4 files changed, 93 insertions, 0 deletions

diff --git a/source/blender/editors/object/object_intern.h b/source/blender/editors/object/object_intern.h
index ef8653541f0..2cc8671d84b 100644
--- a/source/blender/editors/object/object_intern.h
+++ b/source/blender/editors/object/object_intern.h
@@ -175,6 +175,7 @@ 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);
+void OBJECT_OT_hair_generate_follicles(struct wmOperatorType *ot);
 
 /* grease pencil modifiers */
 void OBJECT_OT_gpencil_modifier_add(struct wmOperatorType *ot);
diff --git a/source/blender/editors/object/object_modifier.c b/source/blender/editors/object/object_modifier.c
index 43f651b0532..8384755c679 100644
--- a/source/blender/editors/object/object_modifier.c
+++ b/source/blender/editors/object/object_modifier.c
@@ -37,6 +37,7 @@
 #include "DNA_anim_types.h"
 #include "DNA_armature_types.h"
 #include "DNA_curve_types.h"
+#include "DNA_hair_types.h"
 #include "DNA_key_types.h"
 #include "DNA_mesh_types.h"
 #include "DNA_meshdata_types.h"
@@ -58,12 +59,14 @@
 #include "BKE_DerivedMesh.h"
 #include "BKE_effect.h"
 #include "BKE_global.h"
+#include "BKE_hair.h"
 #include "BKE_key.h"
 #include "BKE_lattice.h"
 #include "BKE_main.h"
 #include "BKE_mesh.h"
 #include "BKE_mesh_mapping.h"
 #include "BKE_mesh_runtime.h"
+#include "BKE_mesh_sample.h"
 #include "BKE_modifier.h"
 #include "BKE_multires.h"
 #include "BKE_report.h"
@@ -2417,3 +2420,88 @@ void OBJECT_OT_surfacedeform_bind(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
 	edit_modifier_properties(ot);
 }
+
+/************************ Hair follicle generate operator *********************/
+
+static int hair_generate_follicles_poll(bContext *C)
+{
+	return edit_modifier_poll_generic(C, &RNA_HairModifier, 0);
+}
+
+static int hair_generate_follicles_exec(bContext *C, wmOperator *op)
+{
+	Object *ob = ED_object_active_context(C);
+	HairModifierData *hmd = (HairModifierData *)edit_modifier_property_get(op, ob, eModifierType_Hair);
+
+	if (!hmd)
+		return OPERATOR_CANCELLED;
+
+	BLI_assert(hmd->hair_system != NULL);
+	
+	struct Depsgraph *depsgraph = CTX_data_depsgraph(C);
+	
+	BLI_assert(ob && ob->type == OB_MESH);
+	Mesh *scalp = (Mesh *)DEG_get_evaluated_id(depsgraph, ob->data);
+	HairSystem *hsys = hmd->hair_system;
+	
+	BKE_hair_generate_follicles(
+	            hsys,
+	            scalp,
+	            (unsigned int)hmd->follicle_seed,
+	            hmd->follicle_count);
+	
+	{
+		const int numverts = 5;
+		const float hairlen = 0.05f;
+		const float taper_length = 0.02f;
+		const float taper_thickness = 0.8f;
+		BKE_hair_fiber_curves_begin(hsys, hsys->pattern->num_follicles);
+		for (int i = 0; i < hsys->pattern->num_follicles; ++i)
+		{
+			BKE_hair_set_fiber_curve(hsys, i, numverts, taper_length, taper_thickness);
+		}
+		BKE_hair_fiber_curves_end(hsys);
+		for (int i = 0; i < hsys->pattern->num_follicles; ++i)
+		{
+			float loc[3], nor[3], tan[3];
+			BKE_mesh_sample_eval(scalp, &hsys->pattern->follicles[i].mesh_sample, loc, nor, tan);
+			for (int j = 0; j < numverts; ++j)
+			{
+				madd_v3_v3fl(loc, nor, hairlen / (numverts-1));
+				BKE_hair_set_fiber_vertex(hsys, i * numverts + j, 0, loc);
+			}
+		}
+	}
+	
+	BKE_hair_bind_follicles(hmd->hair_system, scalp);
+	
+	DEG_id_tag_update(&ob->id, OB_RECALC_DATA);
+	WM_event_add_notifier(C, NC_OBJECT | ND_MODIFIER, ob);
+	
+	return OPERATOR_FINISHED;
+}
+
+static int hair_generate_follicles_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
+{
+	if (edit_modifier_invoke_properties(C, op))
+		return hair_generate_follicles_exec(C, op);
+	else
+		return OPERATOR_CANCELLED;
+}
+
+void OBJECT_OT_hair_generate_follicles(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Hair Follicles Generate";
+	ot->description = "Generate hair follicles for a hair modifier";
+	ot->idname = "OBJECT_OT_hair_generate_follicles";
+
+	/* api callbacks */
+	ot->poll = hair_generate_follicles_poll;
+	ot->invoke = hair_generate_follicles_invoke;
+	ot->exec = hair_generate_follicles_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 ac2eb60456f..16ea0791adf 100644
--- a/source/blender/editors/object/object_ops.c
+++ b/source/blender/editors/object/object_ops.c
@@ -263,6 +263,7 @@ 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);
+	WM_operatortype_append(OBJECT_OT_hair_generate_follicles);
 
 	WM_operatortype_append(OBJECT_OT_hide_view_clear);
 	WM_operatortype_append(OBJECT_OT_hide_view_set);
diff --git a/source/blender/editors/space_outliner/outliner_draw.c b/source/blender/editors/space_outliner/outliner_draw.c
index 211c9e1a392..5244c364b80 100644
--- a/source/blender/editors/space_outliner/outliner_draw.c
+++ b/source/blender/editors/space_outliner/outliner_draw.c
@@ -1039,6 +1039,9 @@ TreeElementIcon tree_element_get_icon(TreeStoreElem *tselem, TreeElement *te)
 						case eModifierType_WeightedNormal:
 							data.icon = ICON_MOD_NORMALEDIT;
 							break;
+						case eModifierType_Hair:
+							data.icon = ICON_STRANDS;
+							break;
 							/* Default */
 						case eModifierType_None:
 						case eModifierType_ShapeKey: