Double Jump Like Mario?

[Cy8ro2]

i have been trying for hours trying to have a double jump or triple jump like mario where he does a normal jump and if you are going fast enough your jump height gets bigger. i sadly havent succeeded in doing this task? can someone help me on how to do a mario like double jump?

[EvilCleric]

jump_height = f(character_velocity):

[Cy8ro2]

thank you so much but how would i put animations on each seperate jump?