Custom part cooling fan curve

[katherinehackworth]

Is your feature request related to a problem? Please describe.
Fan speed can only be set to a given percentage for the part cooling fan.

Describe the solution you'd like
The ability to set a custom fan curve, defining part cooling fan speeds based on the overhang angle of the part at that current area as so: This is similar to how PC users are able to set custom fan curves for their PC case fans as a function of the (usually) CPU temperature.

Describe alternatives you've considered
Unsure.

Affected users and/or printers
All users with part cooling fans on their printers.

Additional context
N/A

[Ghostkeeper]

From a user experience point of view, I think this would require some sort of tiered UI that allows people to use a simple version first without needing to understand these graphs. Otherwise this setting would not be understood by many users, and some users might bulk at the complexity.

[mrx23dot]

+1 for overhang based fan control, I need 100% fan for overhangs, but 0% fan for the rest of layers with ABS.

[halfshavedyaks]

I also want overhang fan control, but it needn't be a custom curve. As mrx23dot has said, one setting for any overhangs above a certain threshold would be adequate in many cases, analogous to the overhang speed setting. A default smooth gradient might be better still and a custom curve would be icing, but a basic version would do most of what I need.

[Ghostkeeper]

Something similar is being discussed in #5140, Halfshavedyaks.

[GregValiant]

See Pull request #15853