[unity 基础教程]给着色器shader添加透明属性

我有个shader文件。内容如下

Shader "HSB_HSV_Colorpicker" {
 
Properties {
 
  _MainTex ("Texture", 2D) = "white" {}
  _HueShift("HueShift", Float) = 0
}
 
SubShader {
 
  Tags { "RenderType" = "Opaque" }
 
  CGPROGRAM
 
  #pragma surface surf Lambert
  #pragma target 3.0
 
 
    float3 rgb_to_hsv_no_clip(float3 RGB)
 
    {
 
            float3 HSV;
 
 
     float minChannel, maxChannel;
 
     if (RGB.x > RGB.y) {
 
      maxChannel = RGB.x;
      minChannel = RGB.y;
 
     }
 
     else {
 
      maxChannel = RGB.y;
      minChannel = RGB.x;
 
     }
 
 
 
     if (RGB.z > maxChannel) maxChannel = RGB.z;
 
     if (RGB.z < minChannel) minChannel = RGB.z;
 
 
            HSV.xy = 0;
 
            HSV.z = maxChannel;
 
            float delta = maxChannel - minChannel;             //Delta RGB value
 
            if (delta != 0) {                    // If gray, leave H & S at zero
 
               HSV.y = delta / HSV.z;
 
               float3 delRGB;
 
               delRGB = (HSV.zzz - RGB + 3*delta) / (6.0*delta);
 
               if      ( RGB.x == HSV.z ) HSV.x = delRGB.z - delRGB.y;
 
               else if ( RGB.y == HSV.z ) HSV.x = ( 1.0/3.0) + delRGB.x - delRGB.z;
 
               else if ( RGB.z == HSV.z ) HSV.x = ( 2.0/3.0) + delRGB.y - delRGB.x;
 
            }
 
            return (HSV);
 
    }
 
 
 
    float3 hsv_to_rgb(float3 HSV)
    {
 
            float3 RGB = HSV.z;
 
 
 
               float var_h = HSV.x * 6;
 
               float var_i = floor(var_h);   // Or ... var_i = floor( var_h )
 
               float var_1 = HSV.z * (1.0 - HSV.y);
 
               float var_2 = HSV.z * (1.0 - HSV.y * (var_h-var_i));
 
               float var_3 = HSV.z * (1.0 - HSV.y * (1-(var_h-var_i)));
 
               if      (var_i == 0) { RGB = float3(HSV.z, var_3, var_1); }
 
               else if (var_i == 1) { RGB = float3(var_2, HSV.z, var_1); }
 
               else if (var_i == 2) { RGB = float3(var_1, HSV.z, var_3); }
 
               else if (var_i == 3) { RGB = float3(var_1, var_2, HSV.z); }
 
               else if (var_i == 4) { RGB = float3(var_3, var_1, HSV.z); }
 
               else                 { RGB = float3(HSV.z, var_1, var_2); }
 
 
 
       return (RGB);
 
    }
 
 
 
  struct Input {
 
      float2 uv_MainTex;
 
  };
 
 
 
  sampler2D _MainTex;
 
  float _HueShift;
 
 
 
  void surf (Input IN, inout SurfaceOutput o) {
 
      o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb;
 
 
      float3 hsv = rgb_to_hsv_no_clip(o.Albedo.xyz);
 
      hsv.x+=_HueShift;
 
 
      if ( hsv.x > 1.0 ) { hsv.x -= 1.0; }
 
      o.Albedo = half3(hsv_to_rgb(hsv));
 
 
 
  }
 
 
 
  ENDCG
 
}
 
Fallback "Diffuse"

}

我修改

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

为

_MainTex ("Color (RGB) Alpha (A)", 2D) = "white"
Tags { "Queue"="Transparent" "RenderType"="Transparent" }

.

添加"alpha":

#pragma surface surf Lambert alpha

.

在o.Albedo后添加如下...

o.Alpha = tex2D (_MainTex, IN.uv_MainTex).a;

.

大功告成。