Resizing a projector and tiling texture?

Questions & Answers
1

I’ve made a projector for an underwater caustics effect but it only projects on a small portion of the map. It would not tile and if I took it out of orthographic view it would stretch the texture. Ideas?

2

Hey, try using this

Shader “Projector/Caustics” {

Properties {
   _Color ("Color", Color) = (1,1,1,0)
   _ShadowTex ("Cookie", 2D) = "black" { TexGen ObjectLinear }
   _Size ("Grid Size", Float) = 1
}

Subshader {
   Tags { "RenderType"="Transparent" "Queue"="Transparent+100" }
   Pass {
     ZWrite Off
     Offset -1, -1
     Fog { Mode Off }
     //ColorMask RGB
     //Blend SrcAlpha OneMinusSrcAlpha
     Blend DstColor One


     CGPROGRAM
     #pragma vertex vert
     #pragma fragment frag
     #pragma fragmentoption ARB_fog_exp2
     #pragma fragmentoption ARB_precision_hint_fastest
     #include "UnityCG.cginc"

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

     uniform sampler2D _ShadowTex;
     float4 _ShadowTex_ST;
     float4 _Color;
     float4x4 _Projector;
     fixed _Size;

     v2f vert (appdata_tan v) {
      v2f o;
      o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
      o.uv = TRANSFORM_TEX (mul (_Projector, v.vertex).xy, _ShadowTex);
      return o;
     }

     fixed4 frag (v2f i) : COLOR {
      if (i.uv.x < 1 && i.uv.y < 1)
          return tex2D (_ShadowTex, fmod (i.uv, 1 / _Size) * _Size) * _Color;
      else
          return fixed4 (0,0,0,0);
     }

     ENDCG
   }
}

}

I just modified it slightly from this script developed here on this thread: Projector + custom fragment shader = endless texture draw - Questions & Answers - Unity Discussions

It works fairly well for orthographic caustics.