There is mentioning several methods of color stops interpolations.
B-Spline:
Uses a B-spline interpolation for the color stops.
Cardinal:
Uses a cardinal interpolation for the color stops.
Linear:
Uses a linear interpolation for the color stops.
Ease:
Uses an ease interpolation for the color stops.
Constant:
Uses a constant interpolation for the color stops.
The one I donāt understand is the āCardinal interpolationā. Could anyone know what it means and possibly give me a link to some documentations regarding to the method please?
Thank you ever so much for this link. It really helped me to realise what is this I am looking at. I was wondering so exactly what is the difference from āCardinalā to āEaseā for instance? I messed with the Color Ramp here and this is āEaseā
To be honest, though I saw some changes, I am clueless as to what and why the name āCardinalā actually. Do you know what is the difference? I know the difference might be in the way it is calculate the curveās tangent, but why the name āCardinalā?
Itās given the name Cardinal because itās a Cardinal math function, following the formula I listed above. Itās nothing special, just the name of the formula
As Joseph has suggested above - is just the name of the function, nothing special besides it. If you really want to clarify that question, you could give it a try and ask Blenderās developers itself. Hereās the link anyway: https://developer.blender.org/
From what Iāve found, the Cardinal name might have some ties with the Cardinality, see here.
At the end of the day, I think the name Cardinal was given because of the math function that somehow must be related to what it actually does with the colorsā spectrum in Blender.
I can assume that the main difference between Ease and Cardinal is that Ease gives more smooth transition between multiple colors. The name itself is also used in CSS (Cascading Style Sheets), where, thanks to Ease, you are able to create smooth fade-in/fade-out animations with blocksā appearances.
@HoangDuyTran This is a rather complex topic. At its very basic these are different methods of value interpolation. Cardinal interpolation uses cardinal spline calculations to interpolate. And no the spline function itself is no cardinal function. Cardinality is rather about where splines tangents are calculated from. That are cardinal points. In the end its a simplified spline with just a tension parameter to control the smoothness or tangents lengths. It has advantages and drawbacks in relation to other splinetypes, but thats nothing we can disuss here in a couple of minutes. But opposing to a b spline the cardinal inperpolation always goes trough its controlpoints. Ease in and out on the other hand are even less they are just accelerating or decelerating functions between two points. They may look similar in some cases to cardinal spline interpolation but they are not.
By seeing this video (https://youtu.be/jvPPXbo87ds) and combining your message I understood why it was called āCardinalā because as you have said itās controlling points of the splines. Thank you for confirming this for me.
