Feb
9
2012

Distance Blur Shader for Texture

Testing texture blurring in shader..using camera depth to determinate distance.

// DistanceBlurShader for Texture - not very useful.. - Unity version : mgear - http://unitycoder.com/blog
// Original shader: Field shaders by Google
/*
* Copyright 2009, Google Inc. All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*     * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
*     * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
*     * Neither the name of Google Inc. nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
Shader "mShaders/DistanceBlur1" {
Properties {
blurSizeX("BlurSizeX", Float) = 0
blurSizeY("BlurSizeY", Float) = 0
_MainTex ("Texture", 2D) = "white" { }

}
SubShader {
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
float blurSizeX;
float blurSizeY;
sampler2D _MainTex;
struct v2f {
float4  pos : SV_POSITION;
float2  uv : TEXCOORD0;
float2 depth : TEXCOORD1;
};
float4 _MainTex_ST;
v2f vert (appdata_base v)
{
v2f o;
o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
UNITY_TRANSFER_DEPTH(o.depth);
o.uv = TRANSFORM_TEX (v.texcoord, _MainTex);
return o;
}
half4 frag (v2f i) : COLOR
{
half4 sum = half4(0.0);
float depth = 1-i.depth.r*0.0005;
// gather pixel color from neighbours, distance to look for depends on camera distance..
sum += tex2D(_MainTex, float2(i.uv.x - 5.0 * depth, i.uv.y - 5.0 * depth)) * 0.025;
sum += tex2D(_MainTex, float2(i.uv.x - 4.0 * depth, i.uv.y - 4.0 * depth)) * 0.05;
sum += tex2D(_MainTex, float2(i.uv.x - 3.0 * depth, i.uv.y - 3.0 * depth)) * 0.09;
sum += tex2D(_MainTex, float2(i.uv.x - 2.0 * depth, i.uv.y - 2.0 * depth)) * 0.12;
sum += tex2D(_MainTex, float2(i.uv.x - 1.0 * depth, i.uv.y - 1.0 * depth)) * 0.15;
sum += tex2D(_MainTex, float2(i.uv.x, i.uv.y)) * 0.16;
sum += tex2D(_MainTex, float2(i.uv.x + 1.0 * depth, i.uv.y + 1.0 * depth)) * 0.15;
sum += tex2D(_MainTex, float2(i.uv.x + 2.0 * depth, i.uv.y + 2.0 * depth)) * 0.12;
sum += tex2D(_MainTex, float2(i.uv.x + 3.0 * depth, i.uv.y + 3.0 * depth)) * 0.09;
sum += tex2D(_MainTex, float2(i.uv.x + 4.0 * depth, i.uv.y + 4.0 * depth)) * 0.05;
sum += tex2D(_MainTex, float2(i.uv.x + 5.0 * depth, i.uv.y + 5.0 * depth)) * 0.025;
return sum;
}
ENDCG
}
}
Fallback "VertexLit"
} 

8 Comments + Add Comment

  • Hi,

    I am trying to learn something about shaders and this example is very nice, but I would like to understand, how would you remove the camera distance from the equation?

    Is it at all possible to make this work in unity 3.5 with just the horizontal and vertical bloom parameters, and without the camera?

    Thanks in advance.

    • “float depth = 1-i.depth.r*0.0005;” is the camera distance variable..

      Actually this shader has those “BlurSizeX” and “BlurSizeY” parameters already,
      so just replace all the the depth multipliers with those:
      //before
      sum += tex2D(_MainTex, float2(i.uv.x – 5.0 * depth, i.uv.y – 5.0 * depth)) * 0.025;
      ..
      //after
      sum += tex2D(_MainTex, float2(i.uv.x – 5.0 * BlurSizeX, i.uv.y – 5.0 * BlurSizeY)) * 0.025;
      ..

      maybe it works..?

  • Oh I see, thanks.
    Curiously in unity 3.5 i receive a warning about ‘exceeding the maximum number of 8 temporary registers’. Do you have an idea what this means?

  • I’m wondering: is it possible to add transparency to this shader? Thanks.

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