VFX vector field format

Where can I find the format of the vector field? I would like to generate a field during runtime.
As far as I understood, you need to crerate a 3d texture:

But how do I store the direction and force of a vector?
Thanks.

Actually it is quite easy, after reading [this][1] and [this][2] post, I came up with this code:

Texture3D CreateTexture3D(int size)
{
    Texture3D VectorField = new Texture3D(size, size, size, TextureFormat.RGBAFloat, false);
    VectorField.wrapMode = TextureWrapMode.Repeat;

    Color[] col = new Color[size*size*size];

    for(int i = 0; i < col.Length - 1; i++)
    {
        for(int i = 0; i < col.Length - 1; i++)
            col *= new Color(xmin, ymin, zmin, 1f);*

}
VectorField.SetPixels(col);
VectorField.Apply(false);
return VectorField;
}
Making the undefined vars public and changing them over unity editor shows the effect. They are the axisis and the bigger the value, the stronger the force…
Alpha seems uneeded.
[1]: FGA to 3D Texture question - #2 by MaxProude - Real Time VFX
[2]: .FGA wat iz? - #3 by JangaFX - Real Time VFX