Replacement Shaders and Projectors

Hey everyone,

I am trying to render only the Projectors of my scene but I can't, all I have is a black image and it seems logical as Projectors need other objects to be projected on.
For this I am using replaced shaders but it doesn't work and to be honest, I don't have any idea on how to render only my projectors of my scene... Is there a way to do that ?

Thanks a lot !

 

Even with Unity 5 and the framedebugger, I can't retrieve the projector pass, it's always combined with other objects. It doesn't seem that it's possible but maybe I am wrong. Any idea @Aras ?

 

Thank you @Aras, I'll try to improve my question

The aim is to use a post process effect on some projectors with a specific shader.
For that I would like to exclude any other object from the camera and render only some specified projectors inside a rendertexture.
First, I am using a disabled camera with a script and a target rendertexture. In that rendertexture I only want to retrieve the MainTex of some projectors with a black background.

Code (CSharp):

1. // Done OnPreCull
2. RenderWithShader(myShader, ",myReplacementTag");

The shader on my projectors has myReplacementTag.

Here is myShader used for the post process effect.

Code (CSharp):

1. Shader "Custom/Projector"
2. {
3.     Properties
4.     {
5.         _MainTex ("Diffuse (RGBA)", 2D) = "white" {}
6.     }
7.     SubShader
8.     {
9.         Tags { "myReplacementTag"="anything" }
10.         Pass
11.         {
12.             Blend SrcAlpha OneMinusSrcAlpha
13.             ZWrite Off
14.             Offset -1, -1
15.             CGPROGRAM
16.             #pragma vertex vert
17.             #pragma fragment frag
18.              sampler2D            _MainTex;
19.              uniform float4x4    _Projector;
20.               struct vertexInput
21.               {
22.                 float4 vertex : POSITION;
23.                 float3 normal : NORMAL;
24.              };
25.              struct vertexOutput
26.              {
27.                 float4 pos : SV_POSITION;
28.                 float4 posProj : TEXCOORD0;
29.              };
30.  
31.              vertexOutput vert(vertexInput input)
32.              {
33.                 vertexOutput output;
34.                 output.posProj = mul(_Projector, input.vertex);
35.                 output.pos = mul(UNITY_MATRIX_MVP, input.vertex);
36.                 return output;
37.              }
38.  
39.              float4 frag(vertexOutput input) : COLOR
40.              {
41.                  if (input.posProj.w > 0.0)
42.                 { return tex2D(_MainTex, input.posProj.xy / input.posProj.w); }
43.                 else
44.                 { return float4(0.0, 0.0, 0.0, 0.0); }
45.              }
46.              ENDCG
47.          }
48.    }
49.     Fallback Off
50. }

After that I want to send my rendertexture to the specified projector and apply it but this should not be a problem except maybe for the projection.

For the moment, I have a simple setup scene with two projectors and a plane and my rendertexture is all black.
The first thing would be to fill the rendertexture with black and the specified projectors with their MainTex colors. But I don't know what I am doing wrong...and I don't know if what I want to do is possible.

Tell me if you need more informations.

 

@Aras I take the liberty to remember you my question, I would like to know if you have an idea if there is an issue or if it's not possible.
Of course, any other idea is also welcome !

Thank you !

 

Any idea ?

 

I only know is in Unity5.6.4, Unity Don't support projectors when doing shader replacement. I found it in the unity source code.