Resolved Easing function used in SIGGRAPH 2019 Reactor vehicle camera talk?

Hi,
I'm wondering if anyone can figure out which function was used for the Reactor Remap node curves in @Adam_Myhill's SIGGRAPH 2019 talk on vehicle cameras (

, curve shape driven by A, B, Bias)?
(b+a-2)x^3 + (-2a-b+3)x^2 + ax (https://mobile.twitter.com/FarbsMcFarbs/status/1456830625617432576) seems good for the a and b (maybe?), but I can't figure out the Bias parameter.

 

Belated thanks! With this, and some help from some awesome maths people, I can now answer my own question.
This function seems like a perfect match for the curves: https://www.desmos.com/calculator/ocvtvmwdyp


I've had a good verify of the function above, by overlaying the desmos graphs over the ones from the video.
I implemented it like this, which I've eye-checked side-by side, but I've not done actual overlays

Code (CSharp):

1. //https://www.desmos.com/calculator/ocvtvmwdyp
2. //Tested for 0<=t<=1; 0<=a<=1; 0<=b<=1; -1<=Bias<=1
3. float CustomEasing( float t, float a, float b, float Bias ) {-1<=Bias<=1
4.     var Bt = t / ( ( ( 1f / ( .5f - ( Bias / 2f ) ) ) - 2f ) * ( 1 - t ) + 1f ); //Biased T;
5.     var y = ( 3*b + 3*a - 2 ) * Bt*Bt*Bt + ( -6*a - 3*b + 3 ) * Bt*Bt + 3*a*Bt;
6.     return y;
7. }