庄懂TA lesson3

半兰伯特

Shader "Shader/lanbert" {
    Properties{
    }
    SubShader{
        Tags {
            "RenderType" = "Opaque"
        }
        Pass {
            Name "FORWARD"
            Tags {
                "LightMode" = "ForwardBase"
            }


            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
            #pragma multi_compile_fwdbase_fullshadows
            #pragma target 3.0
            struct VertexInput {//输入
                float4 vertex : POSITION; //模型顶点信息
                float3 normal : NORMAL; //模型法线信息
            };
            struct VertexOutput {//顶点着色器输出
                float4 pos : SV_POSITION; //经过MVP矩阵转换到裁剪空间的顶点坐标
                float3 nDirWS:TEXCOORD0;//世界坐标法线方向向量
            };
            VertexOutput vert(VertexInput v) {
                VertexOutput o = (VertexOutput)0;
                o.pos = UnityObjectToClipPos(v.vertex);
                o.nDirWS=UnityObjectToWorldNormal(v.normal);
                return o;
            }
            float4 frag(VertexOutput i) : COLOR {
                float3 nDir = i.nDirWS;
                float3 lDir = normalize(_WorldSpaceLightPos0.xyz);//归一化
                float ndotl =dot(nDir,lDir)*0.5+0.5;//兰伯特法线和光向量点乘，转至（0，1）区间
                return float4(ndotl,ndotl,ndotl,1);
            }
                ENDCG
            }
    }
        FallBack "Diffuse"
}