[Bf-committers] Speed pass

[Matt Ebb]

On Sun, Jun 26, 2011 at 6:16 AM, Tobias Kummer <supertoilet at gmx.net> wrote:

> Hey there,
>
> I looked around a bit but didn't get any decent info on how blenders
> speed pass is constructed. How are the RGBA values derived from the
> scene according to the movement?
>

As far as I remember, it's 4 floats in image space:

speed[0] displacement from previous frame in X
speed[1] displacement from previous frame in Y
speed[2] displacement to next frame in X
speed[3] displacement to next frame in Y

And you need a z buffer to go along with it too.

cheers

Matt