[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"
[/code]

}
我修改

_MainTex ("Texture", 2D) = "white" {}
Tags { "RenderType" = "Opaque" }
[/code]

为

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

.

添加"alpha":

#pragma surface surf Lambert alpha
[/code]

.

在o.Albedo后添加如下...

o.Alpha = tex2D (_MainTex, IN.uv_MainTex).a;
[/code]

.
大功告成。