How to shoot particle like projectile? - unity3d

Question

I made a tank that shoot sphere balls on mouse click.
my C# script:
GameObject prefab;
// Use this for initialization
void Start () {
prefab = Resources.Load("projectile") as GameObject;
}
// Update is called once per frame
void Update() {
if (Input.GetMouseButtonDown(0))
{
GameObject projectile = Instantiate(prefab) as GameObject;
projectile.transform.position = transform.position + Camera.main.transform.forward * 2;
Rigidbody rb = projectile.GetComponent<Rigidbody>();
rb.velocity = Camera.main.transform.forward * 40;
}
}
in this script im shooting a mesh named projectile. But I want to shoot a particle ball and not a mesh. I already tried to change the particle to Orbparticle on script but no object was spawned. What im doing wrong?

Answer 1

No object was spawned because you probably don't have a resource called Orbparticle. Check if you have any errors when you run your script. If Resources.Load doesn't find the object you want by the path you gave it, it will give null, which probably why no object is being spawned.
If you want to shoot a particle instead of a mesh then what you need to do is set prefab to a GameObject you prepared ahead of time that has the ParticleSystem you want. I'd suggest against using Resources.Load for this.
1. Using Resources.Load.
Change your code to this so that it will alert you if it doesn't find the resource:
GameObject prefab;
// Use this for initialization
void Start () {
string name = "OrbParticle";
prefab = Resources.Load<GameObject>(name);
if (prefab == null) {
Debug.Error("Resource with name " + name + " could not be found!");
}
}
// Update is called once per frame
void Update() {
if (Input.GetMouseButtonDown(0))
{
GameObject projectile = Instantiate(prefab) as GameObject;
projectile.transform.position = transform.position + Camera.main.transform.forward * 2;
Rigidbody rb = projectile.GetComponent<Rigidbody>();
rb.velocity = Camera.main.transform.forward * 40;
}
}
Now in order for this to work you need a prefab called "OrbParticle" or whatever string you set the variable name to. Resources.Load looks for items in paths such as Assets/Resources. So you MUST have your "OrbParticle" prefab located in that Resources folder. Unless you have a specific reason for using Resources.Load, I strongly suggest you go with solution 2.
2. Ditching Resources.Load and using the Prefab directly.
Change your code to this:
public GameObject prefab;
// Update is called once per frame
void Update() {
if (Input.GetMouseButtonDown(0))
{
GameObject projectile = Instantiate(prefab) as GameObject;
projectile.transform.position = transform.position + Camera.main.transform.forward * 2;
Rigidbody rb = projectile.GetComponent<Rigidbody>();
rb.velocity = Camera.main.transform.forward * 40;
}
}
Then do this:
Create a new empty GameObject.
Attach a ParticleSystem to the GameObject.
Make a new prefab asset.
Drag and drop the newly created GameObject into a Prefab asset.
Drag and drop the the prefab into prefab field in your Monobehaviour (the object doing the shooting. It will have a prefab field in the Inspector. That's why we set prefab to be a public field).
If you continue having problems, look in Unity's Hierarchy to see if no object is being created at all. It might be the case that it is instantiating a GameObject but the GameObject is invisible for some reason or not instantiating in the location you expect.