Projector with surface shader?

Does anyone know of any examples of projecting textures in a Surface shader?
(Unity Projectors stylee)

All examples I am finding is from frag/vert shader examples and they are too different for me to figure out how to convert.

Cheers
Fred

 

I figured it out. The key was to realise that I could and how to combine surface and vertex shader functions.
I found that explained here, http://docs.unity3d.com/Manual/SL-SurfaceShaderExamples.html under 'Custom data computed per-vertex'.

This is my current and working shader for those who are interested,


Shader "Custom/fTestProj" {
Properties {
_Color ("MainColor", Color) = (1,1,1,1)
_MainTex ("Base (RGB)", 2D) = "white" {}
_AlphaTex ("Alpha (RGB)", 2D) = "white" {}
}
SubShader {
Tags {"Queue"="Transparent" "IgnoreProjector"="False" "RenderType"="Transparent"}
LOD 100
Blend SrcAlpha OneMinusSrcAlpha

CGPROGRAM
#pragma surface surf Lambert vertex:fProjUVs
#include "UnityCG.cginc"

float4 _Color;
sampler2D _MainTex;
sampler2D _AlphaTex;
uniform float4x4 _Projector;

struct Input {
float2 uv_MainTex;
float4 posProj : TEXCOORD0; // position in projector space
};

void fProjUVs (inout appdata_full v, out Input o) {
UNITY_INITIALIZE_OUTPUT(Input,o);
o.posProj = mul(_Projector, v.vertex);
}

void surf (Input IN, inout SurfaceOutput o) {

float4 projCol = tex2D(_MainTex , float2(IN.posProj) / IN.posProj.w) * _Color;
float projAlpha = tex2D(_AlphaTex , float2(IN.posProj) / IN.posProj.w);

o.Emission = projCol.rgb;
o.Alpha = projAlpha.r;
}
ENDCG
}
}
------------------------------------------------------------------------------------------------------------------------------

Sorry about the formatting. the code thing made it look weird too.

Cheers
Fred

 

Thanks Fred for sharing.. In Unity3D v5 and up there seems to be compile issues..
I solved it by adding .xy to the two lines that convert the float4 to a float2..

Code (CSharp):

1. float4 projCol = tex2D(_MainTex , float2(IN.posProj.xy) / IN.posProj.w) * _Color;
2. float projAlpha = tex2D(_AlphaTex , float2(IN.posProj.xy) / IN.posProj.w);