Receiving shadows shader example in the Built-In Render Pipeline
Example of a shader that does shadow calculations.
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중요
The Built-In Render Pipeline is deprecated and will be made obsolete in a future release.
It remains supported, including bug fixes and maintenance, through the full Unity 6.7 LTS lifecycle.
For more information on migration, refer to Migrating from the Built-In Render Pipeline to the Universal Render Pipeline and Render pipeline feature comparison.
A cat-like character with accurate shadowing from the sun.
Implementing support for receiving shadows will require compiling the base lighting pass into several variants, to handle cases of "directional light without shadows" and "directional light with shadows" properly. # pragma multi_compile_fwdbase directive does this (see multiple shader variants for details). In fact it does a lot more: it also compiles variants for the different lightmap types, Enlighten Realtime Global Illumination being on or off etc. Currently we don't need all that, so we'll explicitly skip these variants.
Then to get actual shadowing computations, we'll # include "AutoLight.cginc" shader include file and use SHADOW_COORDS, TRANSFER_SHADOW, SHADOW_ATTENUATION macros from it.
Here's the shader:
Shader "Lit/Diffuse With Shadows"{ Properties { [NoScaleOffset] _MainTex ("Texture", 2D) = "white" {} } SubShader { Pass { Tags {"LightMode"="ForwardBase"} HLSLPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" #include "Lighting.cginc" // compile shader into multiple variants, with and without shadows // (we don't care about any lightmaps yet, so skip these variants) #pragma multi_compile_fwdbase nolightmap nodirlightmap nodynlightmap novertexlight // shadow helper functions and macros #include "AutoLight.cginc" struct v2f { float2 uv : TEXCOORD0; SHADOW_COORDS(1) // put shadows data into TEXCOORD1 half3 diff : COLOR0; half3 ambient : COLOR1; float4 pos : SV_POSITION; }; v2f vert (appdata_base v) { v2f o; o.pos = UnityObjectToClipPos(v.vertex); o.uv = v.texcoord; half3 worldNormal = UnityObjectToWorldNormal(v.normal); half nl = max(0, dot(worldNormal, _WorldSpaceLightPos0.xyz)); o.diff = nl * _LightColor0.rgb; o.ambient = ShadeSH9(half4(worldNormal,1)); // compute shadows data TRANSFER_SHADOW(o) return o; } sampler2D _MainTex; half4 frag (v2f i) : SV_Target { half4 col = tex2D(_MainTex, i.uv); // compute shadow attenuation (1.0 = fully lit, 0.0 = fully shadowed) half shadow = SHADOW_ATTENUATION(i); // darken light's illumination with shadow, keep ambient intact half3 lighting = i.diff * shadow + i.ambient; col.rgb *= lighting; return col; } ENDHLSL } // shadow casting support UsePass "Legacy Shaders/VertexLit/SHADOWCASTER" }}
Look, we have shadows now!