Shader Alpha/Transparency from LightReflection/Specular

Hi dear Devs,

Im trying to modify Shaders that works like the surface of water, but inverse in the case of lightReflections. But all my tries end up in a mess of Code without any results, with errors or 100% invisible materials.


If we take this ball for example, the shader should make it transparent where the light hits , based on the strength.
Where the light reflection is total white, the ball should be absolute invisible and only partly invisible around it.

It seemed easy, i take the o.Alpha = Specular and im done, but this didnt work out. The whole object was invisible.

Any Help is very welcome.

 

Specular data would not exist at that stage. Tho I can not confirm this particular feature will meet your needs, you might want to look into the Final Color Modifier. See the bottom of this page...http://docs.unity3d.com/Manual/SL-SurfaceShaderExamples.html

 

Hi, thanks for the reply,I just need this for confirmation;

It is not possible to make somthing like an inverted "specular only"-Shader ?

 

Code (CSharp):

1. Shader "Lighting Only"
2. {
3.      Properties
4.      {
5.          _Color ("Main Color", Color) = (1,1,1,1)
6.          _MainTex ("Base (RGB)", 2D) = "white" {}
7.      }
8.      SubShader
9.      {
10.          Blend SrcAlpha One
11.          ZWrite Off
12.          Tags
13.          {
14.              Queue = Transparent
15.          }
16.          ColorMask RGB
17.          CGPROGRAM
18.          #pragma surface surf MyLight alpha finalcolor:mycolor
19.          sampler2D _MainTex;
20.          fixed4 _Color;
21.          struct Input
22.          {
23.              float2 uv_MainTex;
24.          };
25.          void surf(Input IN, inout SurfaceOutput o)
26.          {
27.              fixed4 tex = tex2D(_MainTex, IN.uv_MainTex) * _Color;
28.              o.Albedo = tex.rgb;
29.              o.Alpha = tex.a;
30.          }
31.          float lightPower;
32.          fixed4 LightingMyLight(SurfaceOutput s, half3 lightDir, fixed atten)
33.          {
34.              lightPower = 1 - saturate(dot(normalize(s.Normal), lightDir));
35.              return fixed4((s.Albedo * _LightColor0.rgb) * (lightPower * atten * 2), 1);
36.          }
37.  
38.          void mycolor(Input IN, SurfaceOutput o, inout fixed4 color)
39.          {
40.              color.a = o.Alpha * lightPower;
41.          }
42.          ENDCG
43.      }
44.      Fallback "VertexLit", 2
45. }

I took This one from
http://answers.unity3d.com/questions/283985/a-shader-with-transparent-lit-area.html

It does not give me the same Result as in the picture for 3d objects but ok, i only use 2d planes anyway.
The bigger Problem is that i need black and not like in the link red. But when i change the color or a Texture map it turns alpha.


In the end is all i want some kind of Shader that behave like fog of war to any close light (becomes transparent)