Script to re-tint an object causing material to be lost when I stop test-running my scene.

In my current project, I have some code for an object that follows the mouse cursor around. I've added a script hook that takes a boolean value, that causes the object to either take a 'castable' value (if you can cast the spell that materializes the full effect), or a 'not castable' color (if you are unable to cast the spell for some reason.)

Code (csharp):

1. using UnityEngine;
2. using System;
3. using System.Collections;
4.  
5. public class SpellTargetingGhost : DebuggableBehavior
6. {
7.     #region Variables
8.  
9.     public float effectDepth = 6.5f;
10.     public string colorProperty = "_TintColor";
11.     public Color castableColor;
12.     public Color notCastableColor;
13.  
14.     private Material _objectMaterial;
15.  
16.     #endregion Variables
17.  
18.     #region Engine Hooks
19.  
20.     public void Start()
21.     {
22.         _objectMaterial = renderer.materials[0];
23.     }
24.  
25.     public void Update()
26.     {
27.         Vector3 pos = Input.mousePosition;
28.         pos.z = effectDepth;
29.         pos = Camera.main.ScreenToWorldPoint(pos);
30.  
31.         transform.position = pos;
32.     }
33.  
34.     public void OnDestroy()
35.     {
36.         DestroyImmediate(_objectMaterial);
37.     }
38.  
39.     #endregion Engine Hooks
40.  
41.     #region Methods
42.  
43.     public void TintByCastability(bool canCast)
44.     {
45.         Color newColor = canCast ? castableColor : notCastableColor;
46.         renderer.material.SetColor(colorProperty, newColor);
47.     }
48.  
49.     #endregion Methods
50. }

Also, the shader I'm using has a _TintColor property on it. This is a modified version of the Particles/Additive Shader....

Code (csharp):

1.  
2. Shader "Particles/Additive-Backculled" {
3.     Properties {
4.        _TintColor ("Tint Color", Color) = (0.5,0.5,0.5,0.5)
5.        _MainTex ("Particle Texture", 2D) = "white" {}
6.        _InvFade ("Soft Particles Factor", Range(0.01,3.0)) = 1.0
7.     }
8.      
9.     Category {
10.        Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" }
11.        Blend SrcAlpha One
12.        AlphaTest Greater .01
13.        ColorMask RGB
14.        Cull Back Lighting Off ZWrite Off Fog { Color (0,0,0,0) }
15.        BindChannels {
16.            Bind "Color", color
17.            Bind "Vertex", vertex
18.            Bind "TexCoord", texcoord
19.        }
20.      
21.        // ---- Fragment program cards
22.        SubShader {
23.            Pass {
24.      
25.                CGPROGRAM
26.                #pragma vertex vert
27.                #pragma fragment frag
28.                #pragma fragmentoption ARB_precision_hint_fastest
29.                #pragma multi_compile_particles
30.      
31.                #include "UnityCG.cginc"
32.      
33.                sampler2D _MainTex;
34.                fixed4 _TintColor;
35.      
36.                struct appdata_t {
37.                    float4 vertex : POSITION;
38.                    fixed4 color : COLOR;
39.                    float2 texcoord : TEXCOORD0;
40.                };
41.      
42.                struct v2f {
43.                    float4 vertex : POSITION;
44.                    fixed4 color : COLOR;
45.                    float2 texcoord : TEXCOORD0;
46.                    #ifdef SOFTPARTICLES_ON
47.                    float4 projPos : TEXCOORD1;
48.                    #endif
49.                };
50.      
51.                float4 _MainTex_ST;
52.      
53.                v2f vert (appdata_t v)
54.                {
55.                    v2f o;
56.                    o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
57.                    #ifdef SOFTPARTICLES_ON
58.                    o.projPos = ComputeScreenPos (o.vertex);
59.                    COMPUTE_EYEDEPTH(o.projPos.z);
60.                    #endif
61.                    o.color = v.color;
62.                    o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
63.                    return o;
64.                }
65.      
66.                sampler2D _CameraDepthTexture;
67.                float _InvFade;
68.      
69.                fixed4 frag (v2f i) : COLOR
70.                {
71.                    #ifdef SOFTPARTICLES_ON
72.                    float sceneZ = LinearEyeDepth (UNITY_SAMPLE_DEPTH(tex2Dproj(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos))));
73.                    float partZ = i.projPos.z;
74.                    float fade = saturate (_InvFade * (sceneZ-partZ));
75.                    i.color.a *= fade;
76.                    #endif
77.      
78.                    return 2.0f * i.color * _TintColor * tex2D(_MainTex, i.texcoord);
79.                }
80.                ENDCG
81.            }
82.        }  
83.      
84.        // ---- Dual texture cards
85.        SubShader {
86.            Pass {
87.                SetTexture [_MainTex] {
88.                    constantColor [_TintColor]
89.                    combine constant * primary
90.                }
91.                SetTexture [_MainTex] {
92.                    combine texture * previous DOUBLE
93.                }
94.            }
95.        }
96.      
97.        // ---- Single texture cards (does not do color tint)
98.        SubShader {
99.            Pass {
100.                SetTexture [_MainTex] {
101.                    combine texture * primary
102.                }
103.            }
104.        }
105.     }
106. }

I've noticed some 'interesting' behavior going on.

First, the first time I use a spell, the material in the prefab for the ghost object in question gets replaced not with an instance of the material, but with 'Type Mismatch'. As soon as I stop running the game, the prefab's material becomes 'Missing.' I can re-assign the saved material, and re-run the game, but every time I stop running, my prefab's material gets nuked again. More interestingly, I don't get a console message alerting me to why the prefab's material has become 'Type Mismatch', during or after execution. The material on the prefab's mesh renderer merely ceases to be.

I did some re-reading on the renderer.material and renderer.materials property, and it seems that it should be instantiating a new instance of the material whenever I call these properties.

What's going on with this code? Do I need to submit a bug, or have I managed to overlook something?

 

I get no problems using your script + shader:

The only edit to the script being:

Code (CSharp):

1. bool clicked;
2. //... Update () { ...
3.         if ( Input.GetMouseButtonDown( 0 ) ) {
4.             clicked = !clicked;
5.             TintByCastability( clicked );
6.         }

 

I wonder if this is related to the fact that I'm instantiating the game object from a prefab? Unlike your example, the ghost effect does not exist in the object hierarchy, until it is brought into being.

 

Still not getting your problem

The fault must be elsewhere in script that you have not posted (maybe the base class [DebuggableBehavior] )

 

DebuggableBehavior only adds a wrapper and some exposed fields for debugging purposes.

Code (csharp):

1. using UnityEngine;
2. using System;
3. using System.Collections;
4.  
5. public abstract class DebuggableBehavior : MonoBehaviour
6. {
7.     #region Enumerations
8.  
9.     public enum LogLevel
10.     {
11.         Information,
12.         Warning,
13.         LogicError,
14.     }
15.  
16.     #endregion Enumerations
17.  
18.     #region Variables / Properties
19.  
20.     public bool DebugMode = false;
21.     public bool ShowTimestamps = false;
22.  
23.     #endregion Variables / Properties
24.  
25.     #region Methods
26.  
27.     public void DebugMessage(string message, LogLevel level = LogLevel.Information)
28.     {
29.         if(! DebugMode)
30.             return;
31.  
32.         if(ShowTimestamps)
33.             message = DateTime.Now.ToString("HH:mm:ss") + ": " + message;
34.  
35.         switch(level)
36.         {
37.             case LogLevel.Information:
38.                 Debug.Log(message);
39.                 break;
40.  
41.             case LogLevel.Warning:
42.                 Debug.LogWarning(message);
43.                 break;
44.  
45.             case LogLevel.LogicError:
46.                 Debug.LogError(message);
47.                 break;
48.  
49.             default:
50.                 throw new Exception("Unexpected log level! " + level.ToString()
51.                                    + Environment.NewLine + " message: " + message);
52.         }
53.     }
54.  
55.     #endregion Methods
56. }

This has nothing to do with my issues, as you can see.

Further I have linked you the entire behavior at this point. The only other things that aren't linked are the code that calls this code, and those are unimportant as those are only hitting methods on the given behavior.