Beginner B15 – Adding Components via Script
How to add a component to an object using scripting, and ensure it isn’t added more than once.
Code Used (Javascript)
function OnCollisionEnter (myCollision : Collision) {
-
if(myCollision.gameObject.name == "Platform"){
-
if(!myCollision.gameObject.rigidbody){
-
myCollision.gameObject.AddComponent(Rigidbody);
-
}
-
}
-
}
Further Reading
21 Comments
Leave a Comment
Hi, I have a problem here. I tried attaching the addComp script to a gameObject in the scene and it works fine when colliding. However when I tried to attach the addComp script to a prefab, ie. bullet, it wont work. Have I done something wrong? Please advise. Thanks.
Hi Jay, post your script via pasteit4me.com and post a link here so we can all take a look at it please!
Hi wgstone,
Still no luck…:(
I changed the code to:
function OnCollisionEnter (myCollisions : Collision) {
if(myCollisions.gameObject.name == “Cube1″){
var myCounter : GUITextScript = gameObject.Find(“GUITextScript”).GetComponent(“Counter”);
myCounter.Counter+1;
}
}
I get a: “BCE0034: Expressions in statements must only be executed for their side-effects.”
I googled the error and it means: “The compiler assumes that statements which contain nothing but values and which don’t have any side effects (no function calls or assignment) are a mistake and emits an error accordingly.”
Still, I have NO IDEA what to do…Help please??
Sorry, wrong page…reposting it to the correct one…(I need rest…)
Excellent code, very clever. The if statement is because it collides several times?
Precisely, the script then only attempts to add a rigidbody if it does not find a rigidbody.
var TriggerSign : gameObject;
var signWarning : gameObject;
function OnCollisionEnter( myCollision : Collision ){
if(myCollision.gameObject.name == “TriggerSign”){
Instantiate (signWarning);
}
triggersign is e name of my cube(gameobject)
signWarning is e name of my sign(gameObject)
car is my player(gameObject)
what i want to do is on the collision of my car with the cube , signWarning(sign) will appear but the codes doesn’t seems to work . what went wrong . hopefully u guys can help thanks you
Don – you haven’t written the Instantiate command properly, take a look at the video here on how to do that, if you’ve reached B15 then you should have already encountered it. Also if your triggersign object has a collider set to trigger, then you should use OnTriggerEnter, not OnCollisionEnter.
if i use OnTriggerEnter then how do i code it? really thanks a ton for your help
is this the right way?
var signWarning : GameObject;
function OnTriggerEnter (myTrigger : Collider) {
if(myTrigger.gameObject.name == “TriggerSign”){
var instance : GameObject = Instantiate(signWarning, transform.position, transform.rotation);
}
}
looks okay to me don, whats the context?
hmmm the problem’s solved already thank alot… anw i jus wanna ask if it is possible for ontriggerenter event to work… when ontrigger i start my timer?becus i tried doing that but the timer only records the time my car collides with my cube and exiting it..
Hi Don, yes you’re not considering when the functions occur – you need to update time based stuff in an Update() or FixedUpdate() function, so to get a timer to start when the trigger collision occurs, simply make a boolean flag variable to set to true when you collide, and only add to the timer when this variable becomes true. Does that make sense?
ok i almost get what u’re trying to say… so my update function will have to be under the same script or do i hav to create another script den when my car collides and triggers e cube i add in a line and call my function in my script?
What if you wanted to do the opposite? and remove a component such as a box collider?
To remove a component use GetComponent within a Destroy command, eg. Destroy(gameObject.GetComponent(Rigidbody)); for example, good luck!
hi. i have a problem.
i want to add a mesh collider to a dynamic gameobject.
var mygameobject : GameObject;
mygameobject = new GameObject();
mygameobject = Instantiate(aPrefab, jugador.transform.position, jugador.transform.rotation);
mygameobject.AddComponent(MeshCollider);
mygameobject.GetComponent( Transform).localScale = new Vector3(3.5, 3, 3.5);
But it didn’t work.
help please.
Take care.
hi. i have a problem.
i want to add a mesh collider to a dynamic gameobject.
var mygameobject : GameObject;
mygameobject = new GameObject();
mygameobject = Instantiate(aPrefab, jugador.transform.position, jugador.transform.rotation);
mygameobject.AddComponent(MeshCollider);
mygameobject.GetComponent( Transform).localScale = new Vector3(3.5, 3, 3.5);
But it didn’t work.
help please.
Take care.
What does happen here? Always mention what occurs when asking otherwise it’s not always a singular finite answer.
In C#, it has to be “Rigidbody” withing quotes. Otherwise, it says that AddComponent requires a value not a type.
I did a really cool domino effect using multiple domino pieces which I called “dom”. I applied this script only to the first object.
function OnCollisionEnter (domCollision : Collision) {
if(domCollision.gameObject.name == "dom"){
if(!domCollision.gameObject.rigidbody){
domCollision.gameObject.AddComponent(Rigidbody);
}
if(!domCollision.gameObject.DominoAdd){
domCollision.gameObject.AddComponent(DominoAdd);
}
}
}