new mesh tool for cleaning up meshes, splits up non-planar faces while they exceed a given angle threshold

(access from the 'Mesh -> Clean' menu).

7 files changed, 299 insertions, 0 deletions

diff --git a/source/blender/bmesh/CMakeLists.txt b/source/blender/bmesh/CMakeLists.txt
index c49c290e81e..228ebcb96c4 100644
--- a/source/blender/bmesh/CMakeLists.txt
+++ b/source/blender/bmesh/CMakeLists.txt
@@ -43,6 +43,7 @@ set(SRC
 	operators/bmo_bevel.c
 	operators/bmo_bridge.c
 	operators/bmo_connect.c
+	operators/bmo_connect_nonplanar.c
 	operators/bmo_connect_pair.c
 	operators/bmo_create.c
 	operators/bmo_dissolve.c
diff --git a/source/blender/bmesh/intern/bmesh_opdefines.c b/source/blender/bmesh/intern/bmesh_opdefines.c
index b56ed15b901..4f8a851c780 100644
--- a/source/blender/bmesh/intern/bmesh_opdefines.c
+++ b/source/blender/bmesh/intern/bmesh_opdefines.c
@@ -868,6 +868,27 @@ static BMOpDefine bmo_connect_verts_def = {
 };
 
 /*
+ * Connect Verts Across non Planer Faces.
+ *
+ * Split faces by connecting edges along non planer **faces**.
+ */
+static BMOpDefine bmo_connect_verts_nonplanar_def = {
+	"connect_verts_nonplanar",
+	/* slots_in */
+	{{"angle_limit", BMO_OP_SLOT_FLT}, /* total rotation angle (radians) */
+	 {"faces", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
+	 {{'\0'}},
+	},
+	/* slots_out */
+	{{"edges.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_EDGE}},
+	 {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
+	 {{'\0'}},
+	},
+	bmo_connect_verts_nonplanar_exec,
+	BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH,
+};
+
+/*
  * Connect Verts.
  *
  * Split faces by adding edges that connect **verts**.
@@ -1734,6 +1755,7 @@ const BMOpDefine *bmo_opdefines[] = {
 	&bmo_collapse_def,
 	&bmo_collapse_uvs_def,
 	&bmo_connect_verts_def,
+	&bmo_connect_verts_nonplanar_def,
 	&bmo_connect_vert_pair_def,
 	&bmo_contextual_create_def,
 #ifdef WITH_BULLET
diff --git a/source/blender/bmesh/intern/bmesh_operators_private.h b/source/blender/bmesh/intern/bmesh_operators_private.h
index e029ad0d124..33c10411c0f 100644
--- a/source/blender/bmesh/intern/bmesh_operators_private.h
+++ b/source/blender/bmesh/intern/bmesh_operators_private.h
@@ -40,6 +40,7 @@ void bmo_bridge_loops_exec(BMesh *bm, BMOperator *op);
 void bmo_collapse_exec(BMesh *bm, BMOperator *op);
 void bmo_collapse_uvs_exec(BMesh *bm, BMOperator *op);
 void bmo_connect_verts_exec(BMesh *bm, BMOperator *op);
+void bmo_connect_verts_nonplanar_exec(BMesh *bm, BMOperator *op);
 void bmo_connect_vert_pair_exec(BMesh *bm, BMOperator *op);
 void bmo_contextual_create_exec(BMesh *bm, BMOperator *op);
 void bmo_convex_hull_exec(BMesh *bm, BMOperator *op);
diff --git a/source/blender/bmesh/operators/bmo_connect_nonplanar.c b/source/blender/bmesh/operators/bmo_connect_nonplanar.c
new file mode 100644
index 00000000000..74f42e73aab
--- /dev/null
+++ b/source/blender/bmesh/operators/bmo_connect_nonplanar.c
@@ -0,0 +1,228 @@
+/*
+ * ***** 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.
+ *
+ * Contributor(s): Campbell Barton
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/bmesh/operators/bmo_connect_nonplanar.c
+ *  \ingroup bmesh
+ *
+ * Connect verts non-planer faces iteratively (splits faces).
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_math.h"
+#include "BLI_utildefines.h"
+#include "BLI_alloca.h"
+
+#include "bmesh.h"
+
+#include "intern/bmesh_operators_private.h" /* own include */
+
+#define EDGE_OUT	(1 << 0)
+#define FACE_OUT	(1 << 1)
+
+/**
+ * Calculates the face subset normal.
+ */
+static bool bm_face_subset_calc_normal(BMLoop *l_first, BMLoop *l_last, float r_no[3])
+{
+	float const *v_prev, *v_curr;
+
+	/* Newell's Method */
+	BMLoop *l_iter = l_first;
+	BMLoop *l_term = l_last->next;
+
+	zero_v3(r_no);
+
+	v_prev = l_last->v->co;
+	do {
+		v_curr = l_iter->v->co;
+		add_newell_cross_v3_v3v3(r_no, v_prev, v_curr);
+		v_prev = v_curr;
+	} while ((l_iter = l_iter->next) != l_term);
+
+	return (normalize_v3(r_no) != 0.0f);
+}
+
+/**
+ * Calculates how non-planar the face subset is.
+ */
+static float bm_face_subset_calc_planar(BMLoop *l_first, BMLoop *l_last, const float no[3])
+{
+	float axis_mat[3][3];
+	float z_prev, z_curr;
+	float delta_z = 0.0f;
+
+	/* Newell's Method */
+	BMLoop *l_iter = l_first;
+	BMLoop *l_term = l_last->next;
+
+	axis_dominant_v3_to_m3(axis_mat, no);
+
+	z_prev = mul_m3_v3_single_z(axis_mat, l_last->v->co);
+	do {
+		z_curr = mul_m3_v3_single_z(axis_mat, l_iter->v->co);
+		delta_z += fabsf(z_curr - z_prev);
+		z_prev = z_curr;
+	} while ((l_iter = l_iter->next) != l_term);
+
+	return delta_z;
+}
+
+static bool bm_face_split_find(BMFace *f, BMVert *v_pair[2], float *r_angle)
+{
+	BMLoop *l_iter, *l_first;
+	BMLoop **l_arr = BLI_array_alloca(l_arr, f->len);
+	const unsigned int f_len = f->len;
+	unsigned int i_a, i_b;
+	bool found = false;
+
+	/* angle finding */
+	float err_best = FLT_MAX;
+	float angle_best = FLT_MAX;
+
+	l_iter = l_first = BM_FACE_FIRST_LOOP(f);
+	i_a = 0;
+	do {
+		l_arr[i_a++] = l_iter;
+	} while ((l_iter = l_iter->next) != l_first);
+
+	/* now for the big search, O(N^2), however faces normally aren't so large */
+	for (i_a = 0; i_a < f_len; i_a++) {
+		BMLoop *l_a = l_arr[i_a];
+		for (i_b = i_a + 2; i_b < f_len; i_b++) {
+			BMLoop *l_b = l_arr[i_b];
+			/* check these are not touching
+			 * (we could be smarter here) */
+			if ((l_a->next != l_b) &&
+			    (l_a->prev != l_b))
+			{
+				/* first calculate normals */
+				float no_a[3], no_b[3];
+
+				if (bm_face_subset_calc_normal(l_a, l_b, no_a) &&
+				    bm_face_subset_calc_normal(l_b, l_a, no_b))
+				{
+					const float err_a = bm_face_subset_calc_planar(l_a, l_b, no_a);
+					const float err_b = bm_face_subset_calc_planar(l_b, l_a, no_b);
+					const float err_test = err_a + err_b;
+
+					if (err_test < err_best) {
+						/* check we're legal (we could batch this) */
+						BMLoop *l_split[2] = {l_a, l_b};
+						BM_face_legal_splits(f, &l_split, 1);
+						if (l_split[0]) {
+							err_best = err_test;
+							v_pair[0] = l_a->v;
+							v_pair[1] = l_b->v;
+
+							angle_best = angle_normalized_v3v3(no_a, no_b);
+							found = true;
+						}
+					}
+				}
+			}
+		}
+	}
+
+	*r_angle = angle_best;
+
+	return found;
+
+
+}
+
+static bool bm_face_split_by_angle(BMesh *bm, BMFace *f, BMFace *r_f_pair[2], const float angle_limit)
+{
+	BMVert *v_pair[2];
+	float angle;
+
+	if (bm_face_split_find(f, v_pair, &angle) && (angle > angle_limit)) {
+		BMFace *f_new;
+		BMLoop *l_new;
+		f_new = BM_face_split(bm, f, v_pair[0], v_pair[1], &l_new, NULL, false);
+		if (f_new) {
+			r_f_pair[0] = f;
+			r_f_pair[1] = f_new;
+
+			BMO_elem_flag_enable(bm, f, FACE_OUT);
+			BMO_elem_flag_enable(bm, f_new, FACE_OUT);
+			BMO_elem_flag_enable(bm, l_new->e, EDGE_OUT);
+			return true;
+		}
+	}
+
+	return false;
+
+}
+
+void bmo_connect_verts_nonplanar_exec(BMesh *bm, BMOperator *op)
+{
+	BMOIter siter;
+	BMFace *f;
+	int totface = 0, totloop = 0;
+	int tottris;
+	BMFace **fstack;
+	STACK_DECLARE(fstack);
+
+	const float angle_limit = BMO_slot_float_get(op->slots_in, "angle_limit");
+
+
+	BMO_ITER (f, &siter, op->slots_in, "faces", BM_FACE) {
+		if (f->len > 3) {
+			totface += 1;
+			totloop += f->len;
+		}
+	}
+
+	if (totface == 0) {
+		return;
+	}
+
+	/* over alloc, if we split every face */
+	tottris = poly_to_tri_count(totface, totloop);
+	fstack = MEM_mallocN(sizeof(BMFace *) * tottris, __func__);
+
+	STACK_INIT(fstack);
+
+	BMO_ITER (f, &siter, op->slots_in, "faces", BM_FACE) {
+		if (f->len > 3) {
+			STACK_PUSH(fstack, f);
+		}
+	}
+
+	while ((f = STACK_POP(fstack))) {
+		BMFace *f_pair[2];
+		if (bm_face_split_by_angle(bm, f, f_pair, angle_limit)) {
+			int j;
+			for (j = 0; j < 2; j++) {
+				if (f_pair[j]->len > 3) {
+					STACK_PUSH(fstack, f_pair[j]);
+				}
+			}
+		}
+	}
+
+	MEM_freeN(fstack);
+
+	BMO_slot_buffer_from_enabled_flag(bm, op, op->slots_out, "edges.out", BM_EDGE, EDGE_OUT);
+	BMO_slot_buffer_from_enabled_flag(bm, op, op->slots_out, "faces.out", BM_FACE, FACE_OUT);
+}
diff --git a/source/blender/editors/mesh/editmesh_tools.c b/source/blender/editors/mesh/editmesh_tools.c
index dd96778caad..868db4fa746 100644
--- a/source/blender/editors/mesh/editmesh_tools.c
+++ b/source/blender/editors/mesh/editmesh_tools.c
@@ -802,6 +802,51 @@ void MESH_OT_vert_connect(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 }
 
