3D trajectory (more physics)

[RipX]

P.S. Considering, scale is difficult to understand what you mean since your comment is ambiguous. The vectors values should not change with scaling, the position of your objects should be scaled instead. For this in a 3d sence, you would use a scale matrix, this is usually defined as a 3x3 matrix or 4x4 homogeneous matrix such that the values are as follows (the next matrix is commonly used, but you can do it column or row major, up to you):

sx, 0, 0, 0
0, sy, 0, 0
0, 0, sx, 0
0, 0, 0, 1

KEY
++++++++++++++++
sx = scale x
sy = scale y
sz = scale z
++++++++++++++++

now your vectors can be multiplied by this matrix, ultimatly resulting in your position information.

RipX