shader调试

简单点就是将要调试的值输出为颜色

1) 比如：调试顶点值时，将顶点值输出为颜色

Shader "My/VertexDebug"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
                fixed4 localPos : COLOR;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.localPos = v.vertex;
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                //fixed4 c = tex2D(_MainTex, i.uv);
                fixed4 c = fixed4(0, 0, 0, 1);
                c.xy = i.localPos.xy;
                return c;
            }
            ENDCG
        }
    }
}

效果图

2) 调试uv值时，将uv值输出为颜色

Shader "My/UVDebug"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 100

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 c = fixed4(0, 0, 0, 1);
                c.xy = i.uv;
                return c;
            }
            ENDCG
        }
    }
}

uv(0, 0)绘制在index0处，uv(1, 0)绘制在index1处, uv(1, 1)绘制在index3处, uv(0, 1)绘制在index2处

使用RenderDoc调试

1) 下载地址：RenderDoc

2) 安装完后，在Scene和Game视图都会有一个捕获当前画面的按钮

每次抓取后就可以开始调试了，双击抓取到的画面

切换到Pipeline State页签，在时间轴上拖动找到要调试的shader

切换到Mesh Viewer页签，就可以看到shader的变量信息了