Unity Shader 纹理映射的实现

 1 // 纹理映射的编写
 2 Shader "TMoon/04-Texture" {
 3     Properties{
 4         _Color("Color",Color) = (1,1,1,1)
 5         _MainTex("Main Tex",2D) = "white"{}
 6     }
 7
 8     SubShader{
 9
10         Pass{
11
12             Tags {"LightMode" = "ForwardBase"}
13
14             CGPROGRAM
15
16             #include "Lighting.cginc"
17
18             #pragma vertex vert
19             #pragma fragment frag
20
21             fixed4 _Color;
22             sampler2D _MainTex;
23             float4 _MainTex_ST; //命名必须根据_MainTex 这里自动匹配面板的Tiling和Offset
24
25             // application to vertex
26             // 由应用程序传递给顶点函数
27             struct a2v {
28                 float4 vertex:POSITION;
29                 float3 normal:NORMAL;
30                 float4 texcoord:TEXCOORD0; // 模型的纹理坐标
31             };
32
33             // vertex to fragment
34             // 由顶点函数传递给片元函数
35             struct v2f {
36                 float4 svPos:SV_POSITION;
37                 float3 worldNormal:TEXCOORD0;
38                 float4 worldVertex:TEXCOORD1;
39                 float2 uv:TEXCOORD2;
40             };
41
42             v2f vert(a2v v) {
43                 v2f f;
44
45                 f.svPos = mul(UNITY_MATRIX_MVP, v.vertex);
46                 f.worldNormal = normalize(UnityObjectToWorldNormal(v.normal));
47                 // 将模型空间的顶点坐标变换到世界空间上
48                 f.worldVertex = mul(v.vertex, unity_WorldToObject);
49                 // 将纹理坐标赋值给v2f.uv并赋值面板贴图的旋转缩放
50                 f.uv = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;
51
52                 return f;
53             }
54
55             float4 frag(v2f f) : SV_Target{
56
57                 fixed3 lightDir = normalize(WorldSpaceLightDir(f.worldVertex));
58
59                 // tex2D 根据贴图获取模型纹理坐标身上对应的像素点颜色值
60                 fixed3 texColor = tex2D(_MainTex,f.uv.xy) * _Color.rgb;
61
62                 // 为漫反射混合上每个像素点的纹理颜色
63                 fixed3 diffuse = _LightColor0.rgb * texColor * max(dot(f.worldNormal, lightDir), 0);
64
65                 return fixed4(diffuse,1);
66             }
67
68             ENDCG
69         }
70     }
71
72     Fallback "VertexLit"
73 }