Fix Dyntopo detail size preview orientation not matching the cursor

Used the sampled cursor normal when available instead of the raycast face normal.
This makes the preview match the previous orientation of the cursor.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D9460

1 files changed, 10 insertions, 1 deletions

diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index ecd45bfb5e9..604378cd691 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -9514,7 +9514,16 @@ static int dyntopo_detail_size_edit_invoke(bContext *C, wmOperator *op, const wm
   copy_m4_m4(cursor_trans, active_object->obmat);
   translate_m4(
       cursor_trans, ss->cursor_location[0], ss->cursor_location[1], ss->cursor_location[2]);
-  rotation_between_vecs_to_quat(quat, z_axis, ss->cursor_normal);
+
+  float cursor_normal[3];
+  if (!is_zero_v3(ss->cursor_sampled_normal)) {
+    copy_v3_v3(cursor_normal, ss->cursor_sampled_normal);
+  }
+  else {
+    copy_v3_v3(cursor_normal, ss->cursor_normal);
+  }
+
+  rotation_between_vecs_to_quat(quat, z_axis, cursor_normal);
   quat_to_mat4(cursor_rot, quat);
   copy_m4_m4(cd->gizmo_mat, cursor_trans);
   mul_m4_m4_post(cd->gizmo_mat, cursor_rot);