I can do this in a bluprint:
- Get the coordinates of the contact (the place where the effect appears,
- Subtract the coordinates of the center of the wheel from it, while getting a few centimeters of indentation in X and/ or Y
- Calculate the angle of the wheel slope using the difference as a cathet, and the difference in Z as a hypotenuse.
- apply this angle as a rotation for the niagara effect on this contact spot
It’s difficult, interesting, but surely everything is much simpler?