Rigidbody2D climbing 45 degrees slopes

Here are some ideas:

• are you maybe applying the force vector left to right in world space? Then you should rotate the force upwards along the slope. So instead of moving (1, 0, 0), you want to move (0.7, 0.7, 0), or even scale it up to (1, 1, 0), so that you have extra force when going up a slope.

• secondly, you can make the slopes have a PhysicsMaterial that has less or even no friction, so the player slides up more easily.

I hope this helps, if you need any more specific examples, please post some code and maybe show the inspector for your rigidbodies and colliders ;)

I'm adding a small example project of what I mean:

ClimbingSlopes UnityPackage

It's not a complete 2D controller and doesn't feel juicy yet, but it shows the principle. You can also look at the many official Unity tutorials and live trainings about 2D character controllers. Most of the time, you actually don't want to use AddForce, but write all logic yourself and set the position or velocity directly.

Here is just the script if the link goes down:

 using UnityEngine;
 
 public class Movement : MonoBehaviour 
 {
     public LayerMask groundLayerMask;
     public Rigidbody2D rb;
     public float speed = 10f;
 
     void FixedUpdate()
     {
         float input = Input.GetAxis("Horizontal");
 
         // By default we don't want to move.
         Vector2 forceDirection = new Vector2(0, 0);
 
         // Check for ground underneath.
         RaycastHit2D hit = Physics2D.Raycast(transform.position, Vector2.down, 1f, groundLayerMask);
 
         // We can only move when on ground.
         if(hit.collider != null)
         {
             // hit.normal points to the surface upwards direction.
             Debug.DrawRay(transform.position, hit.normal, Color.white);
 
             // If this doesn't point straight up, we are at a slope
             // and should adjust our forceDirection...
 
             // Get a perpendicular vector to the normal.
             // This will point upwards along the slope.
 
             if(input >= 0) // Right
                 forceDirection = new Vector2(hit.normal.y, -hit.normal.x);
             else // Left
                 forceDirection = new Vector2(-hit.normal.y, hit.normal.x);
         }
 
         // Now the green line points in the direction we want to adjust force. 
         Debug.DrawRay(transform.position, forceDirection * Mathf.Abs(input), Color.green);
 
         // We want to scale by the input amount, but not by it's direction
         // because we already picked the direction in our ground check.
         rb.AddForce(forceDirection * Mathf.Abs(input) * speed);
     }
 }

 

I have an idea [untested] [C#]:

Make the player use a stronger movement force when you touch a slope.

 void OnCollisionStay2D(Collision2D coll) {
     if (coll.gameObject.tag == "slope") { //use extra force as long as you're touching a slope
          extraForce = true;
     }
 }

When you are no longer touching a slope, remove the extra force

 void OnCollisionExit2D(Collision2D coll) {
         if (coll.gameObject.tag == "slope")
             extraForce = false;
     }

Now, in the place in your script where you make the player move, add something like this: (I assumed you normally use a force of (1 , 0) when moving the player)

 if (extraForce) {
      Rb2D.AddForce(new Vector2(2, 0.5f) * speed); //Double power + some Y-axis movement
 }
 else {
      Rb2D.AddForce(new Vector2(1, 0) * speed);
 }