This is a straightforward extension of the 2D translation transformation:
(1 0 0 0) (x' y' z' 1) = (x y z 1) * (0 1 0 0) (0 0 1 0) (Tx Ty Tz 1) which gives: x' = x + Tx y' = y + Ty z' = z + Tz
Note: to do an inverse Translation in 3D, replace Tx with -Tx, Ty with -Ty, and Tz with -Tz then T (T-1) = 1 (identity matrix)