How to calculate the motion vector?

Question

Unity

I am currently making my PlayerController based on a Rigidbody. I move on an inclined surface, and depending on the slope I move not only in x and z, but also in y:

Here is my code:

float groundAngle = (float)System.Math.Acos(Mathf.Clamp(groundNormal.y, -1, 1)) * 180 / (float)System.Math.PI;
rigidbody.AddRelativeForce((direction + Vector3.up * groundAngle / 45) * speed, mode);

But this method is only suitable if the player is moving straight up the hill. But it can also go down or go along an inclined surface. In general, I want to calculate the motion vector, knowing where the player will go and the normal of the surface.
PS direction - the player's local direction.

Answer 1

If you have a PlayerController with a collider + Rigidbody and a collider on a supporting surface, it's enough to apply force just in the direction of view. (transform.forward) Uphill or downhill movement will be decided by the physics engine itself.