Why is this script slowing down the gravity of a rigidbody?

Physics
1

So the problem is that when I have the first 3 lines of code in there, the gravity is cut down most of the way and my character falls slowly, also the jump part of the code stops working. When I jump it moves up about .1 on the y axis, then starts falling slowly back to the ground. But when I have line 1-3 commented out the jump script works.

Is there something I can do to line 3 so I can keep line 1-2 the same and for the jump to work?

(Speed is set to 10.0F)

        Vector3 forwardVel = transform.forward * speed * Input.GetAxis ("Vertical");
         Vector3 horizontalVel = transform.right * speed * Input.GetAxis ("Horizontal");
         GetComponent<Rigidbody>().velocity = forwardVel + horizontalVel;
//Jump
    if (rb.velocity.y == 0 && Input.GetButtonDown("Jump"))
         {

                 rb.AddForce(new Vector3(0, 5, 0), ForceMode.Impulse);   
         }
2

Hm… maybe it’s gravity? Did you change the parameter of gravity? You can change it from Editor or script. Check Physics.gravity value.

3

The physics system adds the gravity force to the Rigidbody velocity. You’re completely overwriting the Rigidbody velocity here:

GetComponent<Rigidbody>().velocity = forwardVel + horizontalVel;

Later you do this:

rb.AddForce(new Vector3(0, 5, 0), ForceMode.Impulse);

Do you know what an impulse force is? It adds the force you specify onto the velocity of the Rigidbody immediately i.e. velocity += force.

This is what you should be doing above instead of overwriting the Rigidbody velocity. Either that or you can simply add your ‘forwardVel + horizontalVel’ to the velocity.

4

So apply impulse force for both horizontal and vertical forces?

5

Whelp, I tested this, and now I have another problem. It applys it globally, but I need it to apply it locally because my player rotates. How can I do the impulse force and apply it locally?

6

If rotating is problem, consider constraints of rigidbody.

7

Great that you test “this” but unfortunatley we can’t see your code. You obviously apply an impulse force in local-space by passing it a local-space vector just like you did when you set a local-space vector for the velocity. Nothing changes.

Note that you’re using Vector3 which might be convenient but 2D requires a Vector2. It performs a conversion for you by simply stripped the Z away but note that this can cause subtle problems if you’re not using vectors aligned to the XY plane.