Unity shader学习之Alpha Blend

Unity shader学习之Alpha Blend

通过 ShaderLab 的 AlphaBlend 能够实现真正的半透明效果。

使用 AlphaBlend 时，需要关闭深度写入 ZWrite Off，但得非常小心物体的渲染顺序， RenderQueue。

转载请注明出处： http://www.cnblogs.com/jietian331/p/7158938.html

shader如下：

Shader "Custom/Alpha Blend"

{

    Properties

    {

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

        _Specular("Specular,", Color) = (,,,)

        _Gloss("Gloss", Range(,)) =

    }

    SubShader

    {

        Tags

        {

            "RenderType" = "Transparent"

            "Queue" = "Transparent"

            "IgnoreProjector" = "True"

        }

        Pass

        {

            Tags

            {

                "LightMode" = "ForwardBase"

            }

            ZWrite Off

            Blend SrcAlpha OneMinusSrcAlpha

            CGPROGRAM

            #pragma vertex vert

            #pragma fragment frag

            #include "UnityCG.cginc"

            #include "Lighting.cginc"

            sampler2D _MainTex;

            fixed4 _Specular;

            float _Gloss;

            struct appdata

            {

                float4 vertex : POSITION;

                fixed4 color : COLOR;

                float3 normal : NORMAL;

                float2 uv : TEXCOORD0;

            };

            struct v2f

            {

                float4 pos : SV_POSITION;

                fixed4 color : COLOR;

                float2 uv : TEXCOORD0;

                float3 worldNormal : TEXCOORD1;

                float3 worldLight : TEXCOORD2;

                float3 worldView : TEXCOORD3;

            };

            v2f vert(appdata v)

            {

                v2f o;

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

                o.color = v.color;

                o.uv = v.uv;

                o.worldNormal = normalize(UnityObjectToWorldNormal(v.normal));

                o.worldLight = normalize(WorldSpaceLightDir(v.vertex));

                o.worldView = normalize(WorldSpaceViewDir(v.vertex));

                return o;

            }

            fixed4 frag(v2f i) : SV_TARGET

            {

                fixed4 albedo = tex2D(_MainTex, i.uv) * i.color;

                fixed3 ambient = albedo.rgb * UNITY_LIGHTMODEL_AMBIENT.rgb;

                fixed3 diff = albedo.rgb * _LightColor0.rgb * max(, dot(i.worldNormal, i.worldLight));

                float3 halfDir = normalize(i.worldView + i.worldLight);

                fixed3 spec = albedo.rgb * _Specular.rgb * pow(max(, dot(halfDir, i.worldNormal)), _Gloss);

                fixed3 col = ambient + diff + spec;

                return fixed4(col, albedo.a);

            }

            ENDCG

        }

    }

    Fallback "Diffuse"

}

效果如下：

但关闭了深度写入之后，会引发一些问题，如：