+
+static int edbm_vert_connect_nonplaner_exec(bContext *C, wmOperator *op)
+{
+	Object *obedit = CTX_data_edit_object(C);
+	BMEditMesh *em = BKE_editmesh_from_object(obedit);
+
+	const float angle_limit = RNA_float_get(op->ptr, "angle_limit");
+
+	if (!EDBM_op_call_and_selectf(
+	             em, op,
+	             "faces.out", true,
+	             "connect_verts_nonplanar faces=%hf angle_limit=%f",
+	             BM_ELEM_SELECT, angle_limit))
+	{
+		return OPERATOR_CANCELLED;
+	}
+
+
+	EDBM_update_generic(em, true, true);
+	return OPERATOR_FINISHED;
+}
+
+void MESH_OT_vert_connect_nonplanar(wmOperatorType *ot)
+{
+	PropertyRNA *prop;
+
+	/* identifiers */
+	ot->name = "Split Non-Planar Faces";
+	ot->idname = "MESH_OT_vert_connect_nonplanar";
+	ot->description = "Split non-planar faces that exceed the angle threshold";
+
+	/* api callbacks */
+	ot->exec = edbm_vert_connect_nonplaner_exec;
+	ot->poll = ED_operator_editmesh;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+	/* props */
+	prop = RNA_def_float_rotation(ot->srna, "angle_limit", 0, NULL, 0.0f, DEG2RADF(180.0f),
+	                              "Max Angle", "Angle limit", 0.0f, DEG2RADF(180.0f));
+	RNA_def_property_float_default(prop, DEG2RADF(5.0f));
+}
+
+
 static int edbm_edge_split_exec(bContext *C, wmOperator *op)
 {
 	Object *obedit = CTX_data_edit_object(C);
diff --git a/source/blender/editors/mesh/mesh_intern.h b/source/blender/editors/mesh/mesh_intern.h
index c76b9819f75..b2d6e872206 100644
--- a/source/blender/editors/mesh/mesh_intern.h
+++ b/source/blender/editors/mesh/mesh_intern.h
@@ -166,6 +166,7 @@ void MESH_OT_normals_make_consistent(struct wmOperatorType *ot);
 void MESH_OT_vertices_smooth(struct wmOperatorType *ot);
 void MESH_OT_vertices_smooth_laplacian(struct wmOperatorType *ot);
 void MESH_OT_vert_connect(struct wmOperatorType *ot);
+void MESH_OT_vert_connect_nonplanar(struct wmOperatorType *ot);
 void MESH_OT_edge_split(struct wmOperatorType *ot);
 void MESH_OT_bridge_edge_loops(struct wmOperatorType *ot);
 void MESH_OT_wireframe(struct wmOperatorType *ot);
diff --git a/source/blender/editors/mesh/mesh_ops.c b/source/blender/editors/mesh/mesh_ops.c
index 74aaa58d32d..90dc803ea50 100644
--- a/source/blender/editors/mesh/mesh_ops.c
+++ b/source/blender/editors/mesh/mesh_ops.c
@@ -156,6 +156,7 @@ void ED_operatortypes_mesh(void)
 	WM_operatortype_append(MESH_OT_solidify);
 	WM_operatortype_append(MESH_OT_select_nth);
 	WM_operatortype_append(MESH_OT_vert_connect);
+	WM_operatortype_append(MESH_OT_vert_connect_nonplanar);
 	WM_operatortype_append(MESH_OT_knife_tool);
 	WM_operatortype_append(MESH_OT_knife_project);