mirroring model manipulation on a single model

snake85027

Just have a question on the (reform) paint deform tool in 3ds max. When I am using these tools to manipulate my model, how can I mirror my actions on the axis like in zbrush...and i do not mean using a mirror modifier... i could have swore I saw something like this and now I can not find it.

passerby

add the symmetry modifier first