Radial Blur Shader

An article by mgear    3 Comments

Using the same godrays shader, you get nice radial blur effect for images. This one is also modified to use objectUV, instead of screenUV,
so you can rotate the plane around..

Webplayer:
http://unitycoder.com/upload/demos/Radial_Blur_shader_unity/ *webplayer broken in current unity webplayer version?

Shader source:

// FakeRadialBlur shader for Unity (v1.0)
// based on this shader: http://unitycoder.com/blog/2012/10/02/fake-godrays-shader/
// which is converted/based on this webgl shader: http://demo.bkcore.com/threejs/webgl_tron_godrays.html

Shader "UnityCoder/FakeRadialBlur"
{
Properties
{
tDiffuse ("Base (RGB)", 2D) = "white" {}
fX ("fX", Float) = 0.5
fY ("fY", Float) = 0.5
fExposure ("fExposure", Float) = 0.6
fDecay ("fDecay", Float) = 0.93
fDensity ("fDensity", Float) = 0.96
fWeight ("fWeight", Float) = 0.4
fClamp ("fClamp", Float) = 1.0
//iSamples ("iSamples", Int) = 20
}
SubShader {
Tags { "RenderType"="Opaque" }
LOD 200
Cull Off

CGPROGRAM
#pragma target 3.0
#pragma surface surf Lambert

sampler2D tDiffuse;
float fX,fY,fExposure,fDecay,fDensity,fWeight,fClamp,iSamples;

struct Input {
float2 uvtDiffuse;
float4 screenPos;
};

void surf (Input IN, inout SurfaceOutput o)
{
int iSamples=100;
float2 vUv = IN.uvtDiffuse;
//vUv *= float2(1,1); // repeat?
float2 deltaTextCoord = float2(vUv - float2(fX,fY));
deltaTextCoord *= 1.0 /  float(iSamples) * fDensity;
float2 coord = vUv;
float illuminationDecay = 1.0;
float4 FragColor = float4(0.0);
for(int i=0; i < iSamples ; i++)
{
coord -= deltaTextCoord;
float4 texel = tex2D(tDiffuse, coord);
texel *= illuminationDecay * fWeight;
FragColor += texel;
illuminationDecay *= fDecay;
}
FragColor *= fExposure;
FragColor = clamp(FragColor, 0.0, fClamp);
float4 c = FragColor;
o.Albedo = c.rgb;
o.Alpha = c.a;

}
ENDCG
}
FallBack "Diffuse"
}