Fix edge/vert slide UV-correct & zero length edges

When calculating loop angle weighting, skip overlapping vertices.

3 files changed, 54 insertions, 1 deletions

diff --git a/source/blender/bmesh/intern/bmesh_queries.c b/source/blender/bmesh/intern/bmesh_queries.c
index 182bd17c486..09284ea3549 100644
--- a/source/blender/bmesh/intern/bmesh_queries.c
+++ b/source/blender/bmesh/intern/bmesh_queries.c
@@ -1379,6 +1379,46 @@ void BM_edge_ordered_verts(const BMEdge *edge, BMVert **r_v1, BMVert **r_v2)
 }
 
 /**
+ * \return The previous loop, over \a eps_sq distance from \a l (or \a NULL if l_stop is reached).
+ */
+BMLoop *BM_loop_find_prev_nodouble(BMLoop *l, BMLoop *l_stop, const float eps_sq)
+{
+	BMLoop *l_step = l->prev;
+
+	BLI_assert(!ELEM(l_stop, NULL, l));
+
+	while (UNLIKELY(len_squared_v3v3(l->v->co, l_step->v->co) < eps_sq)) {
+		l_step = l_step->prev;
+		BLI_assert(l_step != l);
+		if (UNLIKELY(l_step == l_stop)) {
+			return NULL;
+		}
+	}
+
+	return l_step;
+}
+
+/**
+ * \return The next loop, over \a eps_sq distance from \a l (or \a NULL if l_stop is reached).
+ */
+BMLoop *BM_loop_find_next_nodouble(BMLoop *l, BMLoop *l_stop, const float eps_sq)
+{
+	BMLoop *l_step = l->next;
+
+	BLI_assert(!ELEM(l_stop, NULL, l));
+
+	while (UNLIKELY(len_squared_v3v3(l->v->co, l_step->v->co) < eps_sq)) {
+		l_step = l_step->next;
+		BLI_assert(l_step != l);
+		if (UNLIKELY(l_step == l_stop)) {
+			return NULL;
+		}
+	}
+
+	return l_step;
+}
+
+/**
  * Check if the loop is convex or concave
  * (depends on face normal)
  */
diff --git a/source/blender/bmesh/intern/bmesh_queries.h b/source/blender/bmesh/intern/bmesh_queries.h
index f96d99fd452..2b18a5c8641 100644
--- a/source/blender/bmesh/intern/bmesh_queries.h
+++ b/source/blender/bmesh/intern/bmesh_queries.h
@@ -108,6 +108,9 @@ BLI_INLINE bool BM_loop_is_adjacent(const BMLoop *l_a, const BMLoop *l_b) ATTR_W
 float   BM_loop_point_side_of_loop_test(const BMLoop *l, const float co[3]) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 float   BM_loop_point_side_of_edge_test(const BMLoop *l, const float co[3]) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 
+BMLoop *BM_loop_find_prev_nodouble(BMLoop *l, BMLoop *l_stop, const float eps_sq);
+BMLoop *BM_loop_find_next_nodouble(BMLoop *l, BMLoop *l_stop, const float eps_sq);
+
 float   BM_loop_calc_face_angle(const BMLoop *l) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 void    BM_loop_calc_face_normal(const BMLoop *l, float r_normal[3]) ATTR_NONNULL();
 void    BM_loop_calc_face_direction(const BMLoop *l, float r_normal[3]);
diff --git a/source/blender/editors/transform/transform.c b/source/blender/editors/transform/transform.c
index 3a8e7cfa91a..bf09fd3d00e 100644
--- a/source/blender/editors/transform/transform.c
+++ b/source/blender/editors/transform/transform.c
@@ -5324,12 +5324,22 @@ static void slide_origdata_create_data_vert(
 	loop_weights = BLI_array_alloca(loop_weights, l_num);
 	for (j = 0; j < l_num; j++) {
 		BMLoop *l = BM_iter_step(&liter);
+		BMLoop *l_prev, *l_next;
 		void **val_p;
 		if (!BLI_ghash_ensure_p(sod->origfaces, l->f, &val_p)) {
 			BMFace *f_copy = BM_face_copy(sod->bm_origfaces, bm, l->f, true, true);
 			*val_p = f_copy;
 		}
-		loop_weights[j] = BM_loop_calc_face_angle(l);
+
+		if ((l_prev = BM_loop_find_prev_nodouble(l, l->next, FLT_EPSILON)) &&
+		    (l_next = BM_loop_find_next_nodouble(l, l_prev,  FLT_EPSILON)))
+		{
+			loop_weights[j] = angle_v3v3v3(l_prev->v->co, l->v->co, l_next->v->co);
+		}
+		else {
+			loop_weights[j] = 0.0f;
+		}
+
 	}
 
 	/* store cd_loop_groups */