How do I Change Camera Background in a Loop Multiple Times?

Hello Unity Forum

I am attempting to setup the background color of my camera so that it changes to several different colors in a loop. I can set it up to lerp between just two colors with math.pingpong but I can't figure out how to make it change in to several different colors to create a more interesting background that fits the theme of the game a bit better. I'm experimenting with this right now but it leaves it as white when I begin the application.

Code (CSharp):

1. void Awake () {
2.         camera.backgroundColor = Color.white;
3.         }
4.  
5. void Update() {
6.         if (camera.backgroundColor == Color.white) {
7.             camera.backgroundColor = Color.Lerp (Color.white, Color.green, Time.time *.1f);
8.         }
9.         if (camera.backgroundColor == Color.green) {
10.             camera.backgroundColor = Color.Lerp (Color.green, Color.white, Time.time *.1f);
11.                 }
12.     }
13. }
14.  

 

There is something wrong with your code.

At the first Update step, your code will enter the first if statement, changing the color of your background to something near white. On its next update step, the code will enter neither of your if statements, thus your background is stuck to its near white color.

Try using Coroutine to sequence the transition of the colors. Something like

Code (CSharp):

1. IEnumerator ColorTransition()
2. {
3.     while(camera.backgroundColor != Color.green)
4.     {
5.         camera.backgroundColor=Color.Lerp(Color.white, Color.green, Time.time*.1f);
6.         yield return null;
7.     }
8.  
9.     while(camera.backgroundColor != Color.white)
10.     {
11.         camera.backgroundColor=Color.Lerp(Color.green, Color.white, Time.time*.1f);
12.         yield return null;
13.     }
14. }

 

Okay I tried that and I messed around with it a bit. What happens is that it changes to green slowly, then instantly changes to white. I'm very new to programming and although I've read the Unity guide to IEnumerators I still have a hard time really understanding them. I could use more help if possible, maybe another solution? My end goal here is to have it switch between about 8 different colors via lerp, and if possible in a random order.

 

Hi, I wanted something similar so I created a script for it.


1. Populate the color list with two or more colors.
2. Select a transition time (can not be 0).
3. Select random colors or not.



Here is the script. You can always alter it, if it's not exactly what you are looking for.

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3. using System.Collections.Generic;
4.  
5. public class BackgroundColorScript : MonoBehaviour {
6.  
7.     public List<Color> colorList = new List<Color>();
8.     public float transitionTime = 1f;
9.     public bool randomColor = false;
10.  
11.     private int colorIndex = 0;
12.     private int nextColorIndex = 0;
13.  
14.     //Init
15.     void Awake() {
16.         camera.backgroundColor = colorList[colorIndex];
17.  
18.         //Sets next color index
19.         if(randomColor)
20.         {
21.             while(nextColorIndex == colorIndex)
22.             {
23.                 nextColorIndex = Random.Range(0, colorList.Count);
24.             }
25.         }
26.         else
27.         {
28.             nextColorIndex += 1;
29.             if(nextColorIndex >= colorList.Count)
30.             {
31.                 nextColorIndex = 0;
32.             }
33.         }
34.  
35.         //start transition if there are more than 1 colors in list
36.         if(colorList.Count > 1)
37.         {
38.             StartCoroutine(ColorTransition());
39.         }
40.         else
41.         {
42.             Debug.LogWarning("Not enough colors in list.", this);
43.         }
44.     }
45.  
46.     IEnumerator ColorTransition()
47.     {
48.         //Init color transition
49.         float delta = 0f;
50.  
51.         //color transition
52.         while(delta < 1f)
53.         {
54.             delta += Time.deltaTime / transitionTime;
55.             camera.backgroundColor=Color.Lerp(colorList[colorIndex], colorList[nextColorIndex], delta);
56.             yield return new WaitForEndOfFrame();
57.         }
58.         camera.backgroundColor = colorList[nextColorIndex];
59.  
60.         //Sets next color index
61.         colorIndex = nextColorIndex;
62.         if(randomColor)
63.         {
64.             while(nextColorIndex == colorIndex)
65.             {
66.                 nextColorIndex = Random.Range(0, colorList.Count);
67.             }
68.         }
69.         else
70.         {
71.             nextColorIndex += 1;
72.             if(nextColorIndex >= colorList.Count)
73.             {
74.                 nextColorIndex = 0;
75.             }
76.         }
77.  
78.         //starts a new color transition
79.         StartCoroutine(ColorTransition());
80.     }
81. }

 

Wow that's a really well made script worked perfectly and easily. Thanks! I'm going to have to study it a bit to figure out how it works but it does what I need it to perfectly.

 

When I used this code for my 2d sprite renderer component the sprite is vanishing. However i can see the color transition in the inspector

 

Code (CSharp):

1. using UnityEngine;
2.  
3. public class ChangeColours : MonoBehaviour {
4.     public Color color1 = Color.green;
5.     public Color color2 = Color.blue;
6.     public float duration = 3.5F;
7.  
8.     public Camera cam;
9.  
10.     private void  Update() {
11.         var t  = Mathf.PingPong(Time.time, duration) / duration;
12.         cam.backgroundColor = Color.Lerp(color1, color2, t);
13.     }
14. }