Correctly move rigidbody at constant speed

Questions & Answers
1

this is currently my code. The object moves at the desired speed but using [rb.velocity = movement * speed] if it jump it remains glued to the ground. I can’t understand how I can fix things.

private Vector3 movement;
private float speed = 3;
public bool isGrounded;

void Start()

rb = GetComponent<Rigidbody>();

void Update()
{
float Horizontal = Input.GetAxis("Horizontal");
float Vertical = Input.GetAxis("Vertical");
movement = transform.right * Horizontal + transform.forward * Vertical;
float origMagnitude = movement.magnitude;
movement.y = 0.0f;
movement = movement.normalized * origMagnitude;

if(isGrounded && Input.GetKeyDown(KeyCode.Space))
rb.AddForce((Vector3.up + movement) * JumpForce, ForceMode.Impulse);

RaycastHit hit;
if (Physics.Raycast(transform.position, transform.TransformDirection(Vector3.down), out hit, rayDistance, layer)) isGrounded = true;
else isGrounded = false;
}

private void FixedUpdate ()
{      
     rb.velocity = movement * speed;
}
2

By doing movement.y = 0.0f and passing the entire movement Vector3 to your rb.velocity, you are basically denying your rigidbody physics on Y axis, this is what you should do:

using UnityEngine;

public class pappaController : MonoBehaviour
{
    public float speed = 10f;
    public float jumpForce = 5f;
    public float rayDistance = 5f;
    public LayerMask WhatIsGround;

    private Rigidbody rb;
    private Vector3 movement;
    private bool isGrounded;

    void Start()
    {
        rb = GetComponent<Rigidbody>();
    }

    void Update()
    {
        float Horizontal = Input.GetAxis("Horizontal");
        float Vertical = Input.GetAxis("Vertical");            
        movement = (transform.right * Horizontal + transform.forward * Vertical) * speed; // multiply by speed and you got your movement ready
        // removed this part, don't know what was the point of it

        if (isGrounded && Input.GetKeyDown(KeyCode.Space))
            rb.AddForce(Vector3.up * jumpForce, ForceMode.Impulse);

        RaycastHit hit;
        isGrounded = Physics.Raycast(transform.position, transform.TransformDirection(Vector3.down), out hit, rayDistance, WhatIsGround);
    }

    private void FixedUpdate()
    {
        // y axis -> rb.velocity.y
        rb.velocity = new Vector3(movement.x , rb.velocity.y, movement.z);
    }
}