Can I get a script to move an object at a constant speed along an axis?

Questions & Answers
1

I’m trying to balance learning with productivity right now and am having great success finding most of what I need, but cannot find this basic script!

I have some 3D clouds - simple mesh objects - that I’d like to move through the sky at a constant speed.

Would someone be kind enough to write a simple script (public variables would be awesome) to move them along the Z axis? (This is for a 3 minute cutscene, so there’s no need to repopulate or be concerned about the clouds eventually disappearing. I just need them to move very slowly to add life to the scene.)

Thanks so much!

3

And again in C#. This shows the entire class (ie everything that needs to be in the file). Assign speed in the inspector.

using UnityEngine;
using System.Collections;

public class MoveScript : MonoBehaviour {

public float speed;

    void Update() {
        transform.Translate(Vector3.forward * Time.deltaTime * speed);
    }
}
2

function Update() {
// Move the object forward along its z axis 1 unit/second.
transform.Translate(Vector3.forward * Time.deltaTime);
// Move the object upward in world space 1 unit/second.
transform.Translate(Vector3.up * Time.deltaTime, Space.World);
}

5

If the object has a rigidbody change the velocity directly
For example:
rb.velocity = movePos * speed;
//no need for time.deltaTime

4

There are no global variables in C# like in line 4:
public float speed;

The use of public modifier hints you there is something wrong here: make no sens to make a global variable public - after all what does it even mean for a global variable to be private?

This variable should be a field of your MoveScript class. This will fix the error.

Tip: It’s a bad practice to have public fields in general. Better way to expose a field in inspector is to use the SerializeField attribute ( Unity - Scripting API: SerializeField ):

using UnityEngine;
using System.Collections;

public class MoveScript : MonoBehaviour {

   [SerializeField]
   private float speed;

   void Update() {
      transform.Translate(Vector3.forward * Time.deltaTime * speed);
   }
}