ThermalVisionImageEffect.shader

Shader "Hidden/ThermalVisionImageEffect"
{
    Properties
    {
        _Matcap("Texture", 2D) = "white" {}
        [HideInInspector]_MainTex("Texture", 2D) = "white"{}
        _Opacity("Normals Opacity", Range(0,2)) = 0.4

    }
    SubShader
    {
        // No culling or depth
        Cull Off ZWrite Off ZTest Always
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
                float4 pos : TEXCOORD1;
            };

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;
                o.pos = v.vertex;
                return o;
            }
            float _Opacity;
            sampler2D _CameraDepthNormalsTexture;

            float4 GetPixelValue(in float2 uv) {
                half3 normal;
                float depth;
                DecodeDepthNormal(tex2D(_CameraDepthNormalsTexture, uv), depth, normal);

                return fixed4(normal, depth);
            }

            sampler2D _Matcap, _MainTex;

            fixed4 frag (v2f i) : SV_Target
            {

            fixed4 normals = GetPixelValue(i.uv);
            fixed4 color = tex2D(_MainTex, i.uv );
            float2 cap = normals.xy * 0.5 + 0.5;
            fixed4 col = tex2D(_Matcap, cap * _Opacity);
            return color + col;
            }
            ENDCG
        }
    }
}