Need help setting maximum slope angle* for jumping

Unity Engine
1

I watched a tutorial and followed it step for step, got everything working up until the Vector3.Angle( , ) part.
Whats suppose to happen is if the angle difference between contact.normal and vector3.up is less than 1 then I should be grounded, but it keeps saying I’m grounded when I jump onto walls even if they’re completely vertical.

So I checked Debug.Log to see what contact.normal says and what Vector3.up says and i get this for Vector3.up: (0,1,0)
and for contact.normal I get (x, y, z) numbers always ranging from -10 to 10.

Does anyone know why this isn’t working, and if not can anyone give insight to a different way to provide limits on angles that can be jumped from.

I removed a few variables and implemented numbers in their place, so that the code is easier to read.


```javascript
private var grounded : boolean;
function Update () {
if (Input.GetButtonDown("Jump") && grounded) {
rigidbody.AddForce (0, 25, 0);
}
Debug.Log (grounded);
}
function OnCollisionStay(collision : Collision)
{
for (var contact : ContactPoint in collision.contacts)
{
{ if (Vector3.Angle(contact.normal, Vector3.up) < 1);      // having trouble with this line
grounded = true;
}
}
}
function OnCollisionExit ()
{
grounded = false;
}
```
2

The code would be much easier to read if you use Code tags (it should be the icon that looks like a paper with writing on it).

Also, can you give a link to the tutorial? There might be a subtlety about it that can explain why you’re experiencing this behavior.

1 Like
3

www.youtube.com : FPS1.5 Jumping the Right Way. Unity3D FPS Game Design Tutorial.
I copied the script as is in the tutorial but it remains nonfunctional, if you know any other methods for setting jump angle peaks that would help

4

You have a semicolon right after your condition in the if statement, so it looks like you’re always considered grounded even when you’re colliding into a surface that doesn’t have a relatively close normal angle to Vector3.up

 if (Vector3.Angle(contact.normal, Vector3.up) < 1)      //remove the semicolon
    grounded = true;

Try that and see if it works out for you.

5

Thanks - I didn’t notice that semicolon after a bit of tweaking it’s all up and working now

6

thank you- but… jumped only once, after nothing

www.youtube.com : FPS1.5 Jumping the Right Way. Unity3D FPS Game Design Tutorial.

this is the code

var walkAcceleration : float = 5 ;
var CameraObject  : GameObject;
var maxWalkSpeed : float = 10;

var horizontalmovement: Vector2;
var jumpVelocity : float = 20;

var grounded : boolean = false;


var maxSlope: float =300;

function Update()
        {
        var rb : Rigidbody;
        rb=GetComponent.<Rigidbody>();

        horizontalMovement = new Vector2(rb.velocity.x,rb.velocity.z);
        if (horizontalmovement.magnitude > maxWalkSpeed)
        {
            horizontalmovement = horizontalmovement.normalized * maxWalkSpeed;
        }

        rb.velocity = new Vector3(horizontalmovement.x,rb.velocity.y,horizontalmovement.y);

        //rb.velocity.x = horizontalMovement.x;
        //rb.velocity.z = horizontalMovement.y;

        transform.rotation = Quaternion.Euler(0,CameraObject.GetComponent(mouselookscript).currentyrotation,0);

        rb.AddRelativeForce(Input.GetAxis("Horizontal")*walkAcceleration,0,Input.GetAxis("Vertical")*walkAcceleration);

////////////////////////////////////////////////// ////////////////////////////////

   

        if(Input.GetButtonDown("Jump")&&grounded)
        {
            rb.AddForce(0,jumpVelocity,0);
        }

    Debug.Log (grounded);

        }

function OnCollisionStay (collision : Collision)
    { 
        for (var contact : ContactPoint in collision.contacts)
    {
        if (Vector3.Angle(contact.normal,Vector3.up)< maxSlope)
        Grounded = true;  
    }

    }

function OnCollisionExit()
        { 
            grounded = false;
        }
7

Code is case-sensitive. When you try to set grounded to true, you used an uppercase ‘G’, which essentially refers to a completely different variable, so grounded remains false while Grounded (which is never accessed when you’re checking if you’re grounded) is true. Fix that to a lowercase ‘g’ and see if that gets you grounded again after the first jump.

The general lesson is that code is very picky. Never underestimate just how precise you have to be to make the code do what you want. :slight_smile:

1 Like
8

Thank you very much for the advice :smile: