Making the Particle Additive Shader be affected by default Fog

Hi,

I'm using the Particle/Additive (Soft) Shader from Unity 4.6.3, but it doesn't seem to be affected by the scene Fog:



I have some path points there that shouldn't be so easily visible from this distance.

Those are combined, relatively complex Shuriken FX with the abovementioned shader applied to all of them.

Is it possible to make them blend with fog?

Here's the original full shader I'm using:

Spoiler

Code (csharp):

1.  
2. Shader "Particles/Additive (Soft)" {
3. Properties {
4.     _MainTex ("Particle Texture", 2D) = "white" {}
5.     _InvFade ("Soft Particles Factor", Range(0.01,3.0)) = 1.0
6. }
7.  
8. Category {
9.     Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" }
10.     Blend One OneMinusSrcColor
11.     ColorMask RGB
12.     Cull Off Lighting Off ZWrite Off Fog { Color (0,0,0,0) }
13.  
14.     SubShader {
15.         Pass {
16.  
17.             CGPROGRAM
18.             #pragma vertex vert
19.             #pragma fragment frag
20.             #pragma multi_compile_particles
21.  
22.             #include "UnityCG.cginc"
23.  
24.             sampler2D _MainTex;
25.             fixed4 _TintColor;
26.    
27.             struct appdata_t {
28.                 float4 vertex : POSITION;
29.                 fixed4 color : COLOR;
30.                 float2 texcoord : TEXCOORD0;
31.             };
32.  
33.             struct v2f {
34.                 float4 vertex : SV_POSITION;
35.                 fixed4 color : COLOR;
36.                 float2 texcoord : TEXCOORD0;
37.                 #ifdef SOFTPARTICLES_ON
38.                 float4 projPos : TEXCOORD1;
39.                 #endif
40.             };
41.  
42.             float4 _MainTex_ST;
43.    
44.             v2f vert (appdata_t v)
45.             {
46.                 v2f o;
47.                 o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
48.                 #ifdef SOFTPARTICLES_ON
49.                 o.projPos = ComputeScreenPos (o.vertex);
50.                 COMPUTE_EYEDEPTH(o.projPos.z);
51.                 #endif
52.                 o.color = v.color;
53.                 o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
54.                 return o;
55.             }
56.  
57.             sampler2D_float _CameraDepthTexture;
58.             float _InvFade;
59.    
60.             fixed4 frag (v2f i) : SV_Target
61.             {
62.                 #ifdef SOFTPARTICLES_ON
63.                 float sceneZ = LinearEyeDepth (SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos)));
64.                 float partZ = i.projPos.z;
65.                 float fade = saturate (_InvFade * (sceneZ-partZ));
66.                 i.color.a *= fade;
67.                 #endif
68.        
69.                 half4 prev = i.color * tex2D(_MainTex, i.texcoord);
70.                 prev.rgb *= prev.a;
71.                 return prev;
72.             }
73.             ENDCG
74.         }
75.     }
76. }
77. }
78.  

I removed the "Fog" part, but now the textures look opaque even where they're transparent. They look overbright and there are artifacts.


What should I change to obtain the desired result?

I'd like them to seamlessly blend with the scenery. Maybe I should make them fade with distance? Could you please help me with the code? I'm using Exp2 scene Fog.
I also tried to make them fade with distance with this, but with no success:

Spoiler

Code (csharp):

1.  
2. Shader "NeatWolf/Additive (Soft) Fog" {
3. Properties {
4.     _MainTex ("Particle Texture", 2D) = "white" {}
5.     _InvFade ("Soft Particles Factor", Range(0.01,3.0)) = 1.0
6.     _MinVisDistance("Min Vis Distance", float) = 0.0
7.     _MaxVisDistance("Max Vis Distance", float) = 200.0
8. }
9.  
10. Category {
11.     Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" }
12.     Blend One OneMinusSrcColor
13.     ColorMask RGB
14.     Cull Off Lighting Off ZWrite Off Fog { Color (0,0,0,0) }
15.  
16.     SubShader {
17.         Pass {
18.        
19.             CGPROGRAM
20.             #pragma vertex vert
21.             #pragma fragment frag
22.             #pragma multi_compile_particles
23.  
24.             #include "UnityCG.cginc"
25.  
26.             sampler2D _MainTex;
27.             fixed4 _TintColor;
28.             half _MinVisDistance;
29.             half _MaxVisDistance;
30.             //struct appdata_t {
31.             //    float4 vertex : POSITION;
32.             //    fixed4 color : COLOR;
33.             //    float2 texcoord : TEXCOORD0;
34.             //};
35.  
36.             struct v2f {
37.                 float4 vertex : SV_POSITION;
38.                 fixed4 color : COLOR;
39.                 float2 texcoord : TEXCOORD0;
40.                 #ifdef SOFTPARTICLES_ON
41.                 float4 projPos : TEXCOORD1;
42.                 #endif
43.             };
44.  
45.             float4 _MainTex_ST;
46.            
47.             v2f vert (appdata_full v)
48.             {
49.                 v2f o;
50.                 o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
51.                 #ifdef SOFTPARTICLES_ON
52.                 o.projPos = ComputeScreenPos (o.vertex);
53.                 COMPUTE_EYEDEPTH(o.projPos.z);
54.                 #endif
55.                 o.color = v.color;
56.                 o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
57.                
58.                 //distance falloff
59.                 half3 viewDirW = _WorldSpaceCameraPos - mul((half4x4)_Object2World, v.vertex);
60.                 half viewDist = length(viewDirW);
61.                 half falloff = saturate((viewDist - _MinVisDistance) / (_MaxVisDistance - _MinVisDistance));
62.                 o.color.a *= (1.0f - falloff);
63.                
64.                 return o;
65.             }
66.  
67.             sampler2D_float _CameraDepthTexture;
68.             float _InvFade;
69.            
70.             fixed4 frag (v2f i) : SV_Target
71.             {
72.                 #ifdef SOFTPARTICLES_ON
73.                 float sceneZ = LinearEyeDepth (SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos)));
74.                 float partZ = i.projPos.z;
75.                 float fade = saturate (_InvFade * (sceneZ-partZ));
76.                 i.color.a *= fade;
77.                 #endif
78.                
79.                 half4 prev = i.color * tex2D(_MainTex, i.texcoord);
80.                 prev.rgb *= prev.a;
81.                 return prev;
82.             }
83.             ENDCG
84.         }
85.     }
86. }
87.  

Thank you for your time!

 

Your shader appears to be using

"Blend One OneMinusSrcColor"

Which seems a fairly odd blend mode? - and that explains why your alpha-fade has no effect, the blend mode doesn't use the source alpha.

If you can use a more standard additive blend mode - "Blend SrcAlpha One" - then your alpha-fade-with-distance approach should work well?