C# - Instantiate Prefab with random color

Hi there,

This is my first post ! Nice to meet you all
I'v been learning C# for a week, and i'm trying to instantiate prefabs with random colors, but can't figure out how to do it.

Here is the code, a simple function that creates a grid of Gameobjects.

Code (CSharp):

1. public class Grid : MonoBehaviour {
2.  
3.     public Vector3 Grid_Size;
4.     public GameObject Prefab_Sol;
5.  
6.     // Use this for initialization
7.     void Start () {
8.  
9.    
10.         CreateGrid ();
11.  
12.     }
13.  
14.     void CreateGrid () {
15.    
16.         for(int x = 0; x < Grid_Size.x; x++){
17.             for(int z = 0; z < Grid_Size.z; z++){
18.                 Instantiate(Prefab_Sol, new Vector3(x,0,z), Quaternion.identity);
19.  
20.             }
21.  
22.  
23.         }}
24. }
25.  

I would like to create randomly black or white gameobjects.
I'v tried to do it with a if() function in CreateGrid(), but then all the instantiated prefabs have the same color...
Can someone give me a clue ?

Thanks a lot !

 

Code (CSharp):

1. GameObject go = Instantiate(Prefab_Sol, newVector3(x,0,z), Quaternion.identity) as GameObject;
2. go.GetComponent <MeshRenderer> ().material.color = newColor (Random.Range (0, 1), Random.Range (0, 1), Random.Range (0, 1), Random.Range (0, 1));

 

Hey Smitchell,

Thanks for the tip.
Something weird : your method always gives black gameobjects.
If i replace Random.Range(0, 1) by Random.Range(0F, 1F), i can see the code is working (every Gameobject has a different color).

What am i missing ?

 

oh crap yeah, if you give random a int, it'll return a int. So what I wrote will always give you 0 or 1, yeah change it to 0.0f and 1.0f and it should work.

What do you mean? Does it not work how you wanted it to?

 

Yep get it.
Actually i would like get black or white gameobjects only. With float numbers i get plenty of ugly colors

 

you could do something like:

Code (CSharp):

1. Color col = Random.Range (0, 2) == 1 ? Color.black : Color.white;
2. go.GetComponent<MeshRenderer>().material.color = col;

(untested)

 

Working perfectly !
Now i'll be able to use the ?: operator, thanks a lot !

 

Hey again !

I'v tried replacing gameobjects i instantiate by imported .obj and i have this 'No MeshRenderer error'
http://s15.postimg.org/cg2nod0uz/Capture_d_cran_2014_09_17_10_02_02.png

When i check its components i can see 'Mesh Renderer':
http://s30.postimg.org/3rfqq7bo1/Capture_d_cran_2014_09_17_10_05_50.png
By the way, why are its components grey ?

So i tried with a prefab. But then i noticed the mesh became a child of the prefab:
http://s29.postimg.org/65ur86ghz/Capture_d_cran_2014_09_17_10_09_38.png

Code (CSharp):

1. GO.GetComponent<MeshRenderer>().material.color = col;

doesn't work anymore, all the prefabs have the same color (default).

So i thought i had to access the child and i replaced:

Code (CSharp):

1. GO.GetComponent<MeshRenderer>().material.color = col;

by

Code (CSharp):

1. void CreateGrid () {
2.  
3.         for(int x = 0; x < Size.x; x++){
4.             for(int z = 0; z < Size.z; z++){
5.                 GameObject GO = Instantiate (Prefab_Sol, new Vector3(x,0,z), Quaternion.identity) as GameObject ;
6.                 Color col = Random.Range (0, 2) == 1 ? Black : White;
7.                 GO.GetComponentsInChildren<MeshRenderer>().material.color = col;
8.  
9.  
10.  
11.         }
12.     }
13. }
14. }

but then i have this error (no definition for material):
http://s29.postimg.org/ntzzmgq9z/Capture_d_cran_2014_09_17_10_17_55.png

Dont get it...

Thanks a lot for your help !

 

I need more information, unity has told you why it doesn't work. There isn't a mesh renderer, but lets figure out why there isn't one.

When you instantiate the prefab, look in the hierarchy; is your mesh a child of the instantiated prefab? or?

Screen shot it

 

Hey,

Yep its a child of the prefab :
http://s28.postimg.org/qk0352yel/Capture_d_cran_2014_09_17_10_36_08.png

It finally works using:

Code (CSharp):

1. GO.transform.Find ("default").renderer.material.color = col;

But i would like to understand why

Code (CSharp):

1. GO.GetComponentsInChildren<MeshRenderer>().material.color = col;

didnt work ?

I mean unity tell me there isnt a mesh renderer but i clearly see it on the object :
http://s2.postimg.org/pixkqm26x/Capture_d_cran_2014_09_17_10_44_14.png
Really dont get it

 

because that is looking for all the components in all the children, it returns an array of components.

You'd have to do something like:

MeshRenderer childRendere = go.gameObject.GetComponentInChildren <MeshRenderer> () ... etc

 

look at it carefully, it's different