| 网格 | 要绘制的网格。 |
| 子网格索引 | 要绘制的网格的子集。这仅适用于由多种材质组成的网格。 |
| 材质 | 要使用的材质。 |
| 范围 | 你打算绘制的实例周围的边界体积。 |
| bufferWithArgs | 包含如何绘制该网格的实例数量的参数的 GPU 缓冲区。 |
| argsOffset | 绘制参数开始处的缓冲区中的字节偏移量。 |
| properties | 要应用的附加材料属性。参见MaterialPropertyBlock。 |
| castShadows | 确定网格能否投射阴影。 |
| receiveShadows | 确定网格能否接收阴影。 |
| layer | 要使用的图层。 |
| camera | 如果为null（默认值），网格将在所有摄像机中绘制。否则，它将仅在给定的摄像机中绘制。 |
| lightProbeUsage | 实例的LightProbeUsage。 |
此函数现已弃用。请改用Graphics.RenderMeshIndirect。使用 GPU 实例化多次绘制同一网格。
此函数仅适用于支持计算着色器的平台。
类似于Graphics.DrawMeshInstanced，此函数绘制同一网格的多个实例，但与该方法不同，有关要绘制多少个实例的参数来自bufferWithArgs。
在你要使用实例化着色器绘制特定次数的同一网格时，请使用此函数。网格不会被视景体或烘焙的遮挡器进一步剔除，也不会针对透明度或 z 效率进行排序。
带参数缓冲区bufferWithArgs必须在给定的argsOffset偏移量处有五个整数：每个实例的索引计数、实例计数、起始索引位置、基本顶点位置、起始实例位置。
如果网格内的子网格具有不同的拓扑（例如三角形和线），Unity 才需要 submeshIndex 参数。否则，有关要绘制哪个子网格的所有信息都来自 bufferWithArgs 参数。
以下脚本可用于绘制同一网格的多个实例
using UnityEngine; using System.Collections;
public class ExampleClass : MonoBehaviour { public int instanceCount = 100000; public Mesh instanceMesh; public Material instanceMaterial; public int subMeshIndex = 0;
private int cachedInstanceCount = -1; private int cachedSubMeshIndex = -1; private ComputeBuffer positionBuffer; private ComputeBuffer argsBuffer; private uint[] args = new uint[5] { 0, 0, 0, 0, 0 };
void Start() { argsBuffer = new ComputeBuffer(1, args.Length * sizeof(uint), ComputeBufferType.IndirectArguments); UpdateBuffers(); }
void Update() { // Update starting position buffer if (cachedInstanceCount != instanceCount || cachedSubMeshIndex != subMeshIndex) UpdateBuffers();
// Pad input if (Input.GetAxisRaw("Horizontal") != 0.0f) instanceCount = (int)Mathf.Clamp(instanceCount + Input.GetAxis("Horizontal") * 40000, 1.0f, 5000000.0f);
// Render Graphics.DrawMeshInstancedIndirect(instanceMesh, subMeshIndex, instanceMaterial, new Bounds(Vector3.zero, new Vector3(100.0f, 100.0f, 100.0f)), argsBuffer); }
void OnGUI() { GUI.Label(new Rect(265, 25, 200, 30), "Instance Count: " + instanceCount.ToString()); instanceCount = (int)GUI.HorizontalSlider(new Rect(25, 20, 200, 30), (float)instanceCount, 1.0f, 5000000.0f); }
void UpdateBuffers() { // Ensure submesh index is in range if (instanceMesh != null) subMeshIndex = Mathf.Clamp(subMeshIndex, 0, instanceMesh.subMeshCount - 1);
// Positions if (positionBuffer != null) positionBuffer.Release(); positionBuffer = new ComputeBuffer(instanceCount, 16); Vector4[] positions = new Vector4[instanceCount]; for (int i = 0; i < instanceCount; i++) { float angle = Random.Range(0.0f, Mathf.PI * 2.0f); float distance = Random.Range(20.0f, 100.0f); float height = Random.Range(-2.0f, 2.0f); float size = Random.Range(0.05f, 0.25f); positions[i] = new Vector4(Mathf.Sin(angle) * distance, height, Mathf.Cos(angle) * distance, size); } positionBuffer.SetData(positions); instanceMaterial.SetBuffer("positionBuffer", positionBuffer);
// Indirect args if (instanceMesh != null) { args[0] = (uint)instanceMesh.GetIndexCount(subMeshIndex); args[1] = (uint)instanceCount; args[2] = (uint)instanceMesh.GetIndexStart(subMeshIndex); args[3] = (uint)instanceMesh.GetBaseVertex(subMeshIndex); } else { args[0] = args[1] = args[2] = args[3] = 0; } argsBuffer.SetData(args);
cachedInstanceCount = instanceCount; cachedSubMeshIndex = subMeshIndex; }
void OnDisable() { if (positionBuffer != null) positionBuffer.Release(); positionBuffer = null;
