Fix a bug when a tutorial generates a lot of pictures
Fix a bug when a tutorial generates a lot of pictures

karies/root,root-mirror/root,karies/root,root-mirror/root,olifre/root,root-mirror/root,karies/root,olifre/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,karies/root,karies/root,karies/root,olifre/root,olifre/root,karies/root,olifre/root,karies/root,karies/root,karies/root,olifre/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,karies/root,olifre/root