Fix edge/vert slide UV-correct & non-planar faces

non-flat ngons would give instability (bad UV's).

1 files changed, 20 insertions, 5 deletions

diff --git a/source/blender/editors/transform/transform.c b/source/blender/editors/transform/transform.c
index bf09fd3d00e..1e3622b8750 100644
--- a/source/blender/editors/transform/transform.c
+++ b/source/blender/editors/transform/transform.c
@@ -5407,6 +5407,13 @@ static void slide_origdata_interp_data_vert(
 	int j, l_num;
 	float *loop_weights;
 	const bool do_loop_weight = (len_squared_v3v3(sv->v->co, sv->co_orig_3d) > FLT_EPSILON);
+	const float *v_proj_axis = sv->v->no;
+	/* original (l->prev, l, l->next) projections for each loop ('l' remains unchanged) */
+	float v_proj[3][3];
+
+	if (do_loop_weight) {
+		project_plane_v3_v3v3(v_proj[1], sv->co_orig_3d, v_proj_axis);
+	}
 
 	// BM_ITER_ELEM (l, &liter, sv->v, BM_LOOPS_OF_VERT) {
 	BM_iter_init(&liter, bm, BM_LOOPS_OF_VERT, sv->v);
@@ -5435,24 +5442,32 @@ static void slide_origdata_interp_data_vert(
 			bool co_prev_ok;
 			bool co_next_ok;
 
+
 			/* In the unlikely case that we're next to a zero length edge - walk around the to the next.
 			 * Since we only need to check if the vertex is in this corner,
 			 * its not important _which_ loop - as long as its not overlapping 'sv->co_orig_3d', see: T45096. */
-			while (UNLIKELY(((co_prev_ok = (len_squared_v3v3(sv->co_orig_3d, co_prev) > eps)) == false) &&
+			project_plane_v3_v3v3(v_proj[0], co_prev, v_proj_axis);
+			while (UNLIKELY(((co_prev_ok = (len_squared_v3v3(v_proj[1], v_proj[0]) > eps)) == false) &&
 			                ((l_prev = l_prev->prev) != l->next)))
 			{
 				co_prev = slide_origdata_orig_vert_co(sod, l_prev->v);
+				project_plane_v3_v3v3(v_proj[0], co_prev, v_proj_axis);
 			}
-			while (UNLIKELY(((co_next_ok = (len_squared_v3v3(sv->co_orig_3d, co_next) > eps)) == false) &&
+			project_plane_v3_v3v3(v_proj[2], co_next, v_proj_axis);
+			while (UNLIKELY(((co_next_ok = (len_squared_v3v3(v_proj[1], v_proj[2]) > eps)) == false) &&
 			                ((l_next = l_next->next) != l->prev)))
 			{
 				co_next = slide_origdata_orig_vert_co(sod, l_next->v);
+				project_plane_v3_v3v3(v_proj[2], co_next, v_proj_axis);
 			}
 
-			if (co_prev_ok && co_next_ok && (area_squared_tri_v3(co_prev, sv->co_orig_3d, co_next) > eps)) {
-				const float dist = dist_signed_squared_to_corner_v3v3v3(
-				        sv->v->co, co_prev, sv->co_orig_3d, co_next, f_copy->no);
+			if (co_prev_ok && co_next_ok) {
+				const float dist = dist_signed_squared_to_corner_v3v3v3(sv->v->co, UNPACK3(v_proj), v_proj_axis);
+
 				loop_weights[j] = (dist >= 0.0f) ? 1.0f : ((dist <= -eps) ? 0.0f : (1.0f + (dist / eps)));
+				if (UNLIKELY(!isfinite(loop_weights[j]))) {
+					loop_weights[j] = 0.0f;
+				}
 			}
 			else {
 				loop_weights[j] = 0.0f;