unity shader片段與頂點着色光照漫反射

Shader "Custom/光照" {
	SubShader{
		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag			
			#include "unitycg.cginc"
			#include "lighting.cginc"

			
			struct v2f {
				float4 pos: POSITION;
				fixed4 color : COLOR;
				float3 normal:NORMAL;
			};
			v2f vert(appdata_base v)
			{
				v2f o;
				o.pos = UnityObjectToClipPos(v.vertex); //用最後矩陣*mvp矩陣
				o.color = float4(1, 0, 0, 1);
				o.normal = v.normal;
				//float c = dot(normalize(v.normal), normalize(_WorldSpaceLightPos0));
				//把法向量投射到世界座標，使用逆矩陣的轉置
				//float3 N = normalize(v.normal);
				//N = mul(N, unity_WorldToObject).xyz;
				//float c = dot(N, normalize(_WorldSpaceLightPos0));
				//c = saturate(c);
				//o.color = _LightColor0 /** c*/;
				return o;
			}

			fixed4 frag(in v2f IN) :COLOR
			{
				//待做
				float3 L = normalize(_WorldSpaceLightPos0).xyz;
				L = mul(unity_WorldToObject, L);
				float c = dot(IN.normal, L);
				c = saturate(c);
				IN.color = _LightColor0*c;
				return IN.color+UNITY_LIGHTMODEL_AMBIENT;
			}

			ENDCG
		}
	}
}