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07-Other/Unity/ComputeShader笔记.md

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+## Shader
+- RWStructuredBuffer:可读写，可用类型float1234、uint1234
+- StructuredBuffer:对应的只读BUffer
+
+## C#脚本
+### 声明变量
+CS与Buffer
+```c#
+[SerializeField]
+ComputeShader computeShader = default;
+
+ComputeBuffer positionBuffer;
+```
+
+### 绑定CS中的变量并且执行
+声明Shader中变量id以用于绑定
+```c#
+static readonly int intpositionsId = Shader.PropertyToID("_Positions"),
+				resolutionId= Shader.PropertyToID("_Resolution"),
+				stepId= Shader.PropertyToID("_Step"),
+				timeId= Shader.PropertyToID("_Time");
+```
+给变量绑定数值
+```c#
+computeShader.SetInt(resolutionId, resolution);
+computeShader.SetFloat(stepId, step);
+computeShader.SetFloat(timeId, Time.time);
+computeShader.SetBuffer(0, positionsId, positionBuffer);
+```
+执行
+```c#
+int groups = Mathf.CeilToInt(resolution / 8f);
+computeShader.Dispatch(0, groups, groups, 1);
+```
+
+### 绘制GPU Instance命令
+```c#
+//需要传入边界盒以及绘制数量
+var bounds=new Bounds(Vector3.zero,Vector3.one*(2f+2f/resolution));
+Graphics.DrawMeshInstancedProcedural(mesh, 0, material,bounds,positionBuffer.count);
+```
+
+### 多kernel
+CS可能拥有多个内核函数，此时computeShader的SetBuffer()与Dispatch()，可以通过第一个形参来设置kernel index。