Contrast and hue using CG in Unity

Unity Engine
1

Dears CG developer,

I’m looking for how I could how to adjust contrast or hue of 3D object using CG ?

Thx for any help :slight_smile:

2

I did contrast image effect in cg before,
in cg’s pixel shader,
adjust contrast:

//custom data
//you can control this in C#
//SetFloat(“contrastIntensity”, contrastIntensity);
uniform float contrastIntensity;

float4 frag (v2f_img i) : COLOR
{
float4 temp = tex2D(_MainTex,i.uv);
temp = (temp-0.5)*contrastIntensity + 0.5;

return temp;
}

//when contrastIntensity = 1, the result is normal
//when contrastIntensity < 1, the result is less contrast
//when contrastIntensity > 1, the result is more contrast

3

Thank you!
Did u worked on the noise, distortion or chromatic aberrations of the texture? that would be much inetresting for me. Thank you again for your help : ))

4

chromatic aberrations =

Shader "C4Cat/Image Effects/Chromatic Aberration" {
Properties {
    _MainTex ("Base (RGB)", RECT) = "white" {}
}
SubShader {
    Pass {
        ZTest Always Cull Off ZWrite Off
        Fog { Mode off }
CGPROGRAM
#pragma vertex vert_img
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
// frag shaders data
uniform sampler2D _MainTex;

//custom data
uniform float chromaticAberrationIntensity;
uniform float vignetteStrength;
// frag shader
float4 frag (v2f_img i) : COLOR
{
    float uvOffsetModify = (abs(i.uv.y-0.5) * abs(i.uv.x-0.5));
    //float uvOffsetModify = abs(i.uv.y-0.5);           
    float2 uvOffset = float2(chromaticAberrationIntensity,0);
    uvOffset *= uvOffsetModify;
   
    //shift R to left a bit
    float2 uvR = i.uv - uvOffset;
    float4 temp = tex2D(_MainTex, uvR);
    float R = temp.r;
   
    //keep B in original position
    temp = tex2D(_MainTex, i.uv);
    float B = temp.b;
   
    //shift G to right a bit
    float2 uvG = i.uv + uvOffset;
    temp = tex2D(_MainTex, uvG);
    float G = temp.g;
   
    //combine R G B result
    float4 result = float4(R,G,B,1);
   
    result *= 1 - uvOffsetModify * vignetteStrength;
   
   
    return result;
}
ENDCG
    }
}
Fallback off
}

sample R a bit left,
sample G a bit right,
sample B as usually,
combine RGB for output.

5

distortion =
sample pixel color with offset UV,
how each pixel offset when sampling texture is base on your need.

noise, what kind of noise you need?

Are you doing something like a TV shader?

6

In my case it’s exactly to copy noise from a texture(I dunno how to do it) and put it my 3D object via the shader.

7

can a simple multiply works for you?
mainTex * noise