Example of Particle System GPU instancing in a Surface Shader
View an example script for applying GPU instancing to a Surface Shader.
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Here is a complete working example of Surface Shader using Particle System GPU Instancing:
Shader "Instanced/ParticleMeshesSurface" { Properties { _Color ("Color", Color) = (1,1,1,1) _MainTex ("Albedo (RGB)", 2D) = "white" {} _Glossiness ("Smoothness", Range(0,1)) = 0.5 _Metallic ("Metallic", Range(0,1)) = 0.0 } SubShader { Tags { "RenderType"="Opaque" } LOD 200 CGPROGRAM // Physically based Standard lighting model, and enable shadows on all light types // And generate the shadow pass with instancing support #pragma surface surf Standard nolightmap nometa noforwardadd keepalpha fullforwardshadows addshadow vertex:vert // Enable instancing for this shader #pragma multi_compile_instancing #pragma instancing_options procedural:vertInstancingSetup #pragma exclude_renderers gles #include "UnityStandardParticleInstancing.cginc" sampler2D _MainTex; struct Input { float2 uv_MainTex; fixed4 vertexColor; }; fixed4 _Color; half _Glossiness; half _Metallic; void vert (inout appdata_full v, out Input o) { UNITY_INITIALIZE_OUTPUT(Input, o); vertInstancingColor(o.vertexColor); vertInstancingUVs(v.texcoord, o.uv_MainTex); } void surf (Input IN, inout SurfaceOutputStandard o) { // Albedo comes from a texture tinted by color fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * IN.vertexColor * _Color; o.Albedo = c.rgb; // Metallic and smoothness come from slider variables o.Metallic = _Metallic; o.Smoothness = _Glossiness; o.Alpha = c.a; } ENDCG } FallBack "Diffuse"}
There are a number of small differences to a regular Surface Shader in the above example, which make it work with particle instancing.
Firstly, you must add the following two lines to enable Procedural Instancing, and specify the built-in vertex setup function. This function lives in UnityStandardParticleInstancing.cginc, and loads the per-instance (per-particle) positional data:
#pragma instancing_options procedural:vertInstancingSetup #include "UnityStandardParticleInstancing.cginc"
The other modification in the example is to the Vertex function, which has two extra lines that apply per-instance attributes, specifically, particle colors and Texture Sheet Animation texture coordinates:
vertInstancingColor(o.vertexColor); vertInstancingUVs(v.texcoord, o.uv_MainTex);