Graphics programming - Unity 3D shaders - 004.

In the previous tutorial number 002, I presented how a shader can be implemented using an HLSL type file that provides two output variables: _in1 and _in2. Theoretically, they should be renamed with _out because they are output. Today I will show you how to use the color variable as an input in the custom node. Here is the source code with a compound math function on a vector with size 4 for Color added in Shader Graph.

Let's see the source code :

#pragma shader_feature_local OutCode001

float DataInput_float( in float4  _in11, in float x , out float4 _out11)
{
    //_in11 = _input11Float;
    _in11 = _in11;
    _out11 = sin(_in11) * ( x * 1000 );
    return  _out11;
}

This is how to link the _in11, x and _out11 to Inputs and Outputs lists. You can see the function is used like DataInput and not DataInput_float in the GUI.

Graphics programming - Unity 3D shaders - 003.

This is a new default example like the one from the previous tutorial, it is a little more complex, but you can see the differences.

I commented the default source code generated by Unity 3D and added a default source code for coloring with RGB color range.

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

//Shader "Custom/CG_RGB"
//{
//    Properties
//    {
//        _Color ("Color", Color) = (1,1,1,1)
//        _MainTex ("Albedo (RGB)", 2D) = "white" {}
//        _Glossiness ("Smoothness", Range(0,1)) = 0.5
//        _Metallic ("Metallic", Range(0,1)) = 0.0
//    }
//    SubShader
//    {
//        Tags { "RenderType"="Opaque" }
//        LOD 200

//        CGPROGRAM
//        // Physically based Standard lighting model, and enable shadows on all light types
//        #pragma surface surf Standard fullforwardshadows

//        // Use shader model 3.0 target, to get nicer looking lighting
//        #pragma target 3.0

//        sampler2D _MainTex;

//        struct Input
//        {
//            float2 uv_MainTex;
//        };

//        half _Glossiness;
//        half _Metallic;
//        fixed4 _Color;

//        // Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
//        // See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
//        // #pragma instancing_options assumeuniformscaling
//        UNITY_INSTANCING_BUFFER_START(Props)
//            // put more per-instance properties here
//        UNITY_INSTANCING_BUFFER_END(Props)

//        void surf (Input IN, inout SurfaceOutputStandard o)
//        {
//            // Albedo comes from a texture tinted by color
//            fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
//            o.Albedo = c.rgb;
//            // Metallic and smoothness come from slider variables
//            o.Metallic = _Metallic;
//            o.Smoothness = _Glossiness;
//            o.Alpha = c.a;
//        }
//        ENDCG
//    }
//    FallBack "Diffuse"
//}
Shader "Cg shader for RGB cube" { 
   SubShader { 
      Pass { 
         CGPROGRAM 
 
         #pragma vertex vert // vert function is the vertex shader 
         #pragma fragment frag // frag function is the fragment shader
 
         void vert(float4 vertexPos : POSITION,
            out float4 pos : SV_POSITION,
            out float4 col : TEXCOORD0)  
         {
            pos =  UnityObjectToClipPos(vertexPos);
            col = vertexPos + float4(0.5, 0.5, 0.5, 0.0);
            return;
         }
 
         float4 frag(float4 pos : SV_POSITION, 
            float4 col : TEXCOORD0) : COLOR 
         {
            return col; 
         }
 
         ENDCG 
      }
   }
}

Here is the result attached to the same material from the previous tutorial, but with this default shader.