Simple diffuse lighting shader example in the Built-In Render Pipeline
Example of a shader that uses simple diffuse lighting.
読み終わるまでの所要時間 2 分最終更新 23日前
A cat-like character lit using simple diffuse lighting, so surfaces facing away from the light are much darker.
The first thing we need to do is to indicate that our shader does in fact need lighting information passed to it. Unity's rendering pipeline supports various ways of rendering; here we'll be using the default forward rendering one.
We'll start by only supporting one directional light. Forward rendering in Unity works by rendering the main directional light, ambient, lightmaps and reflections in a single pass called ForwardBase. In the shader, this is indicated by adding a pass tag: Tags {"LightMode"="ForwardBase"}. This will make directional light data be passed into shader via some built-in variables.
Here's the shader that computes simple diffuse lighting per vertex, and uses a single main texture:
Shader "Lit/Simple Diffuse"{ Properties { [NoScaleOffset] _MainTex ("Texture", 2D) = "white" {} } SubShader { Pass { // indicate that our pass is the "base" pass in forward // rendering pipeline. It gets ambient and main directional // light data set up; light direction in _WorldSpaceLightPos0 // and color in _LightColor0 Tags {"LightMode"="ForwardBase"} HLSLPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" // for UnityObjectToWorldNormal #include "UnityLightingCommon.cginc" // for _LightColor0 struct v2f { float2 uv : TEXCOORD0; fixed4 diff : COLOR0; // diffuse lighting color float4 vertex : SV_POSITION; }; v2f vert (appdata_base v) { v2f o; o.vertex = UnityObjectToClipPos(v.vertex); o.uv = v.texcoord; // get vertex normal in world space half3 worldNormal = UnityObjectToWorldNormal(v.normal); // dot product between normal and light direction for // standard diffuse (Lambert) lighting half nl = max(0, dot(worldNormal, _WorldSpaceLightPos0.xyz)); // factor in the light color o.diff = nl * _LightColor0; return o; } sampler2D _MainTex; fixed4 frag (v2f i) : SV_Target { // sample texture fixed4 col = tex2D(_MainTex, i.uv); // multiply by lighting col *= i.diff; return col; } ENDHLSL } }}
This makes the object react to light direction - parts of it facing the light are illuminated, and parts facing away are not illuminated at all.