How to make parts go down to the floor or terrain?

  1. What do you want to achieve? Keep it simple and clear!
    I want to make parts scale down until they reach the terrain or floor(part)

  2. What is the issue? Include screenshots / videos if possible!
    I dont know how to make it scale until it reaches a part or terrain

  3. What solutions have you tried so far? Did you look for solutions on the Developer Hub?
    I have tried YT and Devforum

Heres a picture: i want the bottom of those models to go to that part below it (each leg of the model is an individual part)