if (argsBuffer != null) argsBuffer.Release(); argsBuffer = null; } }
以下曲面着色器可用于与上述示例脚本结合使用
Shader "Instanced/InstancedSurfaceShader" { Properties { _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 #pragma surface surf Standard addshadow fullforwardshadows #pragma multi_compile_instancing #pragma instancing_options procedural:setup
sampler2D _MainTex;
struct Input { float2 uv_MainTex; };
#ifdef UNITY_PROCEDURAL_INSTANCING_ENABLED StructuredBuffer<float4> positionBuffer; #endif
void rotate2D(inout float2 v, float r) { float s, c; sincos(r, s, c); v = float2(v.x * c - v.y * s, v.x * s + v.y * c); }
void setup() { #ifdef UNITY_PROCEDURAL_INSTANCING_ENABLED float4 data = positionBuffer[unity_InstanceID];
float rotation = data.w * data.w * _Time.y * 0.5f; rotate2D(data.xz, rotation);
unity_ObjectToWorld._11_21_31_41 = float4(data.w, 0, 0, 0); unity_ObjectToWorld._12_22_32_42 = float4(0, data.w, 0, 0); unity_ObjectToWorld._13_23_33_43 = float4(0, 0, data.w, 0); unity_ObjectToWorld._14_24_34_44 = float4(data.xyz, 1); unity_WorldToObject = unity_ObjectToWorld; unity_WorldToObject._14_24_34 *= -1; unity_WorldToObject._11_22_33 = 1.0f / unity_WorldToObject._11_22_33; #endif }
half _Glossiness; half _Metallic;
void surf (Input IN, inout SurfaceOutputStandard o) { fixed4 c = tex2D (_MainTex, IN.uv_MainTex); o.Albedo = c.rgb; o.Metallic = _Metallic; o.Smoothness = _Glossiness; o.Alpha = c.a; } ENDCG } FallBack "Diffuse" }
以下定制着色器可用于与上述示例脚本结合使用
Shader "Instanced/InstancedShader" { Properties { _MainTex ("Albedo (RGB)", 2D) = "white" {} } SubShader {
Pass {
Tags {"LightMode"="ForwardBase"}
CGPROGRAM
#pragma vertex vert #pragma fragment frag #pragma multi_compile_fwdbase nolightmap nodirlightmap nodynlightmap novertexlight #pragma target 4.5
#include "UnityCG.cginc" #include "UnityLightingCommon.cginc" #include "AutoLight.cginc"
sampler2D _MainTex;
#if SHADER_TARGET >= 45 StructuredBuffer<float4> positionBuffer; #endif
struct v2f { float4 pos : SV_POSITION; float2 uv_MainTex : TEXCOORD0; float3 ambient : TEXCOORD1; float3 diffuse : TEXCOORD2; float3 color : TEXCOORD3; SHADOW_COORDS(4) };
void rotate2D(inout float2 v, float r) { float s, c; sincos(r, s, c); v = float2(v.x * c - v.y * s, v.x * s + v.y * c); }
v2f vert (appdata_full v, uint instanceID : SV_InstanceID) { #if SHADER_TARGET >= 45 float4 data = positionBuffer[instanceID]; #else float4 data = 0; #endif
float rotation = data.w * data.w * _Time.x * 0.5f; rotate2D(data.xz, rotation);
float3 localPosition = v.vertex.xyz * data.w; float3 worldPosition = data.xyz + localPosition; float3 worldNormal = v.normal;
float3 ndotl = saturate(dot(worldNormal, _WorldSpaceLightPos0.xyz)); float3 ambient = ShadeSH9(float4(worldNormal, 1.0f)); float3 diffuse = (ndotl * _LightColor0.rgb); float3 color = v.color;
v2f o; o.pos = mul(UNITY_MATRIX_VP, float4(worldPosition, 1.0f)); o.uv_MainTex = v.texcoord; o.ambient = ambient; o.diffuse = diffuse; o.color = color; TRANSFER_SHADOW(o) return o; }
fixed4 frag (v2f i) : SV_Target { fixed shadow = SHADOW_ATTENUATION(i); fixed4 albedo = tex2D(_MainTex, i.uv_MainTex); float3 lighting = i.diffuse * shadow + i.ambient; fixed4 output = fixed4(albedo.rgb * i.color * lighting, albedo.w); UNITY_APPLY_FOG(i.fogCoord, output); return output; }
ENDCG } } }