HSV Shader with Alpha

Questions & Answers
1

Hi there,
Can some of you Shader Coding Ninja’s please help me with my problem. I have been looking around and just can’t figure it out by myself.
Basically i want to add a Alpha property to the shader below which is a HSV Shader which i found in the forums.
Many thanks in advance to you Ninja’s out there.

Shader "Custom/HSVShader" {

    Properties {

        _MainTex ("Texture", 2D) = "white" {}

        _HueShift("HueShift", Float ) = 0

        _Sat("Saturation", Float) = 1

        _Val("Value", Float) = 1

    }

    SubShader {

 

        Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType" = "Transparent" }

        ZWrite Off

        Blend SrcAlpha OneMinusSrcAlpha

        Cull Off

 

        Pass

        {

            CGPROGRAM

            #pragma vertex vert

            #pragma fragment frag

            #pragma target 2.0

 

            #include "UnityCG.cginc"

 

            float3 shift_col(float3 RGB, float3 shift)

            {

            float3 RESULT = float3(RGB);

            float VSU = shift.z*shift.y*cos(shift.x*3.14159265/180);

                float VSW = shift.z*shift.y*sin(shift.x*3.14159265/180);

                

                RESULT.x = (.299*shift.z+.701*VSU+.168*VSW)*RGB.x

                        + (.587*shift.z-.587*VSU+.330*VSW)*RGB.y

                        + (.114*shift.z-.114*VSU-.497*VSW)*RGB.z;

                

                RESULT.y = (.299*shift.z-.299*VSU-.328*VSW)*RGB.x

                        + (.587*shift.z+.413*VSU+.035*VSW)*RGB.y

                        + (.114*shift.z-.114*VSU+.292*VSW)*RGB.z;

                

                RESULT.z = (.299*shift.z-.3*VSU+1.25*VSW)*RGB.x

                        + (.587*shift.z-.588*VSU-1.05*VSW)*RGB.y

                        + (.114*shift.z+.886*VSU-.203*VSW)*RGB.z;

                

            return (RESULT);

            }

 

            struct v2f {

                float4  pos : SV_POSITION;

                float2  uv : TEXCOORD0;

            };

 

            float4 _MainTex_ST;

 

            v2f vert (appdata_base v)

            {

                v2f o;

                o.pos = mul (UNITY_MATRIX_MVP, v.vertex);

                o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);

                return o;

            }

 

            sampler2D _MainTex;

            float _HueShift;

            float _Sat;

            float _Val;

 

            half4 frag(v2f i) : COLOR

            {

                half4 col = tex2D(_MainTex, i.uv);

                float3 shift = float3(_HueShift, _Sat, _Val);

                

                return half4( half3(shift_col(col, shift)), col.a);

            }

            ENDCG

        }

    }

    Fallback "Particles/Alpha Blended"

}
2

Hi,

you need to make a new properties line called alpha at top,
then after include line write:

float alpha;

and replace col.a at the end with word alpha

this is a better hsv fct btwm, sane thing hsb

float3 Hue(float H)
{
half R = abs(H * 6 - 3) - 1;
half G = 2 - abs(H * 6 - 2);
half B = 2 - abs(H * 6 - 4);
return saturate(half3(R,G,B));
}
half4 HSVtoRGB(in half3 HSV)
{
return half4(((Hue(HSV.x) - 1) * HSV.y + 1) * HSV.z,1);
}

3

Here is my Final Shader. I got help in the Unity forums:

Shader "Custom/HSVShader" {

    Properties {

        _MainTex ("Texture", 2D) = "white" {}

        _HueShift("HueShift", Float ) = 0

        _Sat("Saturation", Float) = 1

        _Val("Value", Float) = 1
        
        _Alpha ("Alpha", Range(0,1)) = 1

    }

    SubShader {

 

        Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType" = "Transparent" }

        ZWrite Off

        Blend SrcAlpha OneMinusSrcAlpha

        Cull Off

 

        Pass

        {

            CGPROGRAM

            #pragma vertex vert

            #pragma fragment frag

            #pragma target 2.0

 

            #include "UnityCG.cginc"

 			float _Alpha;

            float3 shift_col(float3 RGB, float3 shift)

            {

            float3 RESULT = float3(RGB);

            float VSU = shift.z*shift.y*cos(shift.x*3.14159265/180);

                float VSW = shift.z*shift.y*sin(shift.x*3.14159265/180);

                

                RESULT.x = (.299*shift.z+.701*VSU+.168*VSW)*RGB.x

                        + (.587*shift.z-.587*VSU+.330*VSW)*RGB.y

                        + (.114*shift.z-.114*VSU-.497*VSW)*RGB.z;

                

                RESULT.y = (.299*shift.z-.299*VSU-.328*VSW)*RGB.x

                        + (.587*shift.z+.413*VSU+.035*VSW)*RGB.y

                        + (.114*shift.z-.114*VSU+.292*VSW)*RGB.z;

                

                RESULT.z = (.299*shift.z-.3*VSU+1.25*VSW)*RGB.x

                        + (.587*shift.z-.588*VSU-1.05*VSW)*RGB.y

                        + (.114*shift.z+.886*VSU-.203*VSW)*RGB.z;

                

            return (RESULT);

            }

 

            struct v2f {

                float4  pos : SV_POSITION;

                float2  uv : TEXCOORD0;

            };

 

            float4 _MainTex_ST;

 

            v2f vert (appdata_base v)

            {

                v2f o;

                o.pos = mul (UNITY_MATRIX_MVP, v.vertex);

                o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);

                return o;

            }

 

            sampler2D _MainTex;

            float _HueShift;

            float _Sat;

            float _Val;

 

            half4 frag(v2f i) : COLOR

            {

                half4 col = tex2D(_MainTex, i.uv);

                float3 shift = float3(_HueShift, _Sat, _Val);

                
				return half4( half3(shift_col(col, shift)), col.a * _Alpha);
                

            }

            ENDCG

        }

    }

    Fallback "Particles/Alpha Blended"

}