Regarding making forces and velocity zero in a particular direction

Dear all,
I want to make forces and velocity zero in a particular direction. Enforce2d command is used in 2 dimensional .If I want to make forces and velocity zero in particular direction in 3d region,for this which command can be used?

With Regards,
Ritesh Satwani

There is fix setforce which can do this for you. As long as the initial velocities are zero they will remain zero. I’m not sure if this is still true if rigid bodies are involved, but as long as they aren’t, it should be fine.