+
+static void deformVertsEM(ModifierData *md, Object *UNUSED(ob),
+                          struct BMEditMesh *UNUSED(editData),
+                          DerivedMesh *UNUSED(derivedData),
+                          float (*vertexCos)[3], int numVerts)
+{
+	surfacedeformModifier_do(md, vertexCos, numVerts);
+}
+
+static bool isDisabled(ModifierData *md, int UNUSED(useRenderParams))
+{
+	SurfaceDeformModifierData *smd = (SurfaceDeformModifierData *)md;
+
+	return !smd->target;
+}
+
+ModifierTypeInfo modifierType_SurfaceDeform = {
+	/* name */              "Surface Deform",
+	/* structName */        "SurfaceDeformModifierData",
+	/* structSize */        sizeof(SurfaceDeformModifierData),
+	/* type */              eModifierTypeType_OnlyDeform,
+	/* flags */             eModifierTypeFlag_AcceptsMesh |
+	                        eModifierTypeFlag_SupportsEditmode,
+
+	/* copyData */          copyData,
+	/* deformVerts */       deformVerts,
+	/* deformMatrices */    NULL,
+	/* deformVertsEM */     deformVertsEM,
+	/* deformMatricesEM */  NULL,
+	/* applyModifier */     NULL,
+	/* applyModifierEM */   NULL,
+	/* initData */          initData,
+	/* requiredDataMask */  NULL,
+	/* freeData */          freeData,
+	/* isDisabled */        isDisabled,
+	/* updateDepgraph */    updateDepgraph,
+	/* updateDepsgraph */   updateDepsgraph,
+	/* dependsOnTime */     NULL,
+	/* dependsOnNormals */  NULL,
+	/* foreachObjectLink */ foreachObjectLink,
+	/* foreachIDLink */     NULL,
+	/* foreachTexLink */    NULL,
+};
diff --git a/source/blender/modifiers/intern/MOD_util.c b/source/blender/modifiers/intern/MOD_util.c
index 93414562ccf..ded1f0b77e6 100644
--- a/source/blender/modifiers/intern/MOD_util.c
+++ b/source/blender/modifiers/intern/MOD_util.c
@@ -287,5 +287,6 @@ void modifier_type_init(ModifierTypeInfo *types[])
 	INIT_TYPE(NormalEdit);
 	INIT_TYPE(CorrectiveSmooth);
 	INIT_TYPE(MeshSequenceCache);
+	INIT_TYPE(SurfaceDeform);
 #undef INIT_TYPE
 }