Proper way to swap shaders back and forth?

I need to make a script that changes the shader on all of an objects (and its childrens) renderer to a certain shader, do some stuff, then return it to the original. I know you can procedurally so I don't have to make two prefabs/set of materials but I'm not quite sure what'd be the best way going about this. Anyone got any suggestions?

 

Unless I'm misunderstanding can't you just do something like this (http://docs.unity3d.com/ScriptReference/Material-shader.html) with a foreach statement?

 

Some of my models have 1 material others have 5 sorta thing. I know that's an option but I also know that doing so will make a double of the material meaning double the resources if I don't clear it when I switch back etc. Being that my game is a web build I'd like to keep resource use to a minimum.

 

Oh, that's a tough one but I'll bump the thread at least haha

 

Something I should maybe ask in shader section?

 

Ok. This is the way I've solved the situation. The approach has 1 limitation, while it supports looking into multimaterials for specific shader types, it will not store multiple materials to swap within that multimaterial, as this is not my need, and as this would involve something like dictionary nesting which will for sure complicate the thing I've not done.

My script allows destroyable objects so if you've then make sure it runs the Cleanup method, if not you could delete it.

In my particular case the scene starts with some specific shaders applied for which I look for on start, it stores the renderers of this materials in a dictionary aswell as the original shader and mat in an struct in the value field.

Otherwise if you whant the data to be stored before start you will need a serialiable dictionary and store the data into a file which I'm not in the need for. Not too difficult yet more unnecesary work.

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3. using System.Collections.Generic;
4.  
5. //struct for storing values in dictionary
6. public struct SwapData{
7.     public Material mat;
8.     public Shader shad;
9. }
10.  
11.  
12. public class ShaderSwapper : MonoBehaviour {
13.  
14.     public static ShaderSwapper _SP;
15.  
16.     public Transform MeshesToSwap_root;//the root object where meshes tha will have shader swapped.
17.     private Shader shader0;
18.     private Shader shader1;
19.     private Shader shader2;
20.     private Shader shader3;
21.  
22.     SwapData dat;
23.  
24.     Dictionary <Renderer,SwapData> rendsDic = new Dictionary<Renderer,SwapData>();
25.  
26.     bool swap;
27.  
28.     void Start(){
29. _SP=this;
30.     dat = new SwapData();
31.     //hd shaders
32.     shader0 = Shader.Find("Reflective/Bumped Specular");
33.     shader1 = Shader.Find("Reflective/Bumped Diffuse");
34.     shader2 = Shader.Find("Bumped Diffuse");
35.  
36.  
37.  
38.     //SimpleShader
39.     shader3 = Shader.Find("Diffuse");
40.  
41.     //Populate Dictionary (by default my scenes come with HD shader applied)
42.     Renderer[] rends = MeshesToSwap_root.GetComponentsInChildren <Renderer> ();
43.         foreach (Renderer r in rends) {
44.             foreach (Material m in r.materials){//for multimaterials not skip materials with this shader with index higher than 0
45.                 if (m.shader ==shader0 ||m.shader ==shader1 || m.shader ==shader2){
46.                     if (!rendsDic.ContainsKey (r)){
47.                             dat.mat =m;
48.                             dat.shad =m.shader;
49.                         rendsDic.Add (r,dat); // if not already added, add.
50.                     }
51.                 }
52.             }
53.         }
54.  
55.     }
56.  
57.     //test//test
58.     void Update(){
59.         if (Input.GetKey(KeyCode.O)){
60.             swap =!swap;
61.             Cleanup();
62.             if (swap){        SwapToSDShader ();}
63.             else{             SwapToHDShader();}
64.         }
65.     }
66.  
67.     //IF YOU HAVE DESTROYABLE OBJECTS you need to cleanup the dictionary, if not, you can skip the CLEANUP method.
68.     void Cleanup(){
69.         List<Renderer> null_keys = new List<Renderer>();
70.         foreach (KeyValuePair<Renderer,SwapData> kp in rendsDic) {
71.             if (kp.Key == null){
72.                 null_keys.Add (kp.Key);
73.             }
74.         }
75.  
76.         foreach (Renderer r in null_keys) {
77.             rendsDic.Remove (r);
78.             print (r +" removed ///////");
79.         }    
80.     }
81.  
82.  
83.     void SwapToSDShader (){
84.         //I go trough each Dictionary entry and swap the shader
85.         foreach (KeyValuePair<Renderer,SwapData> kp in rendsDic) {
86.             foreach(Material m in kp.Key.materials){
87.                 if (kp.Key.transform){//if object hast not been destroyed
88.                     if (m.shader ==shader0 ||m.shader ==shader1 || m.shader ==shader2){    
89.                         m.shader = shader3;
90.                     }
91.                 }
92.             }
93.         }
94.     }
95.  
96.     void SwapToHDShader(){
97.         //I go trough each Dictionary entry and restore original HD shader stored in dictionary
98.         foreach (KeyValuePair<Renderer,SwapData> kp in rendsDic) {        
99.             SwapData tempData= kp.Value;
100.             foreach(Material m in kp.Key.materials){
101.                 if (kp.Key.transform){//if object hast not been destroyed
102.                     if(m == tempData.mat){ m.shader = tempData.shad;}
103.                 }
104.             }
105.         }
106.     }
107. }
108.  

Tested under Unity 4.7